The Description Processing Handbook
D-FILE Format (for Both Microsoft Windows 95/98/NT/2000/ME/XP and UNIX): The Format of a Description File (D-FILE)
Table of Contents
3.0 D-FILE Overview3.1 Record Formats
3.1.1 Field Range Symbol
3.1.2 Field Format Symbol
3.2 D-FILE Format, Version 02.01.02
3.2.1 Project Header Record
3.2.1.1 Header Record
3.2.1.2 Project Title Record
3.2.1.3 Project Comment Record
3.2.1.4 Project Header Terminator Record
3.3 Descriptions
3.3.1 Description Header Record
3.3.2 Underground (Mark) Record
3.3.3 Reset (Station Remonumentation) Record
3.3.4 Reference Object (Box Score) Record
3.3.5 Recovery History Record
3.3.6 Position Record
3.3.7 Orthometric Height Record
3.3.8 Descriptive Text Record
3.3.9 Vertical Mark Record
3.3.10 Description Terminator Record
Appendix A Summary of Codes Used in Description Files
A.1 Accession Prefix (Project Type)
A.2 Condition Code
A.3 Description Source Code
A.4 File Type Code
A.5 File Sub-type Code
A.6 Flush/Projected/Recessed (FPR) Code
A.7 Horizontal Datum Code
A.8 Latitude Hemisphere Code
A.9 Longitude Hemisphere Code
A.10 Magnetic Property Code
A.11 Monumentation (Marker) Category Code
A.12 Monumentation (Marker) Code
A.13 Object Type Code
A.14 Orthometric Height Class Code
A.15 Orthometric Height Order Code
A.16 Orthometric Height Source Code
A.17 Orthometric Height Technique Code
A.18 Orthometric Height Units
A.19 Position Order Code
A.20 Position Source Code
A.21 Position Technique Code
A.22 Projected/Recessed (PR) Distance Units
A.23 Record Identifiers
A.24 Reference Object Distance Units
A.25 Reference Object Type Code
A.26 Report Type Code
A.27 Rod/Pipe Depth Units
A.28 Satellite Usage Code
A.29 Setting (Class) Code
A.30 Sleeve Depth Units
A.31 Source Program Name
A.32 Special Application Code
A.33 Text Status
A.34 Transportation Code
A.35 Vertical Datum Code
A.36 Vertical Stability Code
Appendix B A Sample Description File (D-FILE)
D-FILE Format
The D-FILE format has been designed to accommodate two types of data: DATA SHEETs with positions, elevations, descriptive text, etc., and descriptions, which only have descriptive information. Descriptions should be seen as a subset of DATA SHEETs. D-FILES can be the output of several programs. The programs that can act on or produce a D-FILE are described in Appendix A, Source Program Names.
The following sections of this document are used to describe all the possible records found in a D-FILE. These sections are broken down by record and then by field. Each field is further broken down by: field number, field format, field length, field range, field option, field description, and field example. Some special symbols are used in the field format, field length, and the field range partitions. These special symbols are defined below.
Any field can be defined in short or long field format notation. For example, a field known as USGS quadrangle name is 10 characters long, and can contain the characters [A..Z, 0..9, -, &, (, ), space]. The field format can be represented in short notation as X(10), or in long notation as XXXXXXXXXX.
You might also see a field format like A(1-200). This means that this field is a variable length field and can have from 1 to 200 characters, and those characters are all in the set of capitalized alphabetic characters [A..Z].
3.2 D-FILE Format, Version 02.01.02
A description file, D-FILE, is made up of: (1) 1 Project Header record, and (2) 0 or more Description records.
The project header record is made up of: (1) 1 Header Record, (2) 1 Project Title Record, (3) 0 or 1 Project Comment Record, and (4) 1 Project Header Terminator Record.
The project header record is an independent record used to provide summary information about a file. Summary information includes where the descriptions originated from, what organization submitted them, when the file was created, the area covered by the project, etc. In a D-FILE a project header record is a required record.
The first sub-record in a project header record is known as the header record. This is a required sub-record for a project header record. This record is actually a standardized data set identification record that can be used among different file types.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | File Type Code | A | [D]. See values in Appendix A, File Type Code. | A code which describes the type of file it is. In a D-FILE, the file type code is always set to "D" to signify that this file is a description file. This field is set by a program that creates a D-FILE. |
| 2 | File Sub-Type Code | A | Values in Appendix A, File Sub-Type Code. | A code describing whether the file was generated from the NGS database or came from some other source (data would be new to the NGS database); This field is set by a program that creates or modifies a D-FILE. |
| 3 | File Format Version Number | 99.99.99 | [01.00.00..99.99.99]. | A number which represents the version number of the file format of the D-FILE. When the D-FILE's data structure is modified, the file format version is updated. The latest file format version number is 02.01.02. |
| 4 | Source Program Name | N(8) | Values in Appendix A, Source Program Name. | A code which contains the name of the program that created or modified the file last. |
| 5 | Source Program Version Number | 99.99.99 | [01.00.00..99.99.99]. | A number which represents the version number of the last program which created or modified the D-FILE. |
| 6 | File Creation Date | 9(8) or YYYYMMDD, where YYYY = year, MM = month, and DD = day | [18000101..present]. | A date which represents when the file was created or modified last. The creation date is generated by the program that created or modified the D-FILE. |
| Accession Code - An accession code is part of a header record. It is a code which is assigned by NGS to projects. Examples of projects are classical horizontal, Global Positioning System, differential leveling, etc. An accession code is composed of two parts: (1) Accession Prefix (a.k.a. Project Type), and (2) Accession Number (a.k.a. Project Number). | ||||
| 7 | Accession Prefix (Project Type) | AAA | Values listed in Accession Prefix (Project Type). | A code used to represent the type of project the file holds. |
| 8 | Accession Number (Project Number) | 99999999 | [1..99999999]. | A code used to represent an agency specific pointer (number) to its own archives, usually given as a cataloging symbol, which identifies the block of data, possibly supplemented by a further job code or part number designation. |
| 9 | Part Number | XXXX | [AAAA..9999]. | A supplemental number to the accession number. |
| 10 | Job Code | AN | [AA..Z9]. | A code assigned to any vertical or horizontal control project submitted to NGS. Unless a job code is specifically assigned to a project by NGS, this job code may be sequentially assigned by the submitting/reporting organization (i.e. A1, A2, ... ZZ). |
| 11 | Submitting/Reporting Organization Category Code | A | Values in ANNEX C, Contributors of Geodetic Data. | A code which represents the category of the agency or organization that submitted/reported the D-FILE to NGS. |
| 12 | Submitting/Reporting Organization Code | X(6) | Values in ANNEX C, Contributors of Geodetic Data. | The NGS-defined symbol for the agency or organization that submitted/reported the D-FILE to NGS |
| 13 | Submitting/Reporting Organization Fullname/Definition | X(80) | Values in ANNEX C, Contributors of Geodetic Data if submitting/reporting organization code is not "NEWAGY"; otherwise [A..Z, 0..9, space, -, +, (, )]. | The fullname/definition of the agency or organization that submitted/reported the D-FILE to NGS. |
| Area Covered by Project - All descriptions entered into the D-FILE must fall within the specified area covered by the project. An area is composed of four sub-records: (1) Maximum Latitude Record, (2) Minimum Latitude Record, (3) Maximum Longitude Record, and (4) Minimum Longitude Record. These records are further sub-divided into five fields: (1) hemisphere code, (2) degrees, (3) minutes, (4) seconds, and (5) decimal seconds. Information in these fields defines the rectangular boundaries of the project. | ||||
| Maximum Latitude Record - The maximum latitude represents the largest latitude that can be allowed in the D-FILE. The fields comprising the maximum latitude are hemisphere, degrees, minutes, seconds, and decimal seconds. The overall format of the maximum latitude is (H DD MM SS.sssss) where H=hemisphere, D=degrees, M=minutes, S=seconds, and s=decimal seconds. The maximum latitude must be greater than the minimum latitude. | ||||
| 14 | Hemisphere Code | A | Values in Appendix A, Latitude Hemisphere Code. | A code representing the hemisphere part of the maximum latitude. |
| 15 | Degrees | 99 | [00..90]. | A number representing the degree part of the maximum latitude. |
| 16 | Minutes | 99 | [00..59]. | A number representing the minute part of the maximum latitude. |
| 17 | Seconds | 99 | [00..59]. | A number representing the seconds part of the maximum latitude. |
| 18 | Decimal Seconds | .99999 | [.00001 .. .99999]. | The fractional portion of the maximum latitude seconds. |
| Minimum Latitude Record - The minimum latitude represents the smallest latitude that can be allowed in the D-FILE. The fields comprising the minimum latitude are hemisphere, degrees, minutes, seconds, and decimal seconds. The overall format of the minimum latitude is (H DD MM SS.sssss) where H=hemisphere, D=degrees, M=minutes, S=seconds, and s=decimal seconds. The minimum latitude must be less than the maximum latitude. | ||||
| 19 | Hemisphere Code | A | Values in Appendix A, Latitude Hemisphere Code. | A code representing the hemisphere part of the minimum latitude. |
| 20 | Degrees | 99 | [00..90]. | A number representing the degree part of the minimum latitude. |
| 21 | Minutes | 99 | [00..59]. | A number representing the seconds part of the minimum latitude. |
| 22 | Seconds | 99 | [00..59]. | A number representing the seconds part of the minimum latitude. |
| 23 | Decimal Seconds | .99999 | [.00001 .. .99999]. | The fractional portion of the minimum latitude seconds. |
| Maximum Longitude Record - The maximum longitude represents the largest longitude that can be allowed in the D-FILE. The fields comprising the maximum longitude are hemisphere, degrees, minutes, seconds, and decimal seconds. The overall format of the maximum longitude is (H DDD MM SS.sssss) where H=hemisphere, D=degrees, M=minutes, S=seconds, and s=decimal seconds. The maximum longitude must be greater than the minimum longitude. | ||||
| 24 | Hemisphere Code | A | Values in Appendix A, Longitude Hemisphere Code. | A code representing the hemisphere part of the minimum longitude. |
| 25 | Degrees | 999 | [00 to 360]. | A number representing the degree part of the minimum longitude. |
| 26 | Minutes | 99 | [00 to 59]. | A number representing the seconds part of the minimum longitude. |
| 27 | Seconds | 99 | [00 to 59]. | A number representing the seconds part of the minimum longitude. |
| 28 | Decimal Seconds | .99999 | [.00001 to .99999]. | The fractional portion of the minimum longitude seconds. |
| Minimum Longitude Record - the minimum longitude represents the smallest longitude that can be allowed in the D-FILE. The fields comprising the minimum longitude are hemisphere, degrees, minutes, seconds, and decimal seconds. The overall format of the minimum longitude is (H DDD MM SS.sssss) where H=hemisphere, D=degrees, M=minutes, S=seconds, and s=decimal seconds. The minimum longitude must be less than the maximum longitude. | ||||
| 29 | Hemisphere Code | A | Values in Appendix A, Longitude Hemisphere Code. | A code representing the hemisphere part of the maximum longitude. |
| 30 | Degrees | 999 | [00..360]. | A number representing the degree part of the maximum longitude. |
| 31 | Minutes | 99 | [00..59]. | A number representing the seconds part of the maximum longitude. |
| 32 | Seconds | 99 | [00..59]. | A number representing the seconds part of the maximum longitude. |
| 33 | Decimal Seconds | .99999 | [.00001 .. .99999]. | The fractional portion of the maximum longitude seconds. |
3.2.1.2 Project Title Record Format
The project title record consists of: (1) 1 Record Identifier, and (2) 1 Project Title.
