NASA 1998 SBIR Phase I


PROPOSAL NUMBER: 98-1 13.04-0003

PROJECT TITLE: Zenith Viewing Spectroradiometer for O3, SO2, NO2, Aerosol Optical Depths and UltraViolet Spectral Radiances (7008-490)

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

A zenith viewing spectroradiometer aircraft instrument is proposed for tropospheric profile measurements of O3, NO2, and SO2, aerosol optical depths and UV spectral radiances from differential column amounts measured as functions of aircraft altitude. The basic instrument consists of a temperature insensitive 0.125 m tandem Ebert-Fastie double monochromator scanning the wavelength range of 290 to 445 nm, 0.3 nm bandpass, which uses a Hamamatsu photon counting system as a detector. A nine-channel spectroradiometer uses nine narrow band ultrastable interference filters fabricated with the ion-assisted-deposition process for the wavelength range of 305 to 442 nm. The multifilter spectroradiometer is also used as a calibration transfer standard spectroradiometer for the scanning Ebert-Fastie double monochromator. A scanning linear variable filter (LVF) spectroradiometer operating in the range 300 to 400 nm will be evaluated as a low-cost lightweight alternative to the scanning double monochromator. The LVF was also fabricated with the IAD process by Barr Associates. A major objective of the proposed effort is to validate the accuracy of the zenith measurements of column amounts and aerosol optical depths against the conventional Langley type direct sun measurements.

POTENTIAL COMMERCIAL APPLICATIONS

The potential commercial applications of this proposed aircraft instrument are for providing a validation of tropospheric ozone and aerosols, SO2 and NO2 in areas of regional pollution for validation of satellite overpass measurements over various types of land surfaces. It also has applications as a regional pollution monitoring instrument if good linear variable filters can be fabricated using the IAD process. Other commercial applications are its use as a calibrator transfer standard spectroradiometer for surface radiation monitoring instruments in the field.

NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR

Donald Heath
Reserach Support Instruments
5500 Central Ave., Suite 202
Boulder , CO 80301

NAME AND ADDRESS OF OFFEROR

Research Support Instruments
4325B Forbes Blvd.
Lanham , MD 20706