Engineering topics
Publications and source records attributed to Freeman, T..
One of the greatest costs of any spaceborne mission is the total instrument mass. For SAR, one third of the mass is typically related to the antenna strucure, whose elevation and azimuth dimensions are used to increase the signal to noise ration as well as to reduce the presence of spurious signals.
The National Space Development Agency of Japan's (NASDA) JERS-1 SAR began collecting data in 1995 for the Global Rain Forest Mapping Project (GRFM). The GRFM data quality has been examined for products resulting from both the NASDA and Alaska SAR facility's (ASF) processing facilities.
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This paper describes the work being performed under the auspices of the HPCC/ESS Grand Challenge Applications and Enabling Scaleable Computing Testbed applied to advancing computing technology to SAR interferometry and imaging science.
An in situ measuring technique for use in automated composite processing and quality control is discussed. Frequency dependent electromagnetic sensors are used to measure processing parameters at four ply positions inside a thick section 192-ply graphite-epoxy composite during cure in an 8 x 4 in. autoclave. Viscosity measurements obtained using the sensors are compared with the viscosities calculated using the Loos-Springer cure process model. Good overall agreement is obtained. In a subsequent autoclave run, the output from the four sensors was used to control the autoclave temperature. Using the 'closed loop' sensor controlled autoclave temperature resulted in a more uniform and more rapid cure cycle.