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pages.skl
pages input file controlling the models and constaints used in the solution
Overview
The pages.skl file contains those model and constraint controls
which rarely change. pages.skl is a required control file
for pages. pages.skl is an ASCII file and, therefore,
easily modifiable with an editor.
A basic pages.skl file contains two sections:
- model control,
- constraint control.
Each section will be described in detail below but some general rules are:
- Only one model control section is permitted,
- The model control entries must appear in the order shown,
- The model control entries should be included,
- The constraint controls are entered using a descriptive line or
identifier, or an identifier and value,
- Any file name may include the path,
- The default path is always the current directory,
- The maximum length of a file name plus path is 64 characters,
- All characters to the right of a dollar sign, "$", are ignored,
- Lines starting with a dollar sign are skipped,
- Blanks are not significant except in names including constraint
identifier names,
- Control flags are not case sensitive. However, file and site names, and
constraint identifiers are case sensitive.
Model Control Section
Example: Example
Line number
0 $ Diagnostics ( 1)
900 $ Screen Output Interval [sec] ( 2)
30 $ Observation Interval [sec] ( 3)
15 $ Elevation Cutoff [deg] ( 4)
540 $ Data Gap [sec] ( 5)
1.0E-01 $ Edit Limit [m] ( 6)
0 $ Tropo Model ( 7)
1 1 $ TSF Flags ( 8)
7200 7200 $ TSF Max & Min Times [sec] ( 9)
1 90 $ TSF Elv Bin Number & Limits [deg] (10)
0 $ TSF Min Obs Number (11)
0 0 0 0 $ PM & LOD Flags (12)
86400 $ PM & LOD Time [sec] (13)
../files/site_info $ Station Info File (14)
$ Satellite Info File (15)
$ Descriptive Text File (16)
$ Pole File (17)
$ UT1 File (18)
$ Broadcast Orbit File (19)
phscor $ Antenna phase corrections (20)
END (21)
Following is a detailed explanation of each line of the Model
Control Section of the pages.skl file:
Line 1.
0 $ Diagnostics
The diagnostic flag controls the amount of information pages
tells the user about its actions. The larger the number, the
more information is output. The most common settings are:
0 = minimum info
1 = post-fit residual plots
2 = a priori and post-fit residual plots
This flag is potentially dangerous because of the large
quantities of printed output which could be generated.
Line 2.
900 $ Screen Output Interval [sec]
The screen output interval flag controls how frequently pages
confirms its operation by writing the current data time to the
screen. Units are in seconds. In the example, messages appear on
the screen after each five minutes of data are processed.
Line 3.
30 $ Observation Interval [sec]
The observation interval flag controls how much data are used.
Units are in seconds. For example, data may be recorded and
edited using a 30-second interval, but processed by pages using
a 120-second interval. The shorter interval would have advantages
for data editing, but be unnecessary for a satisfactory final
solution.
Line 4.
15 $ Elevation Cutoff [deg]
The elevation cutoff flag governs the minimum elevation an
observation must be to be processed in pages.
Line 5.
540 $ Data Gap [sec]
A gap in the data implies a discontinuity or cycle slip. The
data gap flag specifies the minimum significant gap size in seconds.
A new phase ambiguity for a baseline-satellite combination will be
estimated automatically if a gap in the satellite's tracking is
longer than this interval (and no integer bias has been given).
Line 6.
1.0E-01 $ Edit Limit [m]
Because pages has the capability to identify outliers and issue
edit instructions to delete such data points, this parameter will
set the limit, in meters, beyond which a point is designated as
an outlier.
Lines 7 - 11
0 $ Tropo Model
1 1 $ TSF Flags
7200 7200 $ TSF Max & Min Times [sec]
1 90 $ TSF Elv Bin Number & Limits [deg]
0 $ TSF Min Obs Number
The above five lines control the tropospheric model, the estimation
type, and the interval. The first line of the five identifies the
tropospheric model to use. Three options are available:
0 = the NMF mapping functions with Saastemoinen dry and wet tropo
models (default);
1 = the CfA 2.2 mapping functions with Saastemoinen dry and wet
tropo models;
2 = tropo model included in the database. Currently this is the
Marini model.