This record is a required sub-record in the project header record. The project title record is where the user gives the project a title/name which describes the project.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [A]. See values in Appendix A, Record Identifier. | A code which tells what type of record is expected to follow. |
| 2 | Project Title | X(280) | [A..Z, 0..9, *, ,, ', =, (, -, ., +, ), /, space, \n]. | A project title holds a brief description of the project as a whole. The project title provides cross-referencing information for a project across different types of surveys. It is used for bookkeeping purposes. |
3.2.1.3 Project Comment Record Format
The project comment record consists of: (1) 1 Record Identifier, and (2) 1 Project Comment.
The project comment record is an optional sub-record in the project header record. The project comment record holds additional information on a project that isn't already in the project title record.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [B]. See values in Appendix A, Record Identifier. | A code which tells what type of record is expected to follow. |
| 2 | Project Comments | X(280) | [A..Z, 0..9, *, ,, ', =, (, -, ., +, ), /, space, \n]. | A project comment holds information about the project that the user feels might be beneficial to NGS personnel. This field is a fixed length field. Example: No Comments. |
3.2.1.4 Project Header Terminator Record Format
The project record terminator record consists of: (1) 1 Record Identifier.
The project record terminator record is an required sub-record in the project header record. The project comment record holds additional information on a project that isn't already in the project title record.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier (Terminator) | X | [\n]. See values in Appendix A, Record Identifier. | The project header record terminator character, the newline character, signifies the end of the project header record. It is a required field. |
Descriptions are what NGS uses to define characteristics about a monument or marker. The information can include the condition of the mark, the stamping on the marker, how the marker was set, some data on markers in the surrounding area, a history of the marker, and so forth.
To be more precise, a description is made up of:
- 1 Description Header Record
- 0 or 1 Underground (Mark) Record
- 0 or 1 Reset (Station Remonumentation) Record
- 0 or more Reference Object (Box Score) Records
- 0 or more Recovery History Records>
- 1 Position Record
- 0 or 1 Height Record
- 0 or 1 Descriptive Text Record
- 0 or more Vertical Mark Records
- Description Terminator Records
3.3.1 Description Header Record
The description header record is the main record in a description. This record is a required sub-record in a description record.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | X | [@]. See values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow. |
| 2 | Station Serial Number (SSN) | 9999 | [0001..9999]. | A which identifies a station within a project and is used as a cross reference between the various files in a project. The same SSN must be used for a station across all records in a project. It must be unique within each D-FILE. If the SSN number is less than 1000, the SSN field must contain leading zeros. |
| 3 | Permanent Identifier (PID) | AANNNN | [AA0001..ZZZZZZ]. | A permanent identifier assigned to every recoverable survey point in the NGSIDB. Points new to the NGS database will be assigned a PID when they are loaded. |
| 4 | Condition Code | A | Values in Appendix A, Condition Code. | A code indicating the condition or status of the monument or mark each time it is recovered. |
| 5 | Designation | X(50) | [A-Z, 0-9, =, -, ., +, /, (, ), _, &, ,, ', space] | The designation is the primary identifier by means of which the control point is known to the general public. For a mark already included in the NGS database, the designation should be given as published. For a new mark, if it is stamped, the designation is an edited version of the stamping. Detailed instructions for the assignment of designations are found in ANNEX D, Input Formats and Specifications of the National Geodetic Survey Data Base, Volume I, September 1994 (the bluebook). |
| 6 | Alias | X(50) | [A-Z, 0-9, =, -, ., +, /, (, ), _, &, ,, ', space] | An alternate name used for a control point. This is to allow for different naming conventions used by other organizations. An alias should not be created unnecessarily. |
| 7 | Stamping | X(50) | [A-Z, 0-9, =, -, ., +, /, (, ), _, &, ,, ', space] | The stamping as it appears on the geodetic control marker. |
| 8 | USGS Quadragle Name | X(35) | [A..Z, 0..9, -, &, (, ), space] | The name of the 7.5 minute X 7.5 minute quadrant off the quadrant sheet. |
| 9 | Special Application Codes | X(5) | Values in Appendix A, Special Application Code. | A code that represents a special use of the control point. More than one code from Appendix A, Special Application Code can apply to a control point. Although the special application codes field can be up to five characters in length, there are currently only a maximum of three application codes to choose from. |
| 10 | Satellite Usage Code | A | Values in Appendix A, Satellite Usage Code. | A code indicating whether the mark is suitable for use in GPS surveys. |
| 11 | Country Code | AA | Values in ANNEX A, NGS Country, State, and County Codes. | A code representing the country in which the monument or marker is located. |
| 12 | State Code | AA | Values in ANNEX A, NGS Country, State, and County Codes. | A code representing the state in which the monument or marker is located. |
| 13 | County FIPS Code | 999 | Values in ANNEX A, NGS Country, State, and County Codes. | A FIPS code representing the county FIPS code of the county in which the monument or marker is located. |
| 14 | County Fullname/Definition | A(25) | The county fullname/definition must be one of those listed in ANNEX A, NGS Country, State, and County Codes. | The fullname of the county where the monument or marker is located. |
| 15 | Monumentation (Marker) Category Code | A | Values in Appendix A, Monumentation (Monument) Category Code. | A code that identifies the category type of monument object, or landmark which represents the control point. |
| 16 | Monumentation (Marker) Code | NN | Values in Appendix A, Monumentation (Marker) Code. | A code that identifies the type of monument object, or landmark which represents the control point |
| 17 | Setting (Class) Code | 99 | Values in Appendix A, Setting (Class) Code. | A code which indicates how the mark is set. |
| 18 | Specific Setting Text | X(32) | [A..Z, 0..9]. | A field where users can put added comments about the setting. |
| 19 | Vertical Stability Code | A | Values in Appendix A, Vertical Stability Code. | A code representing the stability class of the mark. |
| 20 | Magnetic Property Code | A | Values in Appendix A, Magnetic Property Code. | A code which indicates the magnetic property of the mark or monument. |
| 21 | Flush/Projected/Recessed (FPR) Code | A | Values in Appendix A, Flush/Projected/Recessed (FPR) Code. | A code indicating whether the marker's setting is flush with (F), projects above (P), or is recessed below (R) the surrounding surface. |
| 22 | Projecting/Recessed (PR) Distance | 9999 | [0CM..999CM]. | The distance by which the marker's setting projects or is recessed. |
| 23 | Projecting/Recessed (PR) Distance Units | AA | Values in Appendix A, Projecting/Recessed (PR) Distance Units. | The units of measure for the PR distance. |
| 24 | Rod/Pipe Depth | 9999 | [0.1M..999M] | The depth of the rod or pipe. |
| 25 | Rod/Pipe Depth Units | AA | Values in Appendix A, Rod/Pipe Depth Units. | The units of measure for the rod/pipe depth. |
| 26 | Sleeve Depth | 9999 | [0.1M..999M] | The depth of the rod or pipe's sleeve. |
| 27 | Sleeve Depth Units | AA | Values in Appendix A, Sleeve Depth Units. | The units of measure for the sleeve depth. |
| 28 | Organization Logo Category Code | A | Values in ANNEX C, Contributors of Geodetic Data. | A code which represents the category of the agency or organization whose name is on the marker. |
| 29 | Organization Logo Code | X(6) | Values in ANNEX C, Contributors of Geodetic Data. | The NGS-defined symbol for the agency or organization whose name is on the marker. |
| 30 | Organization Logo Fullname/Definition | X(80) | Values in ANNEX C, Contributors of Geodetic Data if organization logo code is not "NEWAGY"; otherwise [A..Z, 0..9, space, -, +, /, (, )]. | The fullname/definition of the agency whose name is on the marker. |
| 31 | Setting/Establishing Organization Category Code | A | Values in ANNEX C, Contributors of Geodetic Data. | A code which represents the category of the agency or organization which established or set the mark. |
| 32 | Setting/Establishing Organization Code | X(6) | Values in ANNEX C, Contributors of Geodetic Data. | The NGS-defined symbol for the agency or organization which established or set the mark. |
| 33 | Setting/Establishing Organization Fullname/Definition | X(80) | Values in ANNEX C, Contributors of Geodetic Data if setting/establishing organization code is not "NEWAGY"; otherwise [A..Z, 0..9, space, -, +, /, (, )]. | The fullname/definition of the agency or organization which established or set the mark. |
| 34 | Setting Date | 9(8) or YYYYMMDD, where YYYY = year, MM = month, and DD = day | [18000101..present]. | A date which represents when the mark was established or set. |
