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ODE: Mars


Mission: MGS


PDS Geosciences Node: PDS Source Information


Instrument: TES


TES Data Node Page


The Mars Global Surveyor’s Thermal Emission Spectrometer (TES).  The TES instrument uses a Michelson interferometer to make infrared spectrometric measurements, and uses two sets of broad-band bolometric detectors to cover the thermal and visible bands. Eachof the three bands has a co-aligned array of 6 detectors arranged in a 3x2 configuration and each detector has a field ofview of 8.3 mrad square.


In normal operation the TES completes a scan of the Michelson mirror every 2 seconds and each of the spectrometer detectors measures the spectral radiance of the target at 143 wavelengths with 10-wavenumber spacing. The visual and thermal bolometers integrate during the entire scan and produce one measurement per detector. This 2-second scan is called a "single length"scan.


The TES has a second operating mode in which the Michelson mirror is scanned twice as far over a 4-second period. This mode is referred to as a "double length" scan and produces 286 spectral points with 5 - wavenumber spacing for each of the spectrometer detectors. During double scans the two bolometric channels integrate twice as long, but still produce onlya single value per detector.


The instrument also contains software to optionally perform spectral, spatial, and temporal averaging of the spectrometer data. None of these post-processing steps are applied to the bolometric data.


The TES has a rotating pointing mirror that allows the instrument to take measurements ranging from the nadir position up to and past the planet's limb in both the fore and aft directions.  Additionally, the pointing mirror can be positioned to take measurements of space and of the  internal reference surfaces and lamps contained within the body of the TES instrument.


The TES Standard Data Product contains the raw and calibrated thermal IR radiance spectra, the visual and thermal bolometric radiance measurements, and several atmospheric and surface properties derived from this data. Also included are the parameters that describe each observation, some downlinked diagnostic information, and the derived pointing and positional information calculated from the project's SPICE kernels.

TES  Products:



Data Set


Time Sequential Data Products.  Each TES-TSDR Product consists of up to ten product elements stored in separate files.

For more information see the TES Product Software Interface Specification (SIS), TES Archive Software Interface Specification (SIS) and catalog files



Thermal Inertial Maps.

For more information see the TES Geosciences Data Page,, TES TIMAP Readme, TES Web Site and catalog files