Engineering topics

Decker, J. A., Jr.

Publications and source records attributed to Decker, J. A., Jr..

2 records

NASA NTRS1976

Hadamard transform imager and imaging spectrometer

An imager and a spectrometric imager, which achieve multiplexing by the use of binary optical encoding masks, have been built and tested. The masks are based on orthogonal, pseudorandom digital codes derived from Hadamard matrices. The spatial (and/or spectral) data are therefore obtained in the form of a Hadamard transform of the spatial (and/or spectral) scene. Computer algorithms are used to decode the data and reconstruct images of the original scene. The hardware, algorithms processing and display facility are described. A number of spatial and spatial/spectral images, obtained in the laboratory, are presented.

Swift, R. D.↗

NASA NTRS1973

High altitude infrared spectroscopic evidence for bound water on Mars.

The reflectivity of the Martian surface has been measured between 2.0 and 4.0 microns. A broad absorption band is observed which has a minimum at 2.85 microns. The position and shape of the band is compared to features in numerous terrestrial minerals. Bound water in the Martian surface material is the most likely cause of the observed band. The strength of the observed band suggests a bound water content of approximately 1% by weight. The band is inconsistent with more than a few % limonite or hydrated polymeric carbon suboxide. A mean particle radius of about 100 microns is deduced. The quality of bound water derived has a range of geological, climatic, and exobiological implications.

Houck, J. R.↗