Weeks 5-7 Flashcards
pros of satellite platforms
covers larger area, collects imagery on a systematic and repetitive basis, systematic geometric distortions
cons of satellite platform
restricted to collect certain areas during a specific time, more difficult to fix/repair a sensor
pros of aircraft platform
flexible schedule and revisit time, high and variable spatial resolutions
cons of aircraft platform
covers a smaller area, more sources of geometric distortions
active vs passive sensors
passive - source of energy is either the sun or the earth
active - source of energy is in remote sensor
what are some applications of multispectral platforms?
vegetation disturbance, water monitoring, tracking lake ice coverage
what impacts emissivity?
color, surface roughness, moisture content, field of view, compaction, wavelength, and viewing angle
what are a few applications of thermal imaging?
wildlife monitoring, heat fluxes, soil moisture variation
what do passive microwaves detect and convert it to?
microwave energy which all natural surfaces emit, they convert this to brightness temperature
pros to passive microwave remote sensing
penetrates clouds, partially penetrates vegetation and soil, absorbed by vegetation, independent of solar radiation
cons to passive microwave remote sensing
larger field of view means lower spatial resolution, emissivity is subject to change, polar orbiting satellites provide discontinuous temporal coverage of equatorial regions
how do passive microwaves interact with soil?
temp of soil decreases brightness temperature
how do passive microwaves interact with snow?
there is more scattering, so brightness temperature is lowered
how do passive microwaves interact with ice?
ice increases the brightness temperature (younger ice has higher emissivity)
what are the 3 different styles of orbits?
geostationary - constant relative position over equator
near-polar - passes above or nearly above both poles
sun-synchronous - keeps pace with sun’s westward progress
