Topic 4: Altimetry Flashcards
Altimeter
uses time delay relationship to range distance with great accuracy
measure surface topography
spaceborne altimeter have:
satellites
Nadir facing censor
orbit system
data processing system
two types of Altimeters
Radar and Laser
what is ICESat
a satellite laser altimeter that was used to measure ice
what two variables are required to measure altimetry
Time and range
what are two other measurements for altimetry
- intensity, called backscatter
- waveform. complex and difficult to interpret
what is footprint
the coverage a satellite has over the ground.
error sources of Altimetry
- satellite position
- atmospheric effects
- deriving true-height from a radar waveform.
how is sea level determined
With altimetry
two contributors to SLR
- thermal expansion
- freshwater addition
what is the current largest contributor to SLR right now
small melting terrestrial glaciers
ice sheets and sea ice are measured with what remote sensing device
Altimetry
ICESat -2
- Laser Altimeter
- raw data
- gridded surface height
how is sea ice thickness measured
Its only estimated, using archimedes principle. its measure using Altimetry
what is freeboard
freeboard is the amount of ice that is above the surface of water. must be floating