| 35 | Recovery/Reporting Organization Category Code | A | Values in ANNEX C, Contributors of Geodetic Data. | A code which represents the category of the agency or organization which visited/recovered the mark. |
| 36 | Recovery/Reporting Organization Code | X(6) | Values in ANNEX C, Contributors of Geodetic Data. | The NGS-defined symbol for the agency or organization which visited/recovered the mark. |
| 37 | Recovery/Reporting Organization Fullname/Definition | X(80) | Values in ANNEX C, Contributors of Geodetic Data if recovery/reporting organization code is not "NEWAGY"; otherwise [A..Z, 0..9, space, -, +, /, (, )]. | The fullname/definition of the agency or organization which visited/recovered the mark. |
| 38 | Chief of Party (COP) Initials | X(3) | [A..Z, space]. | The initials of the party chief who went to the mark. |
| 39 | Recovery /Report Date | 9(8) or YYYYMMDD, where YYYY = year, MM = month, and DD = day | [18000101..present]. | A date which represents the exact date work was done at the mark. |
| 40 | Transportation Code | A | Values in Appendix A, Transportation Code. | A code which indicates the mode of transportation used to reach the station. |
| 41 | Pack Time | 9999 | [0000..9959]. | The time required to carry equipment from the last point of transportation to the station expressed in hours and minutes. |
| 42 | Report Type | A | Values in Appendix A, Report Type. | A code which indicates the immediate source of the description. This code is used to properly load descriptions into the NGS database. |
| 43 | Text Status | A | Values in Appendix A, Text Status. | A code which describes what kind of text is in the descriptive text record. |
| 44 | Description Source | A | Values in Appendix A, Description Source. | A code which indicates whether or not the description came from the database or another source. |
| 45 | Keyed-in Order | 9999 | [0001..9999]. | A number assigned to a description which represents the order in which the description was keyed-in to the D-FILE. |
3.3.2 Underground (Mark) Record Format
The underground record is an optional sub-record in a description record. There can be zero or one underground record associated with a description. Information is entered into the underground record structure whenever there is an underground marker or monument associated with the current monument or marker.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [G]. See values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow. |
| 2 | Monumentation (Marker) Category Code | A | [U]. See values in Appendix A, Monumentation (Marker) Category Code. | A code which identifies the category type of the monument object, or landmark which represents the underground control point. |
| 3 | Monumentation (Marker) Code | NN | [A..D, DD, DE, DH, DO, DR, DS, DZ, E, G..Z]. Subset of values in Appendix A, Monumentation (Marker) Code. | A code which identifies the type of monument object, or landmark which represents the underground control point. |
| 4 | Setting (Class) Code | 99 | [00, 02, 04, 15, 16, 65, 66, 80]. Subset of values in Appendix A, Setting (Class) Code. | A which indicates how the underground monument or marker is set. |
| 5 | Setting Date | 9(8) or YYYYMMDD, where YYYY = year, MM = month, and DD = day | [18000101..present]. | A date which represents the date that the underground monument or marker was set. |
| 6 | Magnetic Property Code | A | Values in Appendix A, Magnetic Property Code. | A code which indicates the magnetic property of the monument or marker. |
| 7 | Vertical Stability Code | A | Values in Appendix A, Vertical Stability Code. | A code representing the stability class of the monument or marker. |
| 8 | Record Terminator | X | [\0]. | The underground record terminator character, the null character, signifies the end of the underground record. |
3.3.3 Reset (Station Remonumentation) Record
The reset record is an optional sub-record in a description record. There can be zero or one reset record associated with a description. Information is entered into the reset record structure whenever the original monument or marker has been dislodged, or destroyed.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [H]. See values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow. |
| 2 | Permanent Identifier (PID) | AANNNN | [AA0001..ZZZZZZ]. | The PID of the old control point. A PID is a permanent identifier assigned to every recoverable survey point in the NGS database. Points new to the NGS database will be assigned a PID when they are loaded. |
| 3 | Designation | X(50) | [A-Z, 0-9, =, -, ., +, /, (, ), _, &, ,, ', space].. | The designation of the old control point. The designation is the primary identifier by means of which the control point is known to the general public. For a mark already included in the NGS database, the designation should be given as published. For a new mark, if it is stamped, the designation is an edited version of the stamping. Detailed instructions for the assignment of designations are found in ANNEX D, Input Formats and Specifications of the National Geodetic Survey Data Base, Volume I, September 1994 (the bluebook). |
| 4 | Record Terminator | X | [\0]. | The reset record terminator character, the null character, signifies the end of the reset record. |
3.3.4 Reference Object (Box Score) Record
A reference object is a station or a landmark, that an observer sees from the current mark/station. This reference record provides box score information, that is "runs", "hits", and "errors", about each reference mark. Reference objects are used as a aid in finding the main marker. Generally they are 20-50 meters from the main marker and have an arrow which points in the direction of the main marker and provide the surveyor with a distance from the main marker. A reference object record contains one sub-record: an azimuth record.
Any information appearing in a reference object record is the result of running the DS2D/WDS2D program to convert a DATA SHEET to a D-FILE. If reference object record information appears on a DATA SHEET, it is stored here in a D-FILE. This information never gets loaded into the NGS database. No reference object records exist when a new description is keyed-in or does not come from the NGS database. Therefore, if the D-FILE was not created via the DS2D/WDS2D program, no reference object records will exist. The information contained in a reference object record is FYI (for your information) only and should aid users in locating a monument (marker).
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [J]. See values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow. |
| 2 | Permanent Identifier (PID) | AANNNN | [AA0001..ZZZZZZ]. | The PID of the reference monument or marker. A PID is a permanent identifier assigned to every recoverable survey point in the NGS database. Points new to the NGS database will be assigned a PID when they are loaded. |
| 3 | Reference Object Type | A | Values in Appendix A, Object Type Code. | A code which identifies the type of object that is being referenced. |
| 4 | Reference Object Distance | 9999.999 | [.001 .. 9999.999]. | The distance from the reference monument or marker to the current monument or marker identified in the description header record. |
| 5 | Reference Object Distance Units | AA | Values in Appendix A, Reference Object Distance Units. | The units of measure for the object distance field. |
| Geodetic Azimuth Record - The primary data of interest in a reference record is the geodetic azimuth sub-record. An azimuth is the horizontal angle reckoned clockwise from the meridian. In the basic control surveys of the US, and in those of many other countries, azimuths are currently reckoned clockwise from south. In military control surveys of most countries, including the US, azimuths are reckoned clockwise from north. The geodetic azimuth in the reference record is reckoned from the north. The geodetic azimuth sub-record is divided into degrees, minutes, seconds, decimal seconds, and error. | ||||
| 6 | Degrees | 999 | [000..360]. | The degree component of the horizontal angle reckoned clockwise from the meridian. |
| 7 | Minutes | 99 | [00..59]. | The minute component of the horizontal angle reckoned clockwise from the meridian. |
| 8 | Seconds | 99 | [00..59]. | The seconds component of the horizontal angle reckoned clockwise from the meridian. |
| 9 | Decimal Seconds | .99 | [.01 .. 99]. | The decimal seconds component of the horizontal angle reckoned clockwise from the meridian. |
| 10 | Error | 99.99 | [.01 .. 99.99]. | The amount of error that is possible in the azimuth angle specified in the geodetic azimuth degrees, minutes, seconds, and decimal seconds fields. |
| 11 | Designation | X(50) | [A-Z, 0-9, =, -, ., +, /, (, ), _, &, ,, ', space]. | The designation of the reference monument or marker. The designation is the primary identifier by means of which the control point is known to the general public. For a mark already included in the NGS database, the designation should be given as published. For a new mark, if it is stamped, the designation is an edited version of the stamping. Detailed instructions for the assignment of designations are found in ANNEX D, Input Formats and Specifications of the National Geodetic Survey Data Base, Volume I, September 1994 (the bluebook). |
| 12 | Record Terminator | X | [\0]. | The reference object record terminator character, the null character, signifies the end of the reference object record. |
3.3.5 Recovery History Record Format
A recovery history record provides historical data about the current monument or marker in the description header record. There can be zero or many recovery histories for a marker.
