BackForwardInstrument:  ETM+ 

Instrument details
Acronym ETM+
Full name Enhanced Thematic Mapper +
Purpose Land and vegetation observation
Short description 8 channels (6 narrow-band in VIS/NIR/SWIR, one PAN,  one in TIR) [see detailed characteristics below]
Background Evolution of ETM flown on Landsat-6
Scanning Technique Wiskbroom; 6000 pixel/line (narrow-band), 12000 pixel/line (PAN), 3000 pixel/line (TIR); swath 185 km
Resolution 30 m (6 narrow-band channels), 15 m (PAN), 60 m (TIR)
Coverage / Cycle Global coverage in 16 days, in daylight.
Mass 441 kg Power 590 W Data Rate 150 Mbps

 

Providing Agency NASA
Instrument Maturity Flown on operational programme
Utilization Period: 1999 to 2024
Last update: 2021-06-16
Detailed characteristics
Central Spectral SNR or NEΔT @ specified input
wavelength interval Low signal High signal
Panchromatic 0.50 - 0.90 µm 14 @ 22.9 W m-2 sr-1 μm-1 80 @ 156.3 W m-2 sr-1 μm-1
0.48 µm 0.45 - 0.52 µm 36 @ 40 W m-2 sr-1 μm-1 130 @ 190 W m-2 sr-1 μm-1
0.56 µm 0.53 - 0.61 µm 37 @ 30 W m-2 sr-1 μm-1 167 @ 193.7 W m-2 sr-1 μm-1
0.66 µm 0.63 - 0.69 µm 24 @ 21.7 W m-2 sr-1 μm-1 127  @ 149.6 W m-2 sr-1 μm-1
0.83 µm 0.78 - 0.90 µm 33 @ 13.6 W m-2 sr-1 μm-1 226 @ 149.6 W m-2 sr-1 μm-1
1.65 µm 1.55 - 1.75 µm 34 @ 4.0 W m-2 sr-1 μm-1 176 @ 31.5 W m-2 sr-1 μm-1
2.20 µm 2.09 - 2.35 µm 27 @ 1.7 W m-2 sr-1 μm-1 130 @ 11.1 W m-2 sr-1 μm-1
11.45 µm 10.4 - 12.5 µm 0.2 K @ 300 K 0.2 K @ 320K
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
  • High resolution optical imager
WIGOS Subcomponents
  • Subcomponent 1
  • High-resolution multi-spectral VIS/IR imagers
  • High-resolution multi-spectral VIS/IR imager
Mission objectives
Primary mission objectives
  • Biomass
  • Fire fractional cover
  • Fraction of Absorbed PAR (FAPAR)
  • Fraction of vegetated land
  • Land cover
  • Leaf Area Index (LAI)
  • Normalised Difference Vegetation Index (NDVI)
  • Vegetation type
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
Biomass*4 - fairCloud sensitive.. Index only.. Infrequent coverage.. Daylight only.VIS, NIR and SWIR channels. Biomass inferred from NDVI and LAI
Cloud cover2 - very highInfrequent coverage.Channels in VIS, NIR, SWIR and the TIR window around 11 micrometers
Cloud optical depth3 - highLow-density cloud only.. Infrequent coverage.. Daylight only.VIS, NIR and SWIR channels
Cloud top temperature5 - marginalInfrequent coverage.TIR window channel(s) around 11 micrometers
Cloud type2 - very highInfrequent coverage.Channels in VIS, NIR, SWIR and the TIR window around 11 micrometers
Earth surface albedo5 - marginalCloud sensitive.. Infrequent coverage.VIS channels
Fire fractional cover*1 - primaryCloud sensitive.. Infrequent coverage.VIS and TIR channels
Fire radiative power5 - marginalCloud sensitive.. Infrequent coverage.TIR window channel(s) around 11 micrometers
Fire temperature5 - marginalCloud sensitive.. Infrequent coverage.TIR window channel(s) around 11 micrometers
Fraction of Absorbed PAR (FAPAR)*4 - fairCloud sensitive.. Infrequent coverage.VIS channels including Red at 700 nm
Fraction of vegetated land*1 - primaryCloud sensitive.. Daylight only.VIS, NIR and SWIR channels
Glacier cover3 - highCloud sensitive.. Long time for mapping.. Daylight only.VIS, NIR, SWIR and panchromatic channels for accurate boundary detection and screening ice from clouds
Land cover*1 - primaryCloud sensitive.. Daylight only.VIS, NIR and SWIR channels
Leaf Area Index (LAI)*2 - very highCloud sensitive.. Daylight only.. Infrequent coverage.VIS, NIR and SWIR channels
Normalised Difference Vegetation Index (NDVI)*2 - very highCloud sensitive.. Infrequent coverage.VIS and NIR channels
Photosynthetically Active Radiation (PAR)4 - fairCloud sensitive.. Infrequent coverage.VIS channels, range undersampled
Sea surface temperature5 - marginalCloud sensitive.. Infrequent coverage.TIR window channel(s)
Short-wave cloud reflectance4 - fairInfrequent coverage.VIS, NIR and SWIR channels. Unsuitable dynamic range (saturation)
Snow cover1 - primaryCloud sensitive.. Infrequent coverage.. Daylight only.VIS, NIR, SWIR (snow/cloud discrimination) and panchromatic (higher resolution) channels
Soil moisture at surface4 - fairCloud sensitive.. Index only.. Infrequent coverage.VIS and TIR window channels. Soil moisture inferred from thermal inertia
Soil type1 - primaryCloud sensitive.. Daylight only.VIS, NIR and SWIR channels
Upward short-wave irradiance at TOA5 - marginalSpectral interpolation needed.. Information on BRDF needed.. Infrequent coverage.VIS, NIR and SWIR channels
Vegetation type*2 - very highCloud sensitive.. Daylight only.VIS, NIR and SWIR channels
Aerosol volcanic ash5 - marginalCloud sensitive.. Infrequent coverage.. Daylight only.VIS, NIR and SWIR channels
Aerosol volcanic ash Total Column5 - marginalCloud sensitive.. Infrequent coverage.. Daylight only.VIS, NIR and SWIR channels
Sea-ice cover2 - very highCloud sensitive.VIS, NIR (for contour enhancement), SWIR (for discrimination from clouds) and TIR channels