wiki/THEMIS/457px-Themis-lg.jpg

THEMIS (THermal Emission Imaging System) is a multispectral imager allowing the analysis of the morphology, the composition and the physical properties of the Martian surface. It has 9 channels in the thermal infrared between 6.78μm and 14.88μm and 5 channels in the visible and near-infrared between 0.42μm and 0.86μm.

Data description

There are 3 types of THEMIS data: the infrared data, at 100 m/pixel, acquired by day and night, and the visible images, from 18 to 35 m/pixel (Christensen et al, 2004). The infrared images are approximately 30 km large and more than 100 km long on the surface and reached global coverage of the planet.

Data types Spatial Res. Number of Band Spectral Range
(TIR) THEMIS Infrared Day 100 m/pixel 10 6.78–14.88 μm
(TIR) THEMIS Infrared Night 100 m/pixel 10 6.78–14.88 μm

The nighttime’s images of THEMIS allow constraining the thermal inertia of the surface. Those images have a higher resolution than the TES pixels (100 m/pixel versus 3 km/pixel). It allows a more local analysis than with the TES dataset. The global coverage of the THEMIS dataset allows also a regional study at high resolution. Global maps acquired by night and day are available.

Only Infrared THEMIS data are available for download on MarsSI. The calibration pipeline is not yet available in MarsSI but will eventually be implemented when confidence in the product quality is deemed sufficient. For viewing convenience, the footprints coverage has been splitted in 4 categories:

  • THEMIS IR Day L: Long ground track during day time for infrared sensor
  • THEMIS IR Day S: Short ground track during day time for infrared sensor
  • THEMIS IR Night L: Long ground track during night time for infrared sensor
  • THEMIS IR Night S: Short ground track during night time for infrared sensor

Processing THEMIS data

References