Any information appearing in a history record is the result of running the DS2D/WDS2D program to convert a DATA SHEET to a D-FILE. If history record information appears on a DATA SHEET, it is stored here in a D-FILE. This information never gets loaded into the NGS database. No history records exist when a new description is keyed-in or does not come from the NGS database. Therefore, if the D-FILE was not created via the DS2D/WDS2D program, no history records will exist. The information contained in a history record is FYI (for your information) only. It should provide users with an idea of what has happened to the monument (marker) since the time it was originally set.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [K]. See values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow. |
| 2 | Recovery/Report Date | 9(8) or YYYYMMDD, where YYYY = year, MM = month, and DD = day | [18000101..present]. | A date which represents the exact date work was done at the mark. |
| 3 | Recovery Condition Code | A | Values in Appendix A, Condition Code. | A code indicating the condition or status of the monument or mark when it is recovered. |
| 4 | Recovery/Reporting Organization Category Code | A | Values in ANNEX C, Contributors of Geodetic Data. | A code which represents the category of the agency or organization which visited/recovered the mark. |
| 5 | Recovery/Reporting Organization Code | X(6) | Values in ANNEX C, Contributors of Geodetic Data. | The NGS-defined symbol for the agency or organization which visited/recovered the mark. |
| 6 | Recovery/Reporting Organization Fullname/Definition | X(80) | Values in ANNEX C, Contributors of Geodetic Data if recovery/reporting organization code is not "NEWAGY"; otherwise [A..Z, 0..9, space, -, +, /, (, )]. | The fullname/definition of the agency or organization which visited/recovered the mark. |
| 7 | Chief of Party Initials (COP) | XXX | [A..Z, space]. | The initials of the party chief who recovered the mark. |
| 8 | Satellite Usage Code | A | Values in Appendix A, Satellite Usage Code. | A code indicating whether the mark is suitable for use in GPS surveys. |
| 9 | Transportation Code | A | Values in Appendix A, Transportation Code. | A code which indicates the mode of transportation used to reach the station. |
| 10 | Pack Time | 9999 | [0000..9959]. | The time required to carry equipment from the last point of transportation to the station expressed in hours and minutes. |
| 11 | Historical Descriptive Text | X(0-4900) | [A..Z, 0..9, =, -, ., +, /, (, ), _, &, ,, ', *, :, ;, #, ", space, \n] | Text that describes the monument or marker at a given date indicated in the History Record's Recovery/Report Date field. |
| 12 | Record Terminator | X | [\0]. | The recovery history record terminator character, the null character, signifies the end of the recovery history record. |
The position record contains information about the exact horizontal location of the current monument or marker found in the description header record. The position record contains two sub-records: the latitude record and the longitude record. The position record itself is a required sub-record for the description record. There must be one position record in the D-FILE for each description. For users who are submitting new descriptions to NGS, the only sub-records and fields in a position record that are required are the record identifier field, the latitude sub-record, the longitude sub-record, the position source field, the horizontal datum code, and the record terminator field.
Any information appearing in the adjustment date field, the epoch field, the position order code field, and the position technique code field of a position record is the result of running the DS2D/WDS2D program to convert a DATA SHEET to a D-FILE. If this information appears on a DATA SHEET, it is stored here in a D-FILE. This information never gets loaded into the NGS database. This information does not exist when a new description is keyed-in or does not come from the NGS database. Therefore, if the D-FILE was not created via the DS2D/WDS2D program, these fields will be blank. The information in these fields is FYI (for your information) only. These fields should provide users with a better idea of the kind of position they are looking at.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [L]. See values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow. |
| Latitude Record - The latitude record contains latitude information about the current monument or marker in the description header record. The latitude record is a required sub-record for the position record. The fields comprising the latitude record are hemisphere, degrees, minutes, seconds, and decimal seconds. The overall format of the latitude is (H DD MM SS.sssss) where H=hemisphere, D=degrees, M=minutes, S=seconds, and s=decimal seconds. The latitude found in the position record must be greater than or equal to the minimum latitude in the project header record and less than or equal to the maximum latitude in the project header record. | ||||
| 2 | Hemisphere Code | A | Values in Appendix A, Latitude Hemisphere Code. | A code which represents the hemisphere part of the latitude. |
| 3 | Degrees | 99 | [00..90]. | A number which represents the degree part of the latitude. |
| 4 | Minutes | 99 | [00..59]. | A number which represents the minute part of the latitude. |
| 5 | Seconds | 99 | [00..59]. | A number which represents the seconds part of the latitude. |
| 6 | Decimal Seconds | .99999 | [.00001 .. .99999]. | The fractional portion of the latitude seconds. |
| Longitude Record - The longitude record contains longitude information about the current monument or marker in the description header record. The longitude record is a required sub-record for the position record. The fields comprising the longitude record are hemisphere, degrees, minutes, seconds, and decimal seconds. The overall format of the longitude is (H DDD MM SS.sssss) where H=hemisphere, D=degrees, M=minutes, S=seconds, and s=decimal seconds. The longitude found in the position record must be greater than or equal to the minimum longitude in the project header record and less than or equal to the maximum longitude in the project header record. | ||||
| 7 | Hemisphere Code | A | Values in Appendix A, Longitude Hemisphere Code. | A code which represents the hemisphere part of the longitude. |
| 8 | Degrees | 999 | [00..360]. | A number which represents the degree part of the longitude. |
| 9 | Minutes | 99 | [00..59]. | A number which represents the minute part of the longitude. |
| 10 | Seconds | 99 | [00..59]. | A number which represents the seconds part of the longitude. |
| 11 | Decimal Seconds | .99999 | [00001..99999]. | The fractional portion of the longitude seconds. |
| 12 | Position Source Code | A | Values in Appendix A, Position Source Code. | A code describing where the position came from. |
| 13 | Horizontal Datum Code | NN | Values in Appendix A, Horizontal Datum Code. | The commonly used abbreviation of the geodetic datum on which the horizontal coordinates are based. |
| 14 | Epoch | 9999 or YYYY, where YYYY = year | [1800..present year]. | A particular instant of time from which an event or series of events is calculated, a starting point in time to which events are referred. |
| 15 | Adjustment Date | 9(8) or YYYYMMDD, where YYYY = year, M = month, and D = day | [18000101..present]. | A date which represents the exact date that the position of the monument or marker was adjusted. |
| 16 | Position Order Code | N | Values in Appendix A, Position Order Code. | A code defining the leveling order of the position. |
| 17 | Position Technique Code | N | Values in Appendix A, Position Technique Code. | A code describing how the position was determined. |
| 18 | Record Terminator | X | [\0]. | The position record terminator character, the null character, signifies the end of the position record. |
3.3.7 Orthometric Height Record Format
The orthometric height record contains information about the exact elevation of the current monument or marker found in the description header record. The orthometric height record includes the marker's current orthometric height (elevation), the datum the orthometric height is for, and various other information pertaining to where and how the orthometric height data was collected. The orthometric height record itself is an optional sub-record for the description record. There may be zero or one orthometric height record in the D-FILE for each description. If a user chooses to submit a new description with a height record to NGS, then the only fields in a height record that are required are the record identifier field, the orthometric height field, the orthometric height units field, the orthometric height source code field, the vertical datum code field, and the record terminator field.
