Geodesy with the Global Positioning System

EESC G9945 Section 2

Spring Term 2013

Jim Davis & Meredith Nettles

Term Project

The goal of the project is to write a program (in any computer language with which you are comfortable) to analyze the pseudorange from files containing raw GPS data and broadcast ephemerides (both in RINEX format) and estimate using least-squares a position for the GPS site.

Input to program: (1) the name of the RINEX data file and (2) the name of the RINEX orbit file
Output from the program: (1) Cartesian coordinates of the site in the WGS-84 system and RMS residual
Data type to be used: Ionosphere-free psuedorange

The program may be written by the individual student, or students may form groups of up to three. To facilitate completion of the project, there are sereval sub-goals. These sub-goals will parallel the information in the classes. The sub-goals and deadlines are:

Jan 30: e-mail Jim Davis the names of group members
Feb 22: Write subroutine(s) that will read in the broadcast ephemerides and return the Cartesian coordinates for all the satellites the epoch closest to an epoch that will be specified [more info]
Mar 08: Using the results from the previous sub-goal, write subroutines that return the Cartesian coordinates for all the satellites for any epoch during the day. [more info]
Mar 29: Read the GPS observation file and write out a list of epochs, the list of satellites observed at each epoch, and the ionosphere-free pseudorange observation for each satellite observed at each epoch. [more info]
May 03: Using the routines from the previous sub-goals, complete the program that reads all the data and estimates, using standard least-squares, the site position [more info]

This page will be updated with more information.


The data set we'll use was collected on day 100 of 2008 and can be obtained here. The broadcast ephemeris can be obtained from the IGS