Using CORS Workshop (Continuously Operating Reference Stations)

11/14/01


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Table of Contents

Using CORS Workshop (Continuously Operating Reference Stations)

CORS Information

Global Positioning System GPS

GPS Satellite

GPS Receivers

Standalone Positioning: Since May 1, 2000

Pseudorange From Code Data

Standalone Positioning: By 2011

GPS Error Sources

Atmospheric Delays

Signal Multipath

Differential GPS Positioning

Real Time Kinematic: Today

Real Time Kinematic: Tomorrow

National CORS Accuracy

Continuously Operating Reference Stations

Regional CORS Coverage

Local CORS Coverage

CORS Sites

CORS Overview

CORS Overview-Continued

Cooperative CORS

National CORS & Cooperative CORS

CORS Sites near Houston, TX

National CORS Partners

CORS Partners: Federal

CORS Partners: States

CORS Partners: Scientific

CORS Partners: International

Civil GPS Use

Consumer/Recreational

Future GPS Users

Higer Accuracy Examples

Timing Applications

CORS Applications

Height Modernization

Geographic Information Systems (GIS)

LIDAR images of Manhattan before and after 11 SEP 2001

DGPS & NDGPS Coverage

Sites With "MET" Sensors

Monitoring Precipitable Water Vapor

Mapping Total Electron Content (TEC)

Monitoring Crustal Motion

Knowing Where You Are!

National Spatial Reference System

A geodetic reference framework forms the spatial foundation for the creation of any Land-Information System (LIS).”

National Spatial Reference System

Improving Positional Accuracy

High Accuracy Reference Networks

NAD 83 Readjustment

NAD 83 Readjustment

CORS Advantages

CORS Data Quality

CORS Disadvantages

CORS Density and Position Redundancy

Non-Differential GPS (Autonomous or Stand-alone)

Differential GPS

Real-Time Differential GPS

Variations on GPS Positioning

Continuously Operating Reference Stations

Three Tests for Positioning Precision

Test Design: dual-frequency carrier phase

Baselines Used In Accuracy Tests

RMS versus Distance

RMS versus Time Carrier-Phase (North)

RMS versus Time Carrier-Phase (East)

RMS versus Time Carrier-Phase (Up)

Positioning Accuracy Using CORS

National CORS Accuracy

Multiple Sessions (North) twice the rms (cm)

Multiple Sessions (East) twice the rms (cm)

Comments

Test Design: Single-Frequency Code

Precision Relative to Baseline Length GPS Code (North)

Precision Relative to Baseline Length Code (East)

Multiple Sessions (North) twice the rms (m)

Multiple Sessions (East) twice the rms (m)

Comments

Maritime/Nationwide DGPS

Overall Summary

Surveying Applications Using CORS

Surveying Applications Using CORS

Surveying Applications Using CORS

Surveying Applications Using CORS

Accessing CORS Data & Metadata

CORS Web page

CORS Coverage

Sampling Rates

Detail Map

Metadata for a CORS Site

CORS Position & Velocity (NAD 83)

CORS Position & Velocity (ITRF)

CORS Data Availability and Profile

CORS Data Availability...con't

CORS Site Photo

Position Time Series (Long Term)

Position Time Series (Last 60 Days)

Station Log File

Station Log File, Con't

Station Log File, Con't

Station Log File, Con't

Primary Data FileS

GPS Data Files -- RINEX Format v2.10

How Does NGS Collect CORS Data?

RINEX File Naming Conventions

RINEX File Naming Conventions, Con't

Meteorological Data

NGS Satellite Emphemerides

Three ways to download CORS Information

CORS Home Page

UFCORS - Page 1

UFCORS - Page 2

UFCORS - Standard Download Page

Access To CORS ArchivE Via FTP

FTP

FTP Directory Structure

What is OPUS?

How does OPUS work?

How do I use OPUS?

OPUS Home Page

How is the antenna height measured?

Why do I need antenna type?

What does OPUS output look like?

How are OPUS positions computed?

How are OPUS errors estimated?

How would I get Help?

What are some OPUS guidelines?

GPS Antenna Phase Center Variation

GPS Antenna Phase Pattern Calibrations

Antenna Calibration Facility in Corbin, VA

Phase Center Variation

File Compression Format

Software / RINEX Utilities

Utility Examples

Utility Examples, Con't

Estimated Cost For CORS Equipment

Guidelines For Setting a CORS Monument

Guidelines for Constructing a CORS Antenna Mount

Guidelines for Constructing a CORS Antenna Mount - continued

Defining a ECEF Reference System

3-D ECEF Coordinates

North American Datum of 1983 (NAD 83)

North American Datum of 1983 (NAD 83) (continued)

World Geodetic System of 1984 (WGS 84)

Tracking Network Defining WGS 84

International Terrestrial Reference Frame (ITRF)

International Terrestrial Reference Frame (ITRF) - (continued)

Sites Defining ITRF96

ITRF Horizontal Velocities

Simplified Concept of ITRF 97 vs. NAD 83

Effect of Rotation About the Y-axis

Reference Frame Transformation

Transformation Parameters ITRF96 to NAD_83

Transforming Positions

GPS vs. Leveling

GEOID99, the Link

Future Directions of the National CORS

Future Directions of the National CORS (continued)

GPS Modernization

Global Navigation Satellite Systems (GNSS)

Author: Ron Travis

Email: Richard.Snay@noaa.gov

CORS Home Page: http://www.ngs.noaa.gov/CORS/