Any information appearing in the orthometric height record is the result of running the DS2D/WDS2D program to convert a DATA SHEET to a D-FILE. If this information appears on a DATA SHEET, it is stored here in a D-FILE. This information never gets loaded into the NGS database. This information does not exist when a new description is keyed-in or does not come from the NGS database. Therefore, if the D-FILE was not created via the DS2D/WDS2D program, these fields will be blank. The information in these fields is FYI (for your information) only. These fields should provide users with more information on the height they are looking at.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [M]. See values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow. |
| 2 | Orthometric Height | 99999.9999 | [0.0001..99999.9999]. | The distance, in the direction of the zenith, between the top and bottom of an object (i.e. the height of a building or the height of a person). Can be negative. Leading zeros are not needed. |
| 3 | Orthometric Height Units | AA | Values in Appendix A, Orthometric Height Units. | The units of measure for the orthometric height. |
| 4 | Orthometric Height Source Code | A | Values in Appendix A, Orthometric Height Source Code. | A code which describes where the orthometric height (elevation) came from. |
| 5 | Vertical Datum Code | NN | Values in Appendix A, Vertical Datum Code. | The commonly used abbreviation of the vertical datum on which the vertical coordinates are based. |
| 6 | Epoch | 9999 or YYYY, where YYYY = year | [1800..present year]. | A particular instant of time from which an event or series of events is calculated, a starting point in time to which events are referred. |
| 7 | Adjustment Date | 9(8) or YYYYMMDD, where YYYY = year, M = month, and D = day | [18000101..present]. | A date which represents the exact date that the height of the monument or marker was adjusted. |
| 8 | Orthometric Height Order Code | N | Values in Appendix A, Orthometric Height Order Code. | A code defining the order of the orthometric height. |
| 9 | Orthometric Height Class Code | N | Values in Appendix A, Orthometric Height Class Code. | A code which (1) provides the user of the survey with an immediate rough, but usually sufficient estimate of the precision of the orthometric height data being used and (2) provides the surveying organization with an efficient way of controlling the precision of surveys. Orthometric height class code is a subdivision of orthometric height order code. |
| 10 | Orthometric Height Technique Code | N | Values in Appendix A, Orthometric Height Technique Code. | A code describing how the orthometric height (elevation) was determined. |
| 11 | Record Terminator | X | [\0]. | The orthometric height record terminator character, the null character, signifies the end of the orthometric height record. |
3.3.8 Descriptive Text Record Format
The descriptive text record provides textual information describing the current monument or marker in the description header record. If the marker has changed or does not have completed text, then new or updated text goes here. The text record can be a required, or optional sub-record in the description record, depending on the value of the condition code in the description header record.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [T]. Values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow |
| 2 | Descriptive Text | X(0-4900) | [A..Z, 0..9, =, -, ., +, /, (, ), _, &, ,, ', *, :, ;, #, ", space, \n] | Text that describes the current monument or marker. |
| 3 | Record Terminator | X | [\0]. | The descriptive text record terminator character, the null character, signifies the end of the descriptive text record. |
3.3.9 Vertical Mark Record Format
NGS and the Ocean Products and Services Division (OPSD) have made an effort to integrate OPSD's tidal bench mark data with the NGS database (NGSIDB). The D-FILE may have zero or more tidal bench marks associated with a description. These tidal bench marks are associated/linked to individual descriptions by the PID field in a description. The PID field is located in the description header record. The vertical mark record provides information describing the vertical mark(s) that are associated with a description via the PID field.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Record Identifier | A | [V]. Values in Appendix A, Record Identifiers. | A code which tells what type of record is expected to follow. |
| 2 | Vertical Mark (VM) Number | 9(6) | [1..999999] | NGS is integrating the NGS integrated database (a.k.a. NGSIDB), with the tidal benchmark database of the Ocean Products and Services Division (OPSD). The vertical mark number is the number assigned to a tidal bench mark by OPSD. |
| 3 | Record Terminator | X | [\0]. | The vertical mark record terminator character, the null character, signifies the end of the vertical mark record. |
3.3.10 Description Terminator Record Format
The description terminator record is used to signify that the end of the description was reached. Not only is this sub-record a required record for the description record, but it also must be the last sub-record in any description record.
| Field No. | Field Name | Field Format | Field Range | Field Description |
| 1 | Description Terminator | X | [\n] (newline character). See values in Appendix A, Record Identifiers. | A code which consists of a single newline character. This character signifies that we have reached the end of the description record. |
A. Appendix A - Summary of Codes Used in Description Files
This Appendix contains lists of codes that are used in the preparation of projects, station descriptions, and recovery notes pertaining to geodetic control points.
A.1 Accession Prefix (Project Type)
An accession prefix is a one, two, or three-character code used to represent the type of project data the file holds.
| Accession Prefix | Definition |
| A | Astronomy |
| D | Doppler satellite |
| G | (Geodetic) classical horizontal |
| GPS | Global Positioning System |
| GTZ | Geodetic Triangulation Computations |
| L | Leveling (differential) |
| ON | Old number: 5-digit leveling horizontal |
| P | Gravity |
| T | Three dimensional |
| TG | Trigonometric leveling |
| W | Water level transfers |
A condition code is a one-character code indicating the condition or status of the mark (monument) each time it is recovered.
| Condition Code | Definition |
| G | Recovered in good condition |
| N | Not recovered, not found |
| O | Other (see description for details) |
| P | Poor, disturbed, mutilated |
| S | Original setting (mark set on this date) |
| X | Surface mark known destroyed |
| Y | Underground mark destroyed |
The description source code is a one-character code indicating whether or not the description came from the NGS database.
| Description Source Code | Definition |
| D | Description is from the NGS database (NGSIDB) |
| N | Description is from a source other than NGSIDB |
The file type code field is a one-character code that describes the type of file you are creating. Currently, there is only one file type code.
| File Type Code | Definition |
| D | Description |
The file sub-type code field is a one-character code describing the origins of the data.
| File Sub-Type Code | Definition |
| N | New Description (new to NGSIDB) |
| H | Old Horizontal Description |
| R | Retrieved from the Database (NGSIDB) |
| U | Old Unified Description |
| V | Old Vertical Description |
The programs that can modify the file subtype field are: DS2D/WDS2D, EXTRACT/WEXTRACT, MRGDESC/WMRGDESC, DESC/WDESC, OLDU2NEW, OLDV2NEW, and OLDH2NEW. Below is a diagram showing what valid file subtype codes come into and out of each of these program. Please refer to the specific documentation for each program for more details.
A.6 Flush/Projected/Recessed (FPR) Code
A fpr code is a one-character code indicating whether the marker's setting is flush with (F), projects above (P), or is recessed below (R) the surrounding surface.
| FPR Code | Definition |
| F | Flush |
| P | Projected |
| R | Recessed |
The horizontal datum code is a code which represents the commonly used abbreviation of the geodetic datum on which the horizontal coordinates are based.
| Horizontal Datum Code | Definition |
| 00 | Undetermined |
| 27 | North American Datum of 1927 (NAD27) |
| 64 | International Great Lakes Datum of 1964 (IGLD64) |
| 72 | World Geodetic System of 1972 (WGS72) |
| 83 | North American Datum of 1983 (NAD83) |
| 84 | World Geodetic System of 1984 (WGS84) |
| 93 | International Terrestrial Reference Frame 1993, ITRF |
| 94 | International Terrestrial Reference Frame 1994, ITRF |
| 96 | 96 - International Terrestrial Reference Frame 1996, ITRF |
| 97 | 97 - International Terrestrial Reference Frame 1997, ITRF |
| AN | Anchorage Pt Astro |
| AS | American Samoa 1962 (ASD62) |
| BA | Barter Island 1948 |
| BS | BS-Bessel Spheroid |
| CC | Camp Colona 1890 |
| CS | Charleston and Savannah |
| FX | Flaxman Island 1912 |
| GO | Golofin Bay 1899 |
| GU | Guam Datum 1963 |
| HI | Old Hawaiian Datum |
| IL | Iliamna Astro |
| KW | Kripniyuk-Kwiklokchun |
| MI | Mary Is Pt Simpson Astro |
| MQ | Midway Astro 1961 |
| NO | New Orleans and Mobile |
| PB | Point Barrow 1945 |
| PC | Port Clarence Astro |
| PR | Puerto Rican Datum |
| PW | Prince William Sound |
| SE | Southeast Alaska |
| SG | St George 1897 |
| SM | Saint Michael Astro |
| SP | Saint Paul 1897 |
| UN | Unalaska |
| US | United States Standard Datum |
| VD | Valdez |
| YA | Yakutat 1892 |
| YK | Yukon |
The latitude hemisphere code is the hemisphere that the latitude degrees, minutes, seconds, decimal seconds are for.
| Latitude Hemisphere Code | Definition |
| N | North |
| S | South |
The longitude hemisphere code is the hemisphere that the longitude degrees, minutes, seconds, decimal seconds are for.
| Longitude Hemisphere Code | Definition |
| E | East |
| W | West |
The magnetic property code is a one-character code which indicates the magnetic property of the mark or monument.
| Magnetic Property Code | Definition |
| A | Steel rod adjacent to monument |
| B | Bar magnet imbedded in monument |
| H | Bar magnet set in drill hole |
| I | Marker is a steel rod |
| M | Marker equipped with bar magnet |
| N | No magnetic material |
| O | Other (see description) |
| P | Marker is a steel pipe |
| R | Steel rod imbedded in monument |
| S | Steel spike imbedded in monument |
| T | Steel spike adjacent to monument |
A.11 Monumentation (Marker) Category Code
The monumentation category code is a one character code which identifies the category type of the monument object, or landmark which represents the control point.
