Satellites

resolution

resolving power

spatial, spectral, radiometric, temporal

what are the four types of resolution?

spatial resolution

practically effective measure for the (theoretical) geometric resolving power of a sensor

spectral resolution

a measure of the width of a spectral band or channel; also, the “granularity” with which a senor divides its spectral coverage into discretely observable parts

spectral coverage

that portion of the spectrum which a sensor detects

spectral band

a well-defined continuous range (interval) of wavelengths in the electromagnetic spectrum individually sensed by a detector

Full Width at Half Maximum

what does FWHM stand for?

500 nm

what’s 0.5 micrometers in nanometers?

0.3 micrometers

what’s 300 nm in micrometers?

100 nm

the spectral resolution starts at 0.7 micrometers and ends at 0.8 micrometers. What is the bandwidth of the FWHM?

200 nm

the spectral resolution starts at 0.4 micrometers and ends at 0.6 micrometers. What is the bandwidth of the FWHM?

0.4 micrometers to 0.7 micrometers

what is the range of black and white film in micrometers?

0.4 micrometers to 0.5 micrometers

what is the range of blue in color film?

0.5 micrometers to 0.6 micrometers

what is the range of green in color film?

0.6 micrometers to 0.7 micrometers

what is the range of red in color film?

Visible and Near-Infrared

what does VNIR stand for?

Shortwave Infrared

what does SWIR stand for?

Thermal Infrared

what does TIR stand for?

Advanced Spaceborne Thermal Emission and Reflection Radiometer

what does ASTER stand for?

14

how many distinct spectral bands are featured on ASTER?

Enhanced Thematic Mapper

what does ETM stand for?

Thematic Mapper (TM)

the imaging sensor design used on Landsat 4 and Landsat 5

radiometric resolution

how sensitive a sensor is to differences in the energy, or brightness levels

quantization

in radiometric resolution, the range of voltage is referred to as _____

Digital Number (DN)

the raw, uncalibrated integer value recorded by a remote sensing sensor for a single pixel in a specific spectral band

0-255

DN for 8-bit

0-511

DN for 9-bit

0-1023

DN for 10-bit

2^Q

Total DN =

2^Q - 1

Max DN Value =

number of quantization/bit

What does ‘Q’ represent in terms of radiometric resolution?

64

what is the total DN of a 6-bit?

how many unique values

what does the total DN tell us?

127

what is the max DN of 7-bit?

temporal resolution

how frequently repetitive coverage of an area can be obtained in imagery

16 days

what is the temporal resolution of Landsat?

Moderate Resolution Imaging Spectroradiometer

what does MODIS stand for?

1-2 days

what is the temporal resolution of MODIS?

swath width

the strip of the Earth's surface that a remote sensing sensor captures during a single pass

nadir

swath width is typically measured or specified at _____ where the strip is narrowest and most geometrically sharp

smaller

the greater the swath width, the ____ the resolution

greater

the smaller the swath width, the ____ the resolution

large swath widths

do satellites with small or large swath widths tend use fewer orbits?

Advanced Very High Resolution Radiometer

what does AVHRR stand for?

250m, 500m, 1000m

spatial resolution of AVHRR/MODIS

2048 km swath

swath width of AVHRR/MODIS

global coverage, 2 days

temporal resolution of AVHRR/MODIS

Multi-Angle Imaging SpectroRadiometer

what does MISR stand for?

275m, 550m, 1100m

spatial resolution of MISR

360 km

swath width of MISR

global coverage, 9 days

temporal resolution of MISR

15m, 30m

spatial resolution of Landsat

183 km

swath width of Landsat

16 day orbital repeat

temporal resolution of Landsat

seasonal global coverage

what is a unique attribute of Landsat’s temporal resolution?

15m, 30m, 90m

spatial resolution of ASTER

60 km

swath width of ASTER

45-60 day orbital repeat

temporal resolution of ASTER

1m, 5m

spatial resolution of commercial systems

10 km

swath width of commercial systems

decades

how long does global coverage take for commercial systems?

active satellite

satellite uses own source of energy

passive satellite

satellite depends on solar energy

microwave

RADAR source of energy

optical

LIDAR source of energy

visible light, infrared

the two categories of passive optical energy sources

near, shortwave, thermal

the three categories of infrared

geostationary, sun-synchronous

what are the two orbit characteristics of satellites?

push broom, whisk broom

what are the two sensor types for satellites?

low, medium, high

the three levels of spatial resolution

geostationary satellite

Earth-orbiting satellite, revolves in the same direction the earth rotates (west to east)

35800 km

altitude of a geostationary satellite

24 hours

how long does one orbit take on a geostationary satellite?

40%

coverage of Earth’s surface with a single geostationary satellite

3

how many geostationary satellites can provide full coverage of the Earth?

120 degrees of longitude

how far separated do three geostationary satellites have to be for full Earth coverage?

Geostationary Operational Environmental Satellite

what does GOES stand for?

Meteorological Satellite

what does METEOSTAT stand for?

geostationary

what orbit characteristics are telephone and television relay satellites?

geostationary

what orbit characteristic is GOES?

geostationary

what orbit characteristic is METEOSTAT?

NASA and NOAA

what two organizations launched GOES?

sun-synchronous satellites

operates in the orbit that provides consistent lighting of the Earth-scan view, passes the equator and each latitude at the same time each day

sun-synchronous

what orbit category are the majority of operating optical satellites?

push broom sensor

a technology for obtaining satellite images with optical cameras that moves in a row-by-row motion

perpendicular

in a push broom sensor, a line of sensors are arranged ______ to the flight direction of the spacecraft is used

looks at a specific area for a longer time

why does a push broom sensor gather more light than a whisk broom sensor?

passive

what type of energy source uses a push broom satellite?

whisk broom sensor

a technology for obtaining satellite images with optical cameras which goes one-by-one

passive

what type of energy source utilizes whisk broom sensors?

one pixel

in a whiskbroom sensor, a mirror scans across the satellite’s path (ground track), reflecting light into a single detector which collects data ____ at a time

moving parts

what makes the whisk broom sensor expensive and more prone to wearing out?

wide

whisk broom sensors have a _____ swath width

narrow

push broom sensors have a _____ swath width

complex

whisk broom sensors have _____ mechanical systems

simple

push broom sensors have _____ mechanical systems

simple

whisk broom sensors have _____ optical systems

complex

push broom sensors have _____ optical systems

filters and sensors

what do whisk broom sensors utilize mechanically?

Charge-Coupled Device

what does CCD stand for?