Engineering topics

Pelzmann, R. F., Jr.

Publications and source records attributed to Pelzmann, R. F., Jr..

4 records

NASA NTRS1978

Data processing in infrared astronomy

Infrared astronomy is often carried out with rocket probes or orbiting satellite telescopes in order to escape the effects of atmospheric absorption. The data returned from such missions is a highly abstracted digital representation of measurements made by analog detectors. The ability to extract infrared-emission information from these data streams depends on a thorough understanding of the information flow from the telescope aperture to the computer center. This paper reviews the primary elements of this end-to-end concept and the impact of each of these elements on the data processing algorithms, including the division between onboard and ground processing for scientific measurements.

Pelzmann, R. F., Jr.↗

NASA NTRS1977

Point source detection in infrared astronomical surveys

Data processing techniques useful for infrared astronomy data analysis systems are reported. This investigation is restricted to consideration of data from space-based telescope systems operating as survey instruments. In this report the theoretical background for specific point-source detection schemes is completed, and the development of specific algorithms and software for the broad range of requirements is begun.

Pelzmann, R. F., Jr.↗

NASA NTRS1976

Efficient computer algorithms for infrared astronomy data processing

Data processing techniques to be studied for use in infrared astronomy data analysis systems are outlined. Only data from space based telescope systems operating as survey instruments are considered. Resulting algorithms, and in some cases specific software, will be applicable for use with the infrared astronomy satellite (IRAS) and the shuttle infrared telescope facility (SIRTF). Operational tests made during the investigation use data from the celestial mapping program (CMP). The overall task differs from that involved in ground-based infrared telescope data reduction.

Pelzmann, R. F., Jr.↗

NASA NTRS1974

Infrared maser emission from interstellar hydroxyl molecules

The energy structure and transition rates of the OH radical were studied in rotational and vibrational energies to provide the basis for studies of the population distributions under various exciting mechanisms. The absorption of ultra-violet or near infrared radiation which might explain the microwave emission was examined, as well as the absorption of low temperature blackbody radiation and collisions with molecular hydrogen. The results of the population studies were applied to the transfer equation, and a model of a uniform spherical cloud of OH was used with the pumping process which occurs uniformly throughout the region. The emission is unsaturated and the intensity is an exponential function of the size of the cloud for high pumping rates, and the region of unsaturated emission shrinks for lower pumping rates until the entire region is saturated, the intensity then becoming a linear function of the size of the emitting cloud.

Pelzmann, R. F., Jr.↗