GPS Navigation Toolbox GNT08.1.2 (Scripts) Publisher's description
from moein mehrtash
In the past several years compact radio navigation receivers have proliferated in the civilian market place, generally under the name of GPS or Global Positioning System
In the past several years compact radio navigation receivers have proliferated in the civilian market place, generally under the name of GPS or Global Positioning System. Appearing as handheld units or built into cars, mobile phones, and airplanes, these commercial applications originated from a Cold War military application. GPS is a worldwide radio-navigation system formed from a constellation of 24 satellites, each in its own orbit 11,000 nautical miles above the Earth, and five ground stations that make sure the satellites are working properly. The GPS satellites each take 12 hours to orbit the Earth. Each GPS satellite continuously broadcasts a Navigation Message at 50 bit/s giving the time-of-day, GPS week number and satellite health information (all transmitted in the first part of the message), an ephemeris (transmitted in the second part of the message) and an almanac (later part of the message). The position calculated by a GPS receiver requires the current time, the position of the satellite and the measured delay of the received signal and then by using the triangulation rule the position of the receiver is determined. The large sources of error in GPS are produced by the atmospheric effect (ionospheric, tropospheric), clock errors of the satellite, multipath effect, satellite orbits errors and calculation-rounding errors. The errors of the GPS system are summarized in the following table. The individual values are no constant values, but are subject to variances. All numbers are approximate values
Table 1. Errors of GPS
Error Source Error
Ionospheric effects В± 5 meter
Shifts in the satellite orbits В± 2.5 meter
Clock errors of the satellites' clocks В± 2 meter
Multipath effect В± 1 meter
Tropospheric effects В± 0.5 meter
Calculation- und rounding errors В± 1 meter
This report include the review of
В• Principle of Radio Navigation: navigation base on trilateration has been investigated and the over determined Eq. for navigation has been solved.
В• GPS Ephemeris Data: for GPS navigation, the position of GPS satellite is very important so the by receiving ephemeris data the position of the satellite is determined.
В• GPS Errors: Three different sources of errors in GPS navigation has been investigated (Ionosphere, Troposphere and Satellite clock). Ionospheric Error model is generated base on Parkinson  and the Tropospheric Error Model based on Hopfiel model .
В• Simulation & GPS Toolbox: One of the targets of this work is generating Matlab GPS Toolbox and in one case study the performance of generated toolbox will be verified.
System Requirements:MATLAB 7.2 (R2006a)
Program Release Status: Major Update
Program Install Support: Install and Uninstall