CRISTA-NF - a Helium-cooled Infrared Telescope for the Atmosphere

The technical Realization

CRISTA-NF utilizes two grating spectrometers simultaneously to measure the infrared radiation of atmospheric trace gases using 15 infrared detectors. The telescope  holds a turnable primary mirror which is aligned to the respective altitude by the electronics control system.

The complete optics is housed in a cryostat which provides the necessary operating temperature of about - 260 oC. The cryostat holds a Helium tank with a maximum capacity of 125 Liter which accounts for 60 hours of hold time.

An ample electronics monitors and controls the instruments and records scientific data. A unique position control system calculates the exact roll position and adjusts the primary mirror accordingly.

Additional details are provided in the following list of technical data:

 Length 1910 mm
 Diameter of Vacuum Shell
850 mm
 Weight 360 kg
 Volume of Helium Tank
125 l
 Telescope Herschel-Telescope (120 mm)
 Altitude Range
5 - 20 km
 Vertical Resolution 200 -300 m
 Pointing Accuracy

+/- 30 arc min
+/- 30 arc sec
 Spectrometer 2 Ebert-Fastie Spectrometers
 Spectral Resolution

 Time per Spectrum 1 s
 Time per altitude profile
1 min

Integration concept for GEOPHYSICA Bay 1


Herschel-Telescope with two grating spectrometers

CRISTA-NF Elektronics

Test of the new control system