Line 8 contains two flags controlling the manner in which the
tropo corrections are to be estimated. A "0" for both flags instructs
pages not to estimate tropo corrections. This overrides any instructions
in the pages.inp file. A "1" in the first position causes pages to
estimate constant, additive, wet tropo corrections for the stations
designated in the pages.inp file. A "1" in the second position causes
a piecewise-linear, continuous wet tropo correction to be estimated
regardless of the value of the first parameter.
Line 9 sets the duration of the estimated tropo correction. Two
numbers appear on this line. Both values are used in current
research. In normal operation both values must be identical. The units
are in seconds.
Lines 10 and 11 are reserved for research and should be left at:
1 90
0
respectively.
Lines 12 - 13
0 0 0 0 $ PM & LOD Flags
86400 $ PM & LOD Time [sec]
The two lines above control the estimation of Earth orientation
parameters (EOP). Line 12 controls which EOP are estimated and how.
The four values actually are two pairs of values. The first pair
controls the X and Y pole estimate, while the second pair controls
the UT1 estimate. As with the tropospheric parameters, a "0" means
no estimation should occur. A "1" in the first position of each
pair instructs the program to estimate additive, constant corrections.
A "1" in the second position of each pair causes a piecewise-linear
continuous estimation.
Line 13 sets the frequency at which these EOP corrections are
estimated. Units are in seconds. This limit applies to all EOP
parameter estimates.
Line 14.
../files/site_info $ Station Info File
Defines an input file name for A-priori station information.
Line 15.
$ Satellite Info File
In the current pages configuration, this line 15 is defunct.
Line 16.
$ Descriptive Text File
In the current pages configuration, this line 16 is defunct.
Line 17.
$ Pole File
This file contains A-priori information defining the X,Y pole values.
The X and Y pole file must be named "pole." with no path and
therefore must reside in the current directory, if named.
Line 18.
$ UT1 File
The UT1 file must be named "ut1." with no path and therefore
must reside in the current directory, if named.
Line 19.
$ Broadcast Orbit File
Self-explanatory.
Line 20.
phscor $ Antenna Phase Corrections
Line 21.
END
This line marks the end of the Model Control Section
Constraint Control Section
Because the constraint control identifiers can appear in any order,
the various possible identifiers will be listed alphabetically with
their descriptions and examples, where necessary. The case, spelling
and spacing of these identifiers is significant. This section name
is somewhat misleading because many types of parameters can be entered
or flags set in this section. Ultimately, all parameterization,
including that described in the Model Control Section above, will be
included in this section.
The Constraint Control Section requires two identifiers regardless
of the inclusion of any other identifiers:
- OPTIONS
- This identifies the start of the Constraint Control Section.
- END_OPTS
- This identifies the end of the Constraint Control Section.
All other constraint identifiers are optional. Some require additional
information. These cases will be noted and described in detail including
FORTRAN format specifications.
Following is a list, in alphabetical order, of all current options
available for the Constraint Control Section of the pages.skl file:
AGENCY ID
The SP3 format requires a four-character ID for the agency which
created the file. The default, "NGS", can be overridden with this
identifier.
NOTE: requires additional input on next line.
The identifier is followed by a string.
FORMAT: (A)
APPLY DD CORRELATIONS
Double-differencing introduces undesireable correlations between satellites. These
correlations are not normally accounted for in the processing. This
identifier forces pages to include a de-correlation technique
which corrects for this effect.
AVG. SITE CONST
End is identified by END-AVSI
Constrains the centroid of a group of sites. Each site could
shift but the average of the coordinates must not.
NOTE: requires additional input on subsequent lines.
There are two possible options to apply with this constraint:
1. USE A-PRIORI VALUES
This option causes pages to use the centroid of the input
station coordinates in defining the constraint equations.
The next line must give a variance to be applied to the
constraint equation.
UNITS: meters squared
FORMAT: (13X, F16.6)
Immediately following the variance line are lines designating
the sites to be constrained, one line per site.