| Monumentation Category Code | Definition |
| D | Disk monument |
| L | Landmark monument |
| O | Other monument |
| R | Rod monument |
| U | Underground monument |
A.12 Monumentation (Marker) Code
The monumentation code is a one or two character code which identifies the type of monument object or landmark which represents the control point. Monumentation codes are subdivided into five monument categories: disk monuments (D), landmark monuments (L), other monuments (O), rod monuments (R), and underground monuments (U). Some monumentation codes appear in more than one category. The monumentation codes are also divided into generalized categories (see the grayed-out headings) for your convenience. This table is represented by the MONUCAT.DAT, and the MONUMENT.DAT ASCII files.
| Monumentation Category | Monumentation Code | Definition |
| Not for Landmark Stations | ||
| O, U | A | Aluminum marker other than a disk included elsewhere in table |
| O, U | B | Bolt |
| O, U | C | Cap of cap-and-bolt pair |
| D | DA | Astro pier disk |
| D | DB | Bench mark disk |
| D, U | DD | Survey disk (other agency) |
| D, U | DE | Traverse station disk |
| D | DG | Gravity station disk |
| D, U | DH | Horizontal control disk |
| D | DJ | Tidal station disk |
| D | DK | Gravity reference mark disk |
| D | DM | Magnetic station disk |
| D, U | DO | Disk not specified (see description) |
| O | DP | Base line pier disk |
| D | DQ | Calibration base line disk |
| D, U | DR | Reference mark disk |
| D, U | DS | Triangulation station disk |
| D | DT | Topographic station disk |
| D | DU | Boundary marker |
| D | DV | Vertical control disk |
| D | DW | NOS hydrographic survey disk |
| D, U | DZ | Azimuth mark disk |
| O, U | E | Earthenware pot |
| R | F | Flange-encased rod |
| O, U | G | Glass bottle |
| O, U | H | Drill hole |
| R, U | I | Metal rod |
| O, U | J | Earthenware jug |
| O, U | K | Clay tile pipe |
| O, U | L | Gravity plug |
| O, U | M | Ammo shell casing |
| O, U | N | Nail |
| O, U | O | Chiseled circle |
| O, U | P | Pipe cap |
| O, U | Q | Chiseled square |
| O, U | R | Rivet |
| O, U | S | Spike |
| O, U | T | Chiseled triangle |
| O, U | U | Concrete post (without other marks) |
| O, U | V | Stone monument |
| O, U | W | Unmonumented |
| O, U | X | Chiseled cross |
| O, U | Y | Drill hole in brick |
| O, U | Z | See description |
| Landmarks not Listed | ||
| L | 0 | Other mark or intersection station, see description |
| Natural Objects | ||
| L | 01 | Lone tree |
| L | 02 | Conspicuous rock |
| L | 03 | Mountain peak |
| L | 04 | Rock pinnacle |
| L | 05 | Rock awash |
| Waterfront Landmarks and Visual Aids to Navigation | ||
| L | 11 | Piling |
| L | 12 | Dolphin |
| L | 13 | Lighthouse |
| L | 14 | Navigation light |
| L | 15 | Range marker |
| L | 16 | Daybeacon |
| L | 17 | Flag tower |
| L | 18 | Signal mast |
| Aeronautical and Electronic Aids to Navigation | ||
| L | 21 | Airport beacon |
| L | 22 | Airway beacon |
| L | 23 | VOR antenna |
| L | 24 | REN antenna |
| L | 25 | Radar antenna |
| L | 26 | Spherical radome |
| L | 27 | Radio range mast |
| L | 28 | LORAN mast |
| Broadcast and Communications Facilities | ||
| L | 41 | Antenna mast |
| L | 42 | Radio/TV mast |
| L | 43 | Radio/TV tower |
| L | 44 | Microwave mast |
| L | 45 | Microwave tower |
| Tanks and Towers | ||
| L | 51 | Tank |
| L | 52 | Standpipe tank |
| L | 53 | Elevated tank |
| L | 54 | Water tower |
| L | 55 | Tower |
| L | 56 | Skeleton tower |
| L | 57 | Lookout tower |
| L | 58 | Control tower |
| Miscellaneous Landmarks | ||
| L | 61 | Pole |
| L | 62 | Flagpole |
| L | 63 | Stack |
| L | 64 | Silo |
| L | 65 | Grain elevator |
| L | 66 | Windmill |
| L | 67 | Oil derrick |
| L | 68 | Commercial sign |
| L | 69 | Regulatory sign |
| L | 70 | Monument |
| L | 71 | Boundary monument |
| L | 72 | Cairn |
| L | 73 | Lookout house |
| L | 74 | Large cross |
| L | 75 | Belfry |
| Features of a Building | ||
| L | 81 | Gable |
| L | 82 | Finial |
| L | 83 | Flagstaff |
| L | 84 | Lightning rod |
| L | 85 | Chimney |
| L | 86 | Cupola |
| L | 87 | Dome |
| L | 88 | Observatory dome |
| L | 89 | Spire |
| L | 90 | Church spire |
| L | 91 | Church cross |
| L | 92 | Antenna on roof |
| L | 93 | Microwave antenna on building |
| L | 94 | Rooftop ventilator |
| L | 95 | Rooftop blockhouse |
The object type code is a one-character code which identifies the type of object that is being referenced.
| Object Type Code | Definition |
| A | Primary Azimuth |
| B | Secondary Azimuth |
| N | Network Control |
| R | Reference |
| Z | Azimuth |
A.14 Orthometric Height Class Code
The orthometric height class code is a one-character code which (1) provides the user of the survey with an immediate, rough, but usually sufficient estimate of the precision of the orthometric height data being used and (2) provides the surveying organization with an efficient way of controlling the precision of surveys. Orthometric height class is a subdivision of orthometric height order.
| Orthometric Height Class Code | Definition |
| 0 | Class 0 |
| 1 | Class 1 |
| 2 | Class 2 |
| N | Not determined |
A.15 Orthometric Height Order Code
The orthometric height order code is a one-character code which defines the order of the orthometric height.
| Orthometric Height Order Code | Definition |
| 1 | First order |
| 2 | Second order |
| 3 | Third order |
| 4 | Fourth order |
| W | Weak, less than fourth order |
A.16 Orthometric Height Source Code
The orthometric height source code is a one-character code which describes where the orthometric height (elevation) came from.
| Orthometric Height Source Code | Definition |
| A | Last official adjusted |
| B | Unchecked adjusted |
| C | Computed using uncorrected height differences |
| F | Unadjusted field |
| H | HNB elevation |
| M | Older OBS applied to adjusted height generated from a more recent survey |
| N | Height from precise leveling connected at only one NSRS pt - for GPS check. |
| O | Other |
| P | Posted bench mark |
| R | Reset computation |
| S | Scaled, approximate |
| U | Unvalidated height from precise leveling connected at only one NSRS pt |
| X | Superseded adjustment |
A.17 Orthometric Height Technique Code
The orthometric height technique code is a one-character code which describes how the orthometric height (elevation) was determined.
| Orthometric Height Technique Code | Definition |
| A | Altimetry |
| B | Precise level from a bench mark |
| D | Doppler |
| F | Fly level |
| G | GPS |
| H | Level between control points not connected to bench mark |
| N | Normal differential leveling |
| P | Photogrammetric |
| T | Trigonometric leveling |
The orthometric height units are the units of measure for the orthometric height.
| Orthometric Height Units | Definition |
| FT | Feet |
| M | Meters |
The position order code is a one-character code which defines the leveling order of the position.
| Position Order Code | Definition |
| 0 | Network Relative Accuracy |
| 1 | First order |
| 2 | Second order |
| 3 | Third order |
| 4 | Fourth order, Hand held 1, Hand held 2 |
| A | A order |
| B | B order |
| W | Weak |
The position source code is a one-character code which describes where the position came from. This field is part of the position record.
| Position Source Code | Definition |
| A | Last official adjusted |
| O | Other |
| S | Scaled, approximate |
The position technique code is a one-character code which describes how the position was determined.
| Position Technique Code | Definition |
| 1 | From USGS, based on 3rd order or better survey that is missing from NGSIDB |
| 2 | Based on USGS transit traverse data |
| 3 | Digitized by USGS from stable base media |
| 4 | Digitized by USGS from paper media |
| 5 | USGS hand plotted and scaled |
| A | Trilateration |
| B | Inertial |
| C | Combined |
| D | Doppler |
| E | Traverse |
| F | Triangulation |
| G | GPS |
| H | Resection |
| I | Intersection |
| J | Transcontinental traverse |
| L | Datum transformation program LEFTI |
| N | Datum transformation program NADCON4 |
| P | Photogrammetric |
| V | VLBI |
| W | Hand Held 2 (AGPS) |
| X | Hand Held 1 (DGPS) |
A.22 Projected/Recessed (PR) Distance Units
The pr distance units are the units of measure for the pr distance.
| PR Distance Units | Definition |
| CM | Centimeter |
| IN | Inch |
A D-FILE is composed of:
- 1 project header record
- 0 or more description records
A project header record, in turn, is broken down into sub-records: a header record, a project title record, and a comment record. Similarly, a description record is, composed of sub-records: a description header record, an underground record, a reset record, a reference objects (box score) record, a recovery history record, a position record, an orthometric height record, a descriptive text record, and a description terminator record. The record identifier tells what type of project sub-record or description sub-record is expected to follow.
| Record Identifier | Definition |
| A | Project Title Record |
| B | Project Comment Record |
| @ | Description Header Record |
| G | Underground Record |
| H | Reset (Station Remonumentation) Record |
| J | Reference Object (Box Score) Record |
| K | Recovery History Record |
| L | Position Record |
| M | Orthometric Height Record |
| T | Descriptive Text Record |
| V | Vertical Mark Record |
| \n | Terminator Record |
A header record, a sub-record of the project header record, does not have any record identifier.
