satellite orbits n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Satellite Orbits PowerPoint Presentation
Download Presentation
Satellite Orbits

Loading in 2 Seconds...

play fullscreen
1 / 23

Satellite Orbits - PowerPoint PPT Presentation


  • 242 Views
  • Uploaded on

Satellite Orbits. Satellite Meteorology/Climatology Professor Menglin Jin. Satellite Orbits. At what location is the satellite looking? When is the satellite looking at a given location? How often is the satellite looking at a given location?

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Satellite Orbits' - Gabriel


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
satellite orbits

Satellite Orbits

Satellite Meteorology/Climatology

Professor Menglin Jin

satellite orbits1
Satellite Orbits
  • At what location is the satellite looking?
  • When is the satellite looking at a given location?
  • How often is the satellite looking at a given location?
  • At what angle is the satellite viewing a given location?
atmospheric remote sensing sensors satellite platforms and orbits
Atmospheric Remote Sensing Sensors, Satellite Platforms, and Orbits
  • Satellite orbits and platforms
    • Low Earth orbit
      • Sunsynchronous and repeat coverage
      • Precessing
    • Geosynchronous orbit
  • Sensor scanning modes
    • Whiskbroom and pushbroom scanners
    • Active and passive microwave radiometers
types of orbits
Types of orbits
  • Sunsynchronous orbits: An orbit in which the satellite passes every location at the same time each day
    • Noon satellites: pass over near noon and midnight
    • Morning satellites: pass over near dawn and dusk
    • Often referred to as “polar orbiters” because of the high latitudes they cross
    • Usually orbit within several hundred to a few thousand km from Earth
types of orbits1
Types of orbits
  • Geostationary (geosynchronous) orbits: An orbit which places the satellite above the same location at all times
    • Must be orbiting approximately 36,000 km above the Earth
    • Satellite can only “see” one hemisphere
low earth orbit concepts
Low Earth Orbit Concepts

Descending node

Ascending node

Perigee

Ground track

Orbit

Inclination angle

Equator

Orbit

South Pole

Apogee

sun synchronous polar orbit
Sun-Synchronous Polar Orbit

Earth Revolution

Equatorial illumination angle

Satellite Orbit

  • Satellite orbit precesses (retrograde)
    • 360° in one year
  • Maintains equatorial illumination angle constant throughout the year
    • ~10:30 AM in this example
timing of adjacent landsat 5 or 7 coverage tracks
Timing of Adjacent Landsat 5 or 7 Coverage Tracks

Adjacent swaths are imaged 7 days apart

tropical rainfall measuring mission orbit precessing
Tropical Rainfall Measuring Mission Orbit (Precessing)
  • A precessing low-inclination (35°), low-altitude (350 km) orbit to achieve high spatial resolution and capture the diurnal variation of tropical rainfall
    • Raised to 402 km in August 2001
trmm coverage
TRMM Coverage

1 day coverage

2 day coverage

definition of orbital period of a satellite
Definition of Orbital Period of a Satellite

The orbital period of a satellite around a planet is given by

where

T0 = orbital period (sec)

Rp = planet radius (6380 km for Earth)

H¢ = orbit altitude above planet’s surface (km)

gs = acceleration due to gravity (0.00981 km s-2 for Earth)

ellipse
Ellipse
  • An ellipse is defined as follows: For two given points, the foci, an ellipse is the locus of points such that the sum of the distance to each focus is constant.
  • BTW, Locus-A word for a set of points that forms a geometric figure or graph
kepler s laws
Kepler’s laws

1. Satellites follow an elliptical orbit with the Earth as one focus

Foci

Perigee

Apogee

period of orbit
Period of orbit

Period of orbit

42

T2= r3

  • Valid only for circular orbits (but a good approximation for most satellites)
  • Radius is measured from the center of the Earth (satellite altitude+Earth’s radius)
  • Accurate periods of elliptical orbits can be determined with Kepler’s Equation

Gme

Radius of the orbit

Gravitational constant

Mass of the Earth

space time sampling
Space-time sampling
  • Geostationary
    • Fixed (relatively) field of view
    • View area of about 42% of Earth’s surface
  • Sunsynchronous
    • Overlapping views
    • See each point at several viewing angles
  • Other orbits (“walking orbits”)
    • Passes each location at a different time of day
    • Earth Radiation Budget Satellite
    • Useful when dirunal information is needed
scanning techniques
Scanning techniques
  • Vidicom
    • Like television camera; “sees” everything at once
  • Swinging
    • Results in a zig-zag pattern of scanning
  • Spinning
    • Satellite spins in order to create image
  • Pushbroom
    • Multiple scanning elements, relies on forward motion of satellite