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Lorre, J.

Publications and source records attributed to Lorre, J..

9 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Planetary Topography Map Generation

The planetary community is particularly challenged in pursuing digital elevation model generation due to: (1) limited multi-look observations and (2) the dynamic nature of the observation which introduces complex geometeric relationships between observed body, spacecraft position, and sensor orientation.

surface topography↗
NASA NTRS1979

Some properties of the knots in the M87 jet

Photographs taken in 1956 by Baade show the knots in the jet of M87 to be polarized. In 1978, these plates were repeated under conditions as identical as possible. A careful comparison indicates that the polarization and intensity of the knots have changed in the 22 year interval. Emission lines in the nucleus of M87 not previously seen have been revealed by extensive 5 m SIT spectroscopy. The same spectroscopy with galaxy subtracted, however, has failed to reveal any features in the jet. The known optical and radio properties of the jet are reviewed. A coincidence is found in almost all of the defining properties of BL Lacertae objects with the properties of the knots in the jet. Statistical studies of the distribution of BL Lacertae objects near bright galaxies reveals a marginally significant excess of such associations.

Sulentic, J. W.↗
NASA NTRS1976

Image processing of galaxy photographs

New computer techniques for analyzing and processing photographic images of galaxies are presented, with interesting scientific findings gleaned from the processed photographic data. Discovery and enhancement of very faint and low-contrast nebulous features, improved resolution of near-limit detail in nebulous and stellar images, and relative colors of a group of nebulosities in the field are attained by the methods. Digital algorithms, nonlinear pattern-recognition filters, linear convolution filters, plate averaging and contrast enhancement techniques, and an atmospheric deconvolution technique are described. New detail is revealed in images of NGC 7331, Stephan's Quintet, Seyfert's Sextet, and the jet in M87, via processes of addition of plates, star removal, contrast enhancement, standard deviation filtering, and computer ratioing to bring out qualitative color differences.

Arp, H.↗