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Intensified all-sky camera


Instrument P.I.: Peter Jenniskens, SETI Institute.


The information below will be updated as more precise data is received.

Technique: Wide field intensified camera with all-sky lens.

Scientific objective: To measure the total radiative output of the SRC during entry in the 400 - 900 nm band.

Instrument: Part of INT system. This camera consists of a 15 mm f2.8 Canon lens, an XX1332 image intensifier with large 48-mm photocathode, and a Sony handycam camcorder (recording of video output on Hi-8 tape in NTSC format - 640 x 480 pixels). The field of view is about 160 when mounted so that the dome does not obstruct. Moonlight is blocked by covering the zenith part of the dome.

Heritage: This camera was flown before to record meteors. Same setup.

Aircraft hardware requirements: Fixed mount. Electricity at window. Optional: operation on batteries.

Allsky

Instrument validation tests: This cameras was flown before for near-real time flux measurements of meteor storms during the 2002 Leonid MAC mission when a bright Moon was at about 38 degree elevation (see picture above).

Sensitivity: With a 160 degree field of view in long axis of camera (left-right on aircraft) and 124 degree in short axis (front-aft), the star limiting magnitude is about +3.0 magnitude, somewhat less with Moonlight. 2002 Leonid MAC mission record has lmiting magnitude about +2.0. Here, we will choose 160 fov in short axis (front-aft), further lowering the limiting magnitude to about +1.

Dynamic range: 8-bit (factor 256).

Frame rate and exposure times: 30 frames per second, 60 fields (odd, even, interlaced) per second. Exposure time is nearly 1/60s per field.

Spectral resolution - gives the FWHM of an instrument-broadened unresolved atomic spectral line:
none

Relative spectral response - gives the wavelength dependence of the intensifier. The Quantum Efficiency of the system depends somewhat on the angle of viewing through the window (near-UV cut-off) and the choice of objective grating:

INT response curve

wavelength:  Radiant sensitivity: 
   (nm)       (micro A/lm)
	
380	5.000
390	6.000
400	7.200
410	8.500
420	11.000
430	14.000
440	19.500
450	21.798
460	23.878
470	25.771
480	27.492
490	29.051
500	30.462
510	31.736
520	32.883
530	33.912
540	34.832
550	35.650
560	36.374
570	37.010
580	37.563
590	38.037
600	38.436
610	38.763
620	39.019
630	39.207
640	39.325
650	39.375
660	39.353
670	39.258
680	39.088
690	38.837
700	38.502
710	38.077
720	37.555
730	36.929
740	36.192
750	35.334
760	34.346
770	33.217
780	31.936
790	30.491
800	28.868
810	27.054
820	25.034
830	22.792
840	20.313
850	17.579
860	14.520
870	10.000
880	5.500
890	4.000