A.24 Reference Object Distance Units
The reference object distance units are the units of measure for the reference object distance.
| Reference Object Distance Units | Definition |
| M | Meter |
| KM | Kilometer |
A.25 Reference Object Type Code
The object type code is a one-character code which identifies the type of object that is being referenced.
| Object Type Code | Definition |
| A | Primary azimuth |
| B | Secondary Azimuth |
| N | Network control |
| R | Reference |
| Z | Azimuth |
The report type code is a one-character code indicating the immediate source of the description. This code is used to properly load descriptions into the NGS database.
| Report Type Code | Definition |
| H | H_DESC_TEMP or files in horizontal format |
| I | Independent recoveries not in unified format |
| N | New description format |
| P | From old point GPS table; no text exists |
| S | From synoptic table entry only; no text exists |
| U | Post-breakup old unified description files |
| V | V_DESC or files in old vertical format |
| X | Do not load this description in the NGSIDB (12/11/06) |
The rod/pipe depth units are the units of measure for the rod/pipe depth.
| Rod/Pipe Depth Units | Definition |
| FT | Feet |
| M | Meters |
The satellite usage code is a one-letter code which indicates whether the mark is suitable for use in GPS surveys.
| Satellite Usage Code | Definition |
| Y | Yes mark is suitable for GPS use |
| N | No mark is not suitable for GPS use |
| Blank - GPS suitability unknown |
The setting code is a one or two-digit code which indicates how the mark is set. Setting codes are subdivided into two setting categories: surface marker settings (S), and underground marker settings(U). Some setting (class) codes appear in more than one category. The setting (class) codes are also divided into generalized categories (see the grayed-out headings) for your convenience. This table is represented by the SMONUSET.DAT, the UMONUSET.DAT, and the SETTING.DAT ASCII files.
| Setting Categories | Setting (Class) Code | Definition | Default Vertical Stability |
| Shallow Settings (less than 10 feet or 3.048 meters deep) | |||
| S, U | 0 | Unspecified setting | D |
| S, U | 2 | Object driven into ground | D |
| S, U | 4 | Object surrounded by mass of concrete | D |
| S | 7 | Set in top of concrete monument | C |
| S | 9 | Set in prefabricated concrete post | D |
| S, U | 15 | A metal rod driven into ground. See text for additional information. | D |
| S, U | 16 | A metal rod with base plate buried/screwed into ground | D |
| S | 17 | Set into or fastened to top of metal pipe driven into ground | D |
| S | 21 | Set in concrete in a clay tile pipe | D |
| Settings in Structures | |||
| S | 30 | Light structures (other than listed below) | D |
| S | 31 | Pavement (street, sidewalk, curb, etc.) | D |
| S | 32 | Retaining wall or concrete ledge | C |
| S | 33 | Piles or poles (e.g. spike in utility pole) | D |
| S | 34 | Footings of small/medium structures | C |
| S | 35 | Mat foundation or concrete slab other than pavement | C |
| S | 36 | Massive structures (other than listed below) | B |
| S | 37 | Massive retaining walls | B |
| S | 38 | Abutment or pier of large bridges | B |
| S | 39 | Tunnels | B |
| S | 40 | Large structures with deep foundations | A |
| S | 41 | Large structure with foundations on bedrock | A |
| Unsleeved Deep Settings (10ft+ or 3.048M+) | |||
| S | 45 | Unspecified deep unsleeved setting (10FT+ or 3.048M+) | C |
| S | 46 | Copper-clad steel rod without sleeve (10FT+ or 3.048M+) | B |
| S | 47 | Galvanized steel pipe without sleeve (10FT+ or 3.048M+) | B |
| S | 48 | Galvanized steel rod without sleeve (10FT+ or 3.048M+) | B |
| S | 49 | Stainless steel rod without sleeve (10FT+ or 3.048M+) | B |
| S | 50 | Aluminum alloy rod without sleeve (10FT+ or 3.048M+) | B |
| Sleeved Deep Settings (10FT+ or 3.048M+) | |||
| S | 55 | Unspecified pipe/rod in sleeve (10FT+ or 3.048M+) | B |
| S | 56 | Copper-clad rod in sleeve (10FT+ or 3.048M+) | B |
| S | 57 | Galvanized steel pipe in sleeve (10FT+ or 3.048M+) | B |
| S | 58 | Galvanized steel rod in sleeve (10FT+ or 3.048M+) | B |
| S | 59 | Stainless steel rod in sleeve (10FT+ or 3.048M+) | B |
| S | 60 | Aluminum alloy rod in sleeve (10FT+ or 3.048M+) | B |
| Settings in Rocks or Boulders | |||
| S, U | 65 | Unspecified rock or boulder | B |
| S, U | 66 | In rock outcrop or ledge | A |
| S, U | 80 | In a boulder | C |
The sleeve depth units are the units of measure for the sleeve depth.
| Sleeve Depth Units | Definition |
| FT | Feet |
| M | Meters |
The source program name is the name of the program that last created/modified the D-FILE.
| Source Program Name | Definition |
| CHKDDESC | Program Validates a D-FILE's component records, namely the project header record, and the description records. If the program found any errors in the data, then "NOLOAD" is placed in this field. Program is for NGS in-house use only. |
| DESC | A UNIX Vermont Views interactive program that allows the user to enter, edit, and view D-FILE information. All new descriptions entered into the D-FILE with this program are modifiable. Program is for NGS in-house use only. |
| DISCREP | A UNIX program which finds any discrepancies between D-FILE descriptions and descriptions in the NGS database (NGSIDB). If the program found any errors in the data, then "NODISCRE" is placed in this field. Program is for NGS in-house use only. |
| DS2D | A UNIX Vermont Views program which converts a DSDATA file (containing DATA SHEETs) to a D-FILE. Descriptions in this D-FILE are view only. Program is for NGS in-house use only. |
| EXTRACT | A UNIX Vermont Views program which allows the user to create a new D-FILE containing all or a subset of the descriptions in a D-FILE. Descriptions in the new D-FILE are modifiable. Program is for NGS in-house use only. |
| HANDHELD | Used for loading hand held GPS positions only. |
| LOAD_DESC | A UNIX program which loads descriptions from a D-FILE into the NGS database (NGSIDB). Program is for NGS in-house use only. |
| MARKATTR | Used for loading mark attributes only. |
| MRGDESC | A UNIX Vermont Views program which merges two D-FILEs together. Program is for NGS in-house use only. |
| NEIGHBOR | A UNIX program which finds all neighboring marks in the NGS database for each mark in the D-FILE. Program is for NGS in-house use only. |
| NUMDESC | A UNIX Vermont Views program which renumbers the SSN field of description records in a D-FILE. Program is for NGS in-house use only. |
| OLDU2NEW | A UNIX program which converts a unified description file to a D-FILE. Descriptions in the D-FILE are modifiable. Program is for NGS in-house use only. |
| OLDH2NEW | A UNIX program which converts an old horizontal file to a D-FILE. Descriptions in the D-FILE are modifiable. Program is for NGS in-house use only. |
| OLDV2NEW | A UNIX program which convert an old vertical file to a D-FILE. Descriptions in the D-FILE are modifiable. Program is for NGS in-house use only. |
| PRTDESC | A UNIX Vermont Views program which prints the various records of a D-FILE including a project header record, and the component records of a description record. Program is for NGS in-house use only. |
| UPD30 | Really the UPD_DFILE30 program. A UNIX program which updates a vertical observation file's observations with D-FILE description information. One can generate a D-FILE of descriptions without PIDs (ACRNs) via the program, as well as a D-FILE of descriptions that have no corresponding observation data. Program is for NGS in-house use only. |
| WCHKDESC | A Microsoft Windows program which validates a D-FILE's component records, namely the project header record, and the description records. If the program found any errors in the data, then "NOLOAD" is placed in this field. |
| WDESC | A Microsoft Windows interactive program that allows the user to enter, edit, and view D-FILE information. All new descriptions entered into the D-FILE with this program are modifiable. |
| WDS2D | A Microsoft Windows program which converts a DSDATA file (containing DATA SHEETs) to a D-FILE. Descriptions in this D-FILE are view only. |
| WEXTRACT | A Microsoft Windows program which allows the user to create a new D-FILE containing all or a subset of the descriptions in a D-FILE. Descriptions in the new D-FILE are modifiable. |
| WMRGDESC | A Microsoft Windows program which merges two D-FILEs together. |
| WNUMDESC | A Microsoft Windows program which renumbers the SSN field of description records in a D-FILE. |
| WPRTDESC | A Microsoft Windows program which prints the various records of a D-FILE including a project header record, and the component records of a description record. |
A special application code is a one-character code that represents a special use of the control point. More than one special application code can apply to a control point.
