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Tropospheric Emission Spectrometer (TES)

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About TES

TES is a high-resolution infrared-imaging Fourier transform spectrometer offers a line-width-limited discrimination of essentially all radiatively active molecular species in the Earth's lower atmosphere.

TES has significantly more the spectral resolution of the AIRS instrument being flown aboard EOS Aqua. TES employs both the natural thermal emission of the surface and atmosphere and reflected sunlight, thereby providing day-night coverage anywhere on the globe.

TES operates in a combination of limb and nadir mode (called global survey mode) every other. On alternate days, TES does special observations including "step and stare" mode and assessment of special targets like volcanoes.

Farewell to a Pioneering Pollution Sensor

On Jan. 31, NASA ended the Tropospheric Emission Spectrometer's (TES) almost 14-year career of discovery. Launched in 2004 on NASA's Aura spacecraft, TES was the first instrument designed to monitor ozone in the lowest layers of the atmosphere directly from space. Its high-resolution observations led to new measurements of atmospheric gases that have altered our understanding of the Earth system. [Go to Feature]

TES Parameters

Maximum sampling time of 16 sec , signal-to-noise ratio of 600:1



Limb mode:
Altitude coverage = 0-34 km
Nadir and limb viewing
(fully targetable)
Spectral region:
3.2 to 15.4 μm , with four single-line arrays optimized for different spectral regions
5.3 x 8.5 km
Spatial resolution:
0.53 x 5.3 km
385 kg (allocation)
Duty cycle:
334W (allocation)
Data rate:
6.2 Mbps (peak); 4.9 Mbps (average)
Thermal control by:
2 Stirling cycle coolers, heater, radiators
Thermal operating range:
0-30¡ C FOV: +45¡ to -72¡ along-track, ±45¡ cross-track
Instrument IFOV:
12 x 7.5 mrad

Pointing requirements (platform+instrument, 3s):

156 arcsec (pitch)
124 arcsec
156 arcsec (over 50 sec )
Physical size:
140 x 130 x 135 cm (stowed); 304 x 130 x 135 cm (deployed)
TES instrument decommissioned

TES collected spectral "signatures," illustrated here, of ozone and other gases in the lower atmosphere. Credit: NASA

Key Facts

  • TES Generates three-dimensional profiles on a global scale of virtually all infrared-active species from Earth's surface to the lower stratosphere
  • Measurements of gradients of many tropospheric species in order to understand troposphere-stratosphere exchange;
  • Determination of long-term trends in radiative active minor constituents in the lower atmosphere to investigate effects on global radiative balance and atmospheric dynamics.