Example:
AVG. SITE CONST
USE A-PRIORI VALUES
1.0e-06
sant
mcmu
END-AVSI
2. If USE A-PRIORI VALUES is not specified,
then the variance line is followed by the lines designating the
sites to be constrained and the coordinates to use for defining
the centroid of those sites, one site per line.
UNITS: meters
FORMAT: (A12, 1X, 3F16.6)
Example:
AVG. SITE CONST
1.0e-06
sant 1769693.285393 -5044574.219096 -3468321.218509
mcmu -1310696.280131 310469.128906 -6213368.431436
END-AVSI
AVG. SITE VEL. CONST.
End is identified by END-SITE
Constrains the velocity centroid of a group of sites. Each site's
velocity could shift, but the average must not.
NOTE: requires additional input on subsequent lines.
The next line must define a constraint on either rotation or
translation, and both may be included, one immediately following the
other. These options are defined as follows:
ROTATION
Indicates a constraint on the rotation of the network, as defined by
the velocities of the constrained sites, plus three rotational velocity
components to be applied and a variance for the constraint.
UNITS: radians/year for velocity; (radians/year)squared for variance
FORMAT: (A12, 1X, 4F16.8)
TRANSLATION
Indicates a constraint on the translation of the network, as defined
by the velocities of the constrained sites, plus three velocity components
to be applied and a variance for the constraint.
UNITS: meters/year for velocity; (meters/year)squared for variance
FORMAT: (A12, 1X, 4F16.8)
Following these entries, the identifiers of the sites to be used in
the constraint are given, one entry per line.
Note that the velocity components defined in these constraints may
be zero, or can be computed from an a-priori velocity model for the
sites selected. To do so one must get the sum of the cross products
of the (A-priori velocity - Model velocity) times the coordinate
vector for the sites to be included.
Example:
AVG. SITE VEL. CONST.
TRANSLATION 0.000 0.000 0.000 1.000e-05
ROTATION 0.000 0.000 0.000 1.000e-05
sant
mcmu
END-SITE
COMMENTS
End is identified by END_COMM
Any remarks desired may be placed between these identifiers.
CONSTRAIN AVERAGE UT1
Constrains the average UT1 estimates.
NOTE: requires additional input on next line.
The identifier is followed by the standard deviation to be applied.
UNITS: seconds
FORMAT: free format
CONSTRAIN FIRST UT1
Constrains the first UT1 estimate.
NOTE: requires additional input on next line.
The identifier is followed by the standard deviation to be applied.
UNITS: seconds
FORMAT: free format
CONST. INDIVIDUAL SITE
End is identified by END-INDV-SITES
Constrains the coordinates of the indicated sites.
NOTE: requires additional input on subsequent lines.
There are two possible options to apply with this constraint:
1. USE A-PRIORI VALUES
This option causes pages to use the a-priori station
coordinates and sigmas to define the constraints. The
site ID's and an additional factor which is multiplied
times the weight to be applied to the constraints follow,
one entry per line.
UNITS: meters squared
FORMAT: (A12, 1X, E16.8)
Example:
CONST. INDIVIDUAL SITE
USE A-PRIORI VALUES
kokb 1.000e+00
algo 1.000e+00
madr 1.000e+00
END-INDV-SITES
2. Specify the site ID's, coordinates, and variances to be applied.
UNITS: meters for coordinates; meters squared for variance
FORMAT: (A12, 1X, 3F16.8, E16.8)
Example:
CONST. INDIVIDUAL SITE
sant 1769693.285393 -5044574.219096 -3468321.218509 1.000e-10
mcmu -1310696.280131 310469.128906 -6213368.431436 1.000e-10
END-INDV SITES
CONST. INDIVIDUAL VEL.
End is identified by END-INDV-VEL.
Constrains the indivdual sites' velocities.
NOTE: requires additional input on subsequent lines.
There are two possible options to apply with this constraint.
1. USE A-PRIORI VALUES
This option causes pages to use the input station velocities
and sigmas as constraints. The site ID's and an additional
factor which is multiplied times the weight to be applied to
the constraints follow, one entry per line.