| Special Application Code | Definition |
| F | Fault monitoring site |
| O | Other special application, see descriptive text |
| T | Tidal station |
| W | Water level station |
A one-character code which describes what kind of text is in the descriptive text.
| Text Status | Definition |
| C | Complete, 1 pt., self-sufficient text that has been implicitly superseded |
| I | Text assumed to be incomplete |
| N | No text |
A one-letter code which indicates the mode of transportation used (or to be used) to reach the station or to reach the location where packing is begun if packing to the station site is required.
| Transportation Code | Definition |
| A | Light airplane |
| B | Boat |
| C | Car (or station wagon) |
| F | Float airplane |
| H | Helicopter |
| O | Other (see descriptive text) |
| P | Light truck (pickup, carryall, etc.) |
| T | Truck (larger than 3/4 ton) |
| W | Tracked vehicle (weasel, snowcat, etc.) |
| X | Four-wheel drive vehicle |
The vertical datum code is a code which represents the commonly used abbreviation of the vertical datum on which the vertical coordinates are based.
| Vertical Datum Code | Definition |
| 00 | Other |
| 29 | National Geodetic Vertical Datum of 1929 (NGVD29) |
| 55 | International Great Lakes Datum of 1955 |
| 85 | International Great Lakes Datum of 1985 |
| 88 | North American Vertical Datum of 1988 (NAVD88) |
| AS | American Samoa Vertical Datum of 2002 (ASVD02) |
| G1 | Guam Vertical Datum of 1963 (GUVD63) |
| GU | Guam Vertical Datum of 2004 (GUVD04) |
| LT | Local Tidal Datum |
| NM | Northern Marianas Vertical Datum of 2003 |
| PR | Puerto Rico Vertical Datum of 2002 (PRVD02) |
| VI | Virgin Islands Vertical datum of 2009 (VIVD09) |
The vertical stability code is a one-letter code representing the stability class of the mark.
| Vertical Stability Code | Definition |
| A | Monuments of the most reliable nature which are expected to hold their position/elevation well |
| B | Monuments which probably hold their positions/elevations well |
| C | Monuments which may hold their positions/elevations well, but which are commonly subject to surface ground movements. |
| D | Monuments of questionable or unknown reliability |
Appendix B - A Sample Description File (D-FILE)
The sample D-FILE below is the output D-FILE from the WEXTRACT program. This D-FILE contains 5 descriptions with SSNs of 0050, 0054, 0055, 0056, and 0058. These SSNs are highlighted in red and bolded for readablilty.
DN02.01.02WEXTRACT02.00.0720010724 AA N303540 N301207 W0852234 W0845757 A B
@0050BE2893GCAL 4 H FLDNR CAL 4H 1980 CLB JUNIPER CREEK (1993) USFL CALHOUN DE07 CNR25.0CM MNONE NONE DEFINED FLDNR 1980 FLDNR 1980 P0000NCD0050K1980 SCFLDNR FLORIDA DEPARTMENT OF NATURAL RESOURCES P0000DESCRIBED BY FL DEPT OF NAT RES 1980 4.55 MI WEST FROM CLARKSVILLE. BEGIN AT THE U.S. POST OFFICE IN CLARKSVILLE, PROCEED 4.55 MILES WEST ALONG STATE HIGHWAY 20 TO THE MARK. THE MARK BEARS 28.2 FEET NORTH OF HIGHWAY 20 CENTERLINE, 31.3 FEET EAST-SOUTHEAST OF PHONE CABLE BOX FRE, 74.0 FEET EAST-SOUTHEAST OF AN 11-INCH DIAMETER PINE TREE, AND 15 FEET SOUTH OF A METAL WITNESS POST. THE MARK IS 1 FT BELOW HIGHWAY. LN302600 W0851545 S83 M 52.366 M A88 199106 21
@0054BE2902GCAL 5 H RM 1 FLDNR CAL 5H NO 1 1980 BSM JUNIPER CREEK (1993) USFL CALHOUN DR07 CNR20.0CM MNONE NONE DEFINED FLDNR 1980 FLDNR 1980 P0000NCD0054K1980 SCFLDNR FLORIDA DEPARTMENT OF NATURAL RESOURCES P0000DESCRIBED BY FL DEPT OF NAT RES 1980 8.3 MI NE FROM YOUNGSTOWN. BEGIN AT THE INTERSECTION OF U.S. HIGHWAY 231 AND STATE HIGHWAY 20 NORTH OF YOUNGSTOWN, PROCEED 6.5 MILES EAST ALONG HIGHWAY 20 TO THE JUNCTION OF A SAND ROAD LEADING NORTH THROUGH A PLANTED PINE FOREST, PROCEED 0.55 MILE NORTH ALONG THE SAND ROAD TO A CROSSROAD, PROCEED WEST 0.3 MILE ALONG THE EAST/WEST SAND ROAD TO THE MARK. THE MARK BEARS 5.0 FEET NORTH OF THE ROAD CENTERLINE, 38.75 FEET WEST OF BENCH MARK CAL 5H 1980 BSM, 42 FEET WEST-NORTHWEST OF A WITNESS POST, AND 80.8 FEET SOUTHWEST OF ANOTHER WITNESS POST. LN302622 W0851959 S83 M 52.351 M A88 199106 21
@0055BE2903GCAL 5 H RM 2 FLDNR CAL 5H NO 2 1980 BSM JUNIPER CREEK (1993) USFL CALHOUN DR07 CNR20.0CM MNONE NONE DEFINED FLDNR 1980 FLDNR 1980 P0000NCD0055K1980 SCFLDNR FLORIDA DEPARTMENT OF NATURAL RESOURCES P0000DESCRIBED BY FL DEPT OF NAT RES 1980 8.3 MI NE FROM YOUNGSTOWN. BEGIN AT THE INTERSECTION OF U.S. HIGHWAY 231 AND STATE HIGHWAY 20 NORTH OF YOUNGSTOWN, PROCEED 6.5 MILES EAST ALONG HIGHWAY 20 TO THE JUNCTION OF A SAND ROAD LEADING NORTH THROUGH A PLANTED PINE FOREST, PROCEED 0.55 MILE NORTH ALONG THE SAND ROAD TO A CROSSROAD, PROCEED WEST 0.3 MILE ALONG THE EAST/WEST SAND ROAD TO THE MARK. THE MARK BEARS 59.75 FEET NORTH OF THE ROAD CENTERLINE, 60.7 FEET NORTH-NORTHEAST OF BENCH MARK CAL 5H 1980 BSM, 2.9 FEET SOUTH OF A WITNESS POST, AND 72.4 FEET NORTH-NORTHEAST OF ANOTHER WITNESS POST. LN302622 W0851959 S83 M 52.221 M A88 199106 21
@0056BE2852GCAL 6 FLDNR CAL 6 1980 BSM ALTHA WEST (1993) USFL CALHOUN DB07 CNR30.0CM MNONE NONE DEFINED FLDNR 1980 FLDNR 1980 P0000NCD0056K1980 SCFLDNR FLORIDA DEPARTMENT OF NATURAL RESOURCES P0000DESCRIBED BY FL DEPT OF NAT RES 1980 1.1 MI SOUTH FROM ALTHA. BEGIN AT THE U.S. POST OFFICE IN ALTHA, PROCEED 1.1 MILES SOUTH ALONG STATE HIGHWAY 71 TO THE MARK. THE MARK BEARS 16.5 FEET EAST OF HIGHWAY 71 CENTERLINE, 26.0 FEET NORTH OF A DIRT ROAD CENTERLINE, 12.0 FEET WEST OF A POWER POLE, AND 2.9 FEET WEST OF A WITNESS POST. THE MARK IS 1 FT BELOW HIGHWAY. LN303315 W0850739 S83 M 62.442 M A88 199106 21
@0058BE2853GCAL 7 FLDNR CAL 7 1980 BSM ALTHA WEST (1993) USFL CALHOUN DB07 CNF MNONE NONE DEFINED FLDNR 1980 FLDNR 1980 P0000NCD0058K1980 SCFLDNR FLORIDA DEPARTMENT OF NATURAL RESOURCES P0000DESCRIBED BY FL DEPT OF NAT RES 1980 3.0 MI SSW FROM ALTHA. BEGIN AT THE U.S. POST OFFICE IN ALTHA, PROCEED 3.0 MILES SOUTH ALONG STATE HIGHWAY 71 TO THE JUNCTION OF COUNTY ROAD C 275 AND THE MARK. THE MARK BEARS 62.2 FEET WEST-SOUTHWEST OF HIGHWAY 71 CENTERLINE, 59.1 FEET NORTH-NORTHWEST OF C 275 CENTERLINE, 35.7 FEET WEST OF THE FACE OF A CONCRETE CULVERT HEADWALL, AND 4.5 FEET EAST OF A WITNESS POST. THE MARK IS ABOVE LEVEL WITH HIGHWAY. LN303145 W0850759 S83 M 50.435 M A88 199106 21
