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4. Summary
IPC VfJ Part 3: Contributions to Symposium
An sunphotometer mstrument has been designed and construeted using photodiode array and aberration
corrected concave holographic grating technology. The instrument is speeifieally designed -to be handheld, use
little power and accurately measure the concentrations of trace constituents in the atmosphere. Preliminary tests
using a early prototype confirm that NOg can b% identißed with the resoiution necessary to measure optical
depths and its verticai distribution when using solar occültation techniques from space. Further Software and
hardware developments are antieipated with coneurrent increases in the resolving power of the spectrometer.
A final yersion of the instrument is expeeted to fly ä NASA Shuttle in mid-1992 as a mid-deck cabin experiment.
6. Relerences
1. Talmi, Y, änd R.W. Simpson, Apphed Optics, 19,1401 (1980).
2. Simpson, R.W., Rey. Sei. Instrum., 50, 730 (1979).
3. Cunningham, LA. and A. Fenster, Med. Phys,, 11, 303 (1984).
4. McGeorge, S.W. and E.D, Salin, Spectrochimica Acta, 40B, 435 (1985).
5. Vogt, S.S., RG. Tull and P Kelton, Apphed Optics, 17, 574 (1978).
6. Walker, G.A.H., R. Johnson and S. Yang, Adv. Elec. Electron Phys. 64A, 213 (1985).
7. Mayes, P.M. and J B. Callis, Apphed Spect. 43, 27 (1989).
7. Figure Captions
Figure 1. Schematic diagram of the sunphotospectrometer optical layout.
Figure 2. A comparison of transmission spectra for 0.01 cm NOg at a 1 nm resoiution. The Lambda 9
spectrometer data (solid) was obtained at a resoiution of 0.1 nm and degraded fo the resoiution
of the sunphotospectrometer (dashed).
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