1. Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

2. Inclination inclination   satellite orbit perigee plane of satellite orbit equatorial plane

3. Basics Satellites in circular orbits attractive force F g = m g (R/r)² centrifugal force F c = m r  ² m: mass of the satellite R: radius of the earth (R = 6370 km) r: distance to the center of the earth g: acceleration of gravity (g = 9.81 m/s²)  : angular velocity (  = 2  f, f: rotation frequency) Stable orbit F g = F c

4. Satellite period and orbits 10203040 x10 6 m 24 20 16 12 8 4 radius satellite period [h] velocity [ x1000 km/h] synchronous distance 35,786 km

5. Different Orbital Distances

6. 1. geostationary orbit

9. Geostationary Orbit

10. Geostationary Orbiting Satellites Satellite observes same area at all times. Continuous sampling. 36000km from Earth’s surface!

11. 2. Low sun synchroneous orbit

13. Polar Orbiting Satellites Satellite observes globe in “swaths” 700-1700km from Earth’s surface

14. Polar Orbit

15. Polar Orbiting Satellites

16. (Near) Polar Orbiting Satellites

17. Daily Coverage

18. 3. Precessing orbit

19. Orbits shown in inertial space and size relative to Earth is correct Other orbits

20. Discussion: what's the effect of orbit on: Science: Viewing zenith angles? Revisit time? Diurnal cycle? Coverage? Tropics/polar regions? Sun glint? Technical: Data transmission? Data reception? Solar panel? Instruments optics? Space weather? Debris? Orbital drift?

21. Worldwide Operational Weather Satellite Observing

22. Polar Regions The satellite doesn't pass directly over the pole due to the slight inclination of the orbital plane. The transparent overlay identifies the 3000 km wide swath that is viewed by the AVHRR imaging instrument on the satellite. The yellow curves delineate the limits of the 60 degree viewing arcs from the six "standard" geostationary satellites included in these discussions.

23. Satellite Constellation A group of electronic satellites working in concert is known as a satellite constellation.electronicsatellites Such a constellation can be considered to be a number of satellites with coordinated ground coverage, operating together under shared control, synchronised so that they overlap well in coverage and complement rather than interfere with other satellites' coverage.coverageinterfere

24. Satellite Formation