UNITS: (meters/year)squared
FORMAT: (A12, 1X, E16.8)
Example:
CONST. INDIVIDUAL VEL.
USE A-PRIORI VALUES
kokb 1.000e+00
algo 1.000e+00
madr 1.000e+00
END-INDV-VEL.
2. Specify the site ID's, velocities, and variances to be applied.
UNITS: meters/year for velocities; (meters/year)squared for
variance.
FORMAT: (A12, 1X, 3F16.8, E16.8)
Example:
CONST. INDIVIDUAL VEL
sant 0.005 -0.007 0.002 1.000e-05
mcmu 0.110 -0.110 -0.103 1.000e-05
END-INDV-VEL.
DEFINE JUNCTION SITES
End is identified by END-JUNCT
Designates sites whose tropospheric corrections should be carried in
the global part of the matrix. This is necessary for sites
common in normal matrices to be joined into a combined adjustment
using the program gpscom.
NOTE: requires additional input on subsequent lines.
The site ID's are listed, one per line.
Example:
DEFINE JUNCTION SITES
sant
mcmu
END-JUNCT
EPOCH FOR OUTPUT
The coordinates of all sites are rotated to a common epoch on output.
The default is the start of the year the data were taken. This default
can be changed with this identifier.
NOTE: requires additional input on next line.
The identifier is followed on the next line by a date.
FORMAT: one of the following:
- year month day hour minute second
- year day-of-year hour minute second
- year month day
- year day-of-year
- modified Julian date
EQUAL VELOCITY PAIRS
End is identified by END-PAIR
This identifier forces pairs of sites to have the same velocity.
NOTE: requires additional input on subsequent lines.
The next line must give the variance to be applied as the constraint.
UNITS: (meters/year)squared
FORMAT: (13X, F16.8)
Subsequent lines contain two site ID's per line, designating the
site pairs to constrain.
FORMAT: (A12, 2X, A12)
Example:
EQUAL VELOCITY PAIRS
1.0e-07
gait gode
kosg brus
END-PAIR
FRAME ID
The SP3 format requires a five-character ID for the agency which
created the file. The default, "ITRF94", can be overridden with this
identifier.
NOTE: requires additional input on next line.
The identifier is followed by a string on the same line.
FORMAT: (15x,A)
HOLD APRIORI SCALE
Constrains the apriori scale of the reference frame. The sites used to
define this constraint are the same used in the list for either
identifier AVG. SITE CONST. or CONST. INDIVIDUAL SITE.
Constrains the adjustment such that the sites move
inwards or outwards from the center of the frame so that the
original scale is unchanged.
NOTE: requires additional input on next line.
The identifier is followed by the variance to be applied.
UNITS: (radians/year)squared
FORMAT: (13X, F16.8)
HOLD APRIORI VELOCITIES
Constrains all sites to their apriori velocities.
NOTE: requires additional input on next line.
The identifier is followed by the variance to be applied.
UNITS: (radians/year)squared
FORMAT: (13X, F16.8)
MAKE EOP GLOBAL
Indicates that EOP parameters are to appear in the global part
of the matrix.
MAKE SATELLITES GLOBAL
Indicates that satellite parameters are to appear in the global
part of the matrix.
NO SOLUTION
Forces pages to exit immediately after creating and writing the
normal matrix file.
NO XYZ ROTATION ABOUT X
Constrains the average rotation of the network as defined by the
computed coordinate shifts, about the X-axis. The sites used to
define this constraint are the same used in the list for either
identifier AVG. SITE CONST. or CONST. INDIVIDUAL SITE.
NOTE: requires additional input on next line.
The identifier is followed by the variance to be applied.
UNITS: (radians/year)squared
FORMAT: (13X, E16.8)
NO XYZ ROTATION ABOUT Y
Constrains the average rotation of the network as defined by the
computed coordinate shifts, about the Y-axis. The sites used to
define this constraint are the same used in the list for either
identifier AVG. SITE CONST. or CONST. INDIVIDUAL SITE.
