BackForwardInstrument:  MISR 

Instrument details
Acronym MISR
Full name Multi-angle Imaging Spectro-Radiometer
Purpose Aerosol properties, cloud properties, cloud/aerosol motion wind vectors, Earth's surface Bidirectional Reflectance Distribution Function (BRDF)
Short description

Assembly of 9 cameras at different forward, nadir and aft viewing angles, each camera having 4 spectral VIS/NIR channels, for a total of 36 channels [see detailed characteristics below]

For more information, see here
Background

MISR is one of the first multi-angle, multispectral space-based imagers.
Scanning Technique

Along track, the nine cameras have the following viewing angles: nadir, ± 26.1°, ± 45.6°, ± 60.0° and ± 70.5°. Cross-track : pushbroom scanning, each camera has 4 line arrays of 1504 active pixels, one array for each spectral band, swath about 380 km.
Resolution 250 m for the nadir-pointing camera, 275 m for the 8 off-nadir pointing cameras. In Global Observing mode, for the off-nadir cameras, only the red channel is acquired at full resolution, the remaining
Coverage / Cycle Near-global coverage in one week, in daylight. Global coverage in 9 days.
Mass 148 kg Power 131 W Data Rate 3.3 Mbps

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2000 to 2026
Last update: 2024-09-30
Detailed characteristics
Central wavelength Bandwidth SNR @ specified input spectral radiance
446.4 nm 41.9 nm  300 @ 179 W m-2 sr-1 μm-1
557.5 nm 28.6 nm  620 @ 177 W m-2 sr-1 μm-1
671.7 nm 21.9 nm  650 @ 146 W m-2 sr-1 μm-1
866.4 nm 39.7 nm  740 @   93 W m-2 sr-1 μm-1
Radiometric accuracy: 3% at maximum signal
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Earth observation instrument
  • Passive optical radiometer or spectrometer
  • Moderate resolution optical imager
WIGOS Subcomponents
  • Subcomponent 2
  • Multi-angle, multi-polarization radiometers
  • Multi-angle, multi-polarization radiometer
Mission objectives
Primary mission objectives
  • Cloud optical depth
  • Earth surface albedo
  • Earth surface short-wave bidirectional reflectance
  • Short-wave cloud reflectance
  • Wind (horizontal)
Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Biomass5 - marginalCloud sensitive.. Index only.. Daylight only.VIS and NIR channels. Biomass inferred from NDVI
Cloud cover5 - marginalDaylight only.VIS and NIR channels
Cloud drop effective radius4 - fairAt cloud top.. Daylight only.VIS and NIR channels and different viewing angles (for differentiation).
Cloud ice effective radius4 - fairAt cloud top.. Daylight only.VIS and NIR channels with different viewing angles (for differentiation).
Cloud optical depth*4 - fairLow-density cloud only.. Daylight only.VIS and NIR channels with different viewing angles
Cloud type5 - marginalDaylight only.VIS and NIR channels viewing under more angles
Downward short-wave irradiance at Earth surface5 - marginalCloud sensitive.. Highly indirect.VIS and NIR channels
Earth surface albedo*1 - primaryCloud sensitive.VIS channels with many viewing angles to account for anisotropic reflectivity
Earth surface short-wave bidirectional reflectance*2 - very highCloud sensitive.VIS and NIR range with many different viewing angles
Fire fractional cover5 - marginalCloud sensitive.. Coarse spatial resolution.. Daylight only.VIS channels
Fraction of Absorbed PAR (FAPAR)1 - primaryCloud sensitive.VIS channels including Red at 700 nm, with more viewing angles
Leaf Area Index (LAI)4 - fairCloud sensitive.. Daylight only.VIS and NIR channels. LAI inferred from NDVI
Normalised Difference Vegetation Index (NDVI)3 - highCloud sensitive.VIS and NIR channels
Photosynthetically Active Radiation (PAR)1 - primaryCloud sensitive.VIS channels, range undersampled; multi-viewing capability for irradiance reconstruction
Sea-ice cover5 - marginalCloud sensitive.. Daylight only.VIS and NIR (for contour enhancement) channels
Short-wave cloud reflectance*2 - very highNo specific limitation.VIS and NIR channels with multi-viewing capability to account for anisotropical reflectance
Snow cover4 - fairCloud sensitive.. Daylight only.VIS and NIR channels
Soil moisture at surface5 - marginalCloud sensitive.. Index only.. Daylight only.VIS and NIR channels. Soil moisture inferred from differential brightness
Upward short-wave irradiance at TOA4 - fairSpectral interpolation needed.VIS and NIR channels with multi-viewing capability to account for anisotropical reflectance
Aerosol volcanic ash1 - primaryCloud sensitive.. Daylight only.VIS and NIR channels viewing under many different angles
Aerosol volcanic ash Total Column1 - primaryCloud sensitive.. Daylight only.VIS and NIR channels with many different viewing angles
Wind (horizontal)*4 - fairCloud or water vapour tracers needed.. Daylight only.VIS channel(s) viewing under many different angles to infer cloud motion and geometric height estimate