satellite climatology - orbits geostationary orbits sun synchroneous orbits precessing orbit...

24
Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Upload: felix-townsend

Post on 19-Jan-2018

241 views

Category:

Documents


0 download

DESCRIPTION

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

TRANSCRIPT

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

Satellite Climatology - Orbits

Geostationary orbitsSun synchroneous orbitsPrecessing orbitDiscussion

Page 2: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Inclination

inclination

satellite orbit

perigee

plane of satellite orbit

equatorial plane

Page 3: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

BasicsSatellites in circular orbitsattractive force Fg = m g (R/r)²centrifugal force Fc = m r ²m: mass of the satelliteR: radius of the earth (R = 6370 km)r: distance to the center of the earthg: acceleration of gravity (g = 9.81 m/s²): angular velocity ( = 2 f, f: rotation frequency)Stable orbitFg = Fc r=3 gR2

2πf 2

Page 4: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Satellite period and orbits

10 20 30 40 x106 m

24

20

16

12

8

4

radius

satellite period [h]velocity [ x1000 km/h]

synchronous distance35,786 km

Page 5: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Different Orbital Distances

Page 6: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

1. geostationary orbit

Page 7: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion
Page 8: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion
Page 9: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Geostationary Geostationary OrbitOrbit

Page 10: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Geostationary Orbiting SatellitesGeostationary Orbiting Satellites

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

Page 11: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

2. Low sun synchroneous orbit

Page 12: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion
Page 13: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Polar Orbiting SatellitesPolar Orbiting Satellites

Satellite observes globe in “swaths”Satellite observes globe in “swaths”700-1700km from Earth’s surface700-1700km from Earth’s surface

Page 14: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Polar OrbitPolar Orbit

Page 15: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Polar Orbiting SatellitesPolar Orbiting Satellites

Page 16: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

(Near) Polar Orbiting Satellites

Page 17: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Daily Coverage

Page 18: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

3. Precessing orbit

Page 19: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Orbits shown in inertial space and size relative to Earth is correct

Other orbits

Page 20: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

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?

Page 21: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Worldwide Operational Weather Worldwide Operational Weather Satellite ObservingSatellite Observing

Page 22: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Polar RegionsThe 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.

Page 23: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Satellite Constellation

A group of electronic satellites working in concert is known as a satellite constellation. 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.

Page 24: Satellite Climatology - Orbits Geostationary orbits Sun synchroneous orbits Precessing orbit Discussion

Satellite Formation