Download presentation

Presentation is loading. Please wait.

Published byCiera Virgin Modified over 2 years ago

1
1 Sat07_73.ppt, 2007-10-23. GPS Definition. Precise satellite navigation-system, which after 1993 will give users a 3-D position and velocity as well as a precise time anywhere on and in the vicinity of the Earth

2
2 Sat07_73.ppt, 2007-10-23. GPS /

3
3 3 SEGMENTS: Space-segment Control-segment User-segment

4
4 Sat07_73.ppt, 2007-10-23. GPS, Configuration /

5
5 Sat07_73.ppt, 2007-10-23. GPS Constallation 18 satellites and 4 reserve in 6 planes Lifetime: 7.5 years 6 planes, 60 0 separated Inclination: 55 0 Semimajor axis: 26000 km Period: 11 hours 58 min

6
6 Sat07_73.ppt, 2007-10-23. Satellitbaner GPS, i= 55 0.

7
7 Sat07_73.ppt, 2007-10-23. GPS satellite

8
8

9
9 Sat07_73.ppt, 2007-10-23. GPS, Observation principle

10
10 Sat07_73.ppt, 2007-10-23. GPS signal

11
11 Sat07_73.ppt, 2007-10-23. GPS position and velocity determination.

12
12 Sat07_73.ppt, 2007-10-23. GPS signal

13
13 Sat07_73.ppt, 2007-10-23. GPS Signal (II) L1: 154 x 10.23 MHz = 1.57542 GHz L2: 120 x 10.23 MHz = 1.22760 GPz Whar is the wave-length ? Modulated with P-Code: 10.23 MHz = ca. 30 m, Repeated after 266 days = 7 days for 1 satellite Zero at 0.0 UT Saturday/sunday Only L1 modulated with C/A code: 1.023 MHz = Ca. 300 m

14
14 Sat07_73.ppt, 2007-10-23. Satellite-orbits– orbit changes. 16 parameters, Updated every hour

15
15 Sat07_73.ppt, 2007-10-23. Satellite orbit parameters for GPS Mean-anomali Mean-anomaly change Excentricity Square-root semimajor axis Rectacensionen Inclination at t 0e Perigæums argument Tidsændring af rectac. Time-change of i Corection of f+ Correction of r Reference-time /

16
16 Sat07_73.ppt, 2007-10-23. Satellite orbit error - relative positioning Influence of orbit-error on position determination Reduced if we determine difference-vector Relativ precision: db/b dr (m) b(km) db 1 ppm 20 10 1cm 0.1 ppm 2 10 0.1 100 1

17
17 Sat07_73.ppt, 2007-10-23. GPS, error-sources.

18
18 Sat07_73.ppt, 2007-10-23. Differentiel GPS

19
19 Sat07_73.ppt, 2007-10-23. GPS, position-error.

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google