Present and Future Global Navigation Satellite Systems (GNSS)
GEO2TECDI_GPS_2.pdf
GEO2TECDI_GPS_2.pdf
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Principle of <strong>Satellite</strong> navigation<br />
<strong>Satellite</strong> transmits:<br />
• Time code (atomic clock) *)<br />
• Message with position <strong>and</strong><br />
satellite clock error<br />
<strong>Satellite</strong><br />
Receiver computes:<br />
• time difference between<br />
satellite <strong>and</strong> receiver clock <br />
pseudo range<br />
• coordinates receiver (3) <strong>and</strong><br />
receiver clock error (1) **)<br />
x s<br />
p s r<br />
e s r<br />
x r<br />
c dt r<br />
3<br />
Receiver<br />
*) GPS<br />
• 1 civilian signal (L1-C/A)<br />
• 2 military signals L1-P(Y), L2-P(Y)<br />
**) From 4 or more satellites<br />
Earth<br />
GEO2TECDI – Bangkok, May, 2009 – <strong>GNSS</strong> Lecture 2
Change language