Engineering topics
Martin, J. M.
Publications and source records attributed to Martin, J. M..
Source Regions of the Slow Solar Wind
While the fast solar wind is generally thought to originate from coronal holes, the source of the slow solar wind is only known to be associated with the highly structured and highly variable streamer belt.
An Automated Mapping Processor Using C-Band Interferometric SAR Data
We present the description of a processor which has been implemented to generate map products starting from C-band interferometric data. The first stage of the processor consists of the conventional interferometric SAR processing producing a Digital Elevation Model (DEMs) and a SAR brightness image in sensor coordinates.
An Automated Mapping Processor using C-Band Interferometric SAR Data
We describe a processor which has been implemented to generate map products starting from C-band interferometric data. The first stage of the processor consists of the conventional interferometric synthetic aperture radar (SAR) processing producing a digital elevation model (DEM) and a SAR brightness image in sensor coordinates. In the second stage of processing, a land use classification map is obtained by using the DEM, brightness, and interferometric correlation layers. Auxiliary layers which include a drainage layer, a height gradient layer, a height error layer, an estimated penetration layer, and a shaded relief layer are also computed. In the final step, all UTM collocated layers are combined in a geographical information system (GIS) which allows for both hard copy map products and digital applications.
An Automated Mapping Processor Using C-Band Interferometric SAR Data
We present the description of a processor which has been implemented to generate map products starting from C-band interferometric data. The first stage of the processor consists of the conventional interferometric SAR processing producing a Digital Elevation Model (DEMs) and a SAR brightness image in sensor coordinates. In the second stage of processing, a land use classification map is obtained by using the DEM, brightness, and interferometric correlation layers. Auxiliary layers which include a drainage layer, a height gradient layer, a height error layer, an estimated penetration layer, and a shaded relief layer are also computed. In the final step, all UTM collocated layers are combined in a GIS system which allows for both hard copy map products and for digital applications.
A Fast Algorithm for Altimeter Waveform Retracking with Appications to the Geosat Altimeter
In this paper, we present a new technique for faster than real time estimation for height from altimeter waveforms using modest computer resources.
Assessment of the Topex Altimeter Performance Using Waveform Retracking
In order to assess the accuracy of the TOPEX altimeter data, we have reprocessed the raw altimeter waveform data using more sophisticated algorithms than those implemented in the altimeter hardware.
Estimation of of the Electromagnetic Bias from Retracked TOPEX Data
We examine the EM bias by using retracked TOPEX altimeter data.
Theory and design of interferometric synthetic aperture radars
A derivation of the signal statistics, an optimal estimator of the interferometric phase, and the expression necessary to calculate the height-error budget are presented. These expressions are used to derive methods of optimizing the parameters of the interferometric synthetic aperture radar system (InSAR), and are then employed in a specific design example for a system to perform high-resolution global topographic mapping with a one-year mission lifetime, subject to current technological constraints. A Monte Carlo simulation of this InSAR system is performed to evaluate its performance for realistic topography. The results indicate that this system has the potential to satisfy the stringent accuracy and resolution requirements for geophysical use of global topographic data.
Extragalactic OH megamasers in strong IRAS sources
From the OH and HI survey of the strongest far infrared IRAS sources, 3 new powerful OH megamasers were discovered in Arp 143, IRAS 1510+0724 and in the uncatalogued IRAS source, IRAS 17208-0014. The HI line, the OH 1667 and 1665 MHz main lines and the 21 cm continuum observations were made with Nancy radio telescope. The optical spectra and images were obtained at the European Southern Observatory. The spectra are displayed in figures together with the main IR and OH properties of the 8 megamasers detected up to now, including IC 4553, NGC 3690 and Mrk 231, Mrk 273 and III ZW35.
A search for the radio occultation flash at Jupiter
A focusing effect, the evolute flash, on Jupiter was sought in radio data obtained by Voyager 1 using a modified matched-filter technique. Several peaks at the 8 standard deviation level were present in the filter output, although they were separated by times up to 3.3 s and could not be identified as the flash. A lower bound on the absorption along a ray with periapsis near the 4 bar level was established at 25 dB. It is estimated that the flash would have been detected if the distance behind the planet where the spacecraft trajectory crossed the evolute were at least 20 Jupiter radii, as compared to near 7 radii in the experiment.
Mammotropic and somatotropic hormones in sera of normal rats and in rats bearing primary and grafted pituitary tumors
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