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Blume, H. J. C.

Publications and source records attributed to Blume, H. J. C..

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Description, characteristics and testing of the NASA airborne radar

Presented here is a description of a coherent radar scattermeter and its associated signal processing hardware, which have been specifically designed to detect microbursts and record their radar characteristics. Radar parameters, signal processing techniques and detection algorithms, all under computer control, combine to sense and process reflectivity, clutter, and microburst data. Also presented is the system's high density, high data rate recording system. This digital system is capable of recording many minutes of the in-phase and quadrature components and corresponding receiver gains of the scattered returns for selected spatial regions, as well as other aircraft and hardware related parameters of interest for post-flight analysis. Information is given in viewgraph form.

Jones, W. R.↗
NASA NTRS1985

Development of UHF radiometer

A wideband multifrequency UHF radiometer was initially developed to operate in the 500 to 710 MHz frequency range for the remote measurement of ocean water salinity. However, radio-frequency interference required a reconfiguration to operate in the single-frequency radio astronomy band of 608 to 614 MHz. Details of the radiometer development and testing are described. Flight testing over variable terrain provided a performance comparison of the UHF radiometer with an L-band radiometer for remote sensing of geophysical parameters. Although theoretically more sensitive, the UHF radiometer was found to be less desirable in practice than the L-band radiometer.

Kendall, B. M.↗
NASA NTRS1985

Determination of Electromagnetic Properties of Mesh Material Using Advanced Radiometer Techniques

The need for a large diameter deployable antenna to map soil moisture with a 10 kilometer or better resolution using a microwave radiometer is discussed. A 6 meter deployable antenna is also needed to map sea surface temperature on the Navy Remote Ocean Sensor System (NROSS). Both of these deployable antennas require a mesh membrane material as the reflecting surface. The determination of the electromagnetic properties of mesh materials is a difficult problem. The Antenna and Microwave Research Branch (AMRB) of Langley Research Center was asked to measure the material to be used on MROSS by NRL. A cooperative program was initiated to measure this mesh material using two advanced radiometer techniques.

Arrington, R. F.↗
NASA NTRS1982

Measurement of losses of mesh membrane material for reflector applications with an S-band radiometer

The spatial resolution, the frequency of revisits, and the accuracy requirements for the detection of Earth surface parameters from space force the satellite designers to consider large space structures for microwaves. Some Earth surface parameters are only detectable with radiometers. Because the large reflectors should be much lighter than solid and deployable reflectors, mesh membrane material is considered to be used as the reflector. It is essential to determine the emissivity of the reflecting material even when close to zero to estimate the accuracy of the radiometer measurement. An existing S-band radiometer was used to determine the loss of a 1 sq m pretensioned mesh first in a field experiment and later in a well shielded laboratory set-up. The models for retrieving the emissivity of the mesh are described in detail and the equivalent losses for different mesh positions were calculated.

Blume, H. J. C.↗
NASA NTRS1977

Microwave radiometric measurements of sea-surface parameters

A technique to remotely measure sea-surface temperature and salinity (for concentrations greater than 5 parts-per-thousand) with accuracies of 1 C and 1 part-per-thousand, respectively, was demonstrated with a two-frequency microwave radiometer system.

Kendall, B. M.↗