NOTE: requires additional input on next line.
The identifier is followed by the variance to be applied.
UNITS: (radians/year)squared
FORMAT: (13X, E16.8)
NO XYZ ROTATION ABOUT Z
Constrains the average rotation of the network as defined by the
computed coordinate shifts, about the Z-axis. The sites used to
define this constraint are the same used in the list for either
identifier AVG. SITE CONST. or CONST. INDIVIDUAL SITE.
NOTE: requires additional input on next line.
The identifier is followed by the variance to be applied.
UNITS: (radians/year)squared
FORMAT: (13X, E16.8)
OBSERVATIONS STANDARD ERROR
The estimated error in the observable.
NOTE: requires additional input on next line.
The identifier is followed by the standard deviation to be applied.
UNITS: meters
FORMAT: (13X, F16.8)
OUTPUT INTEGER FILES
Instructs pages to create phase ambiguity (integer) files in the
standard format.
PROJECT NAME
The project name.
NOTE: requires additional input on next line.
FORMAT: (A72)
STATION INFO
Additional station information file names.
NOTE: requires additional input on next line.
The identifier is followed by a file name.
FORMAT: (A)
TIME FOR APRIORI VALUES
Occasionally, the coordinates for a site change, when the
reference frame is updated, for example. pages searches the
site information for the appropriate coordinates for the
date the data were taken. This identifier limits the search
effectively forcing sites to have consistent coordinates
through all processing. This is essential for long term
projects.
NOTE: requires additional input on next line.
The identifier is followed by a date.
FORMAT: one of the following:
- year month day hour minute second
- year day-of-year hour minute second
- year month day
- year day-of-year
- modified Julian date
TOLERANCE
The tolerance to singularities. LS matrix rows with Googe
numbers smaller than this value will be designated singular
and set to zero. When the tolerance is not specified in this
manner the value 1.0d-5 will be used as a default.
NOTE: requires a value on next line.
UNITS: dimensionless
FORMAT: (E10.3)
TROPO CONSTR
Constrains tropo estimate.
NOTE: requires additional input on next line.
The identifier is followed by the variance to be applied.
UNITS: (meters)squared
FORMAT: (13X, E16.8)
TURN OFF AVG. SITE X
Turns off the constraint on the average X coordinate for the
sites selected in identifier AVG. SITE CONST.
TURN OFF AVG. SITE Y
Turns off the constraint on the average Y coordinate for the
sites selected in identifier AVG. SITE CONST.
TURN OFF AVG. SITE Z
Turns off the constraint on the average Z coordinate for the
sites selected in identifier AVG. SITE CONST.
USE PHASE PATTERN OFFSETS
The IGS format antenna phase correction file contains the
appropriate offsets from the antenna reference point to the L1
and L2 phase centers. This identifier forces pages to use this
information. This is the default action of the program.
Alternatively, there is another constraint identifier which
will override this default action. This identifier is given as:
- DO NOT USE PHASE PATTERN OFFSETS
This identifier forces pages to ignore the information in the
IGS format antenna phase correction file regarding the offsets
from the antenna reference point to the L1 and L2 phase centers.
WRITE NORMAL MATRIX
Causes pages to create the normal matrix output file named
pag4.nrm. Several of these files for different data sets can then
be joined into a combined adjustment of the global parameters
using the program gpscom.
WRITE SINEX FILE
Causes pages to create the SINEX output file named pages.snx.
NOTE: requires additional input on subsequent lines.
This identifier requires the following information, one entry per line, in this exact order:
- DESCRIPTION
- description of the processing which produced this SINEX file;
- OUTPUT
- organization creating this file;
- CONTACT
- email address of person to contact with questions regarding this processing;
- SOFTWARE
- program name;
- HARDWARE
- system/hardware description;
- INPUT
- data source.
FORMAT: (A16, A)
XYZ ROTATION ABOUT CENTROID
Modifies the constraint for average rotation of the network, by
forcing the constraint to be defined with respect to the centroid
of the sites in the constraint rather than the origin of the
coordinate system.
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skl.html
March 2, 1998
Steve Hilla