Design specification for EOD-LARSYS/statistics and data transformation processors modification
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Two hardware aspects of the Mark 3 correlator are briefly described. The first area concerns the choice of interface to the controlling minicomputer and the second area concerns the implementation of the correlator module. Multiple computer automated measurement and control (CAMAC) modules and a single large CAMAC module were considered as possible packaging forms for the correlator. The large CAMAC module approach was chosen because of the difficulty in partitioning the correlator with minimum interconnections, the fabrication economy of a single large planar assembly, and the desire to minimize the number of modules.
There are no author-identified significant results in this report.
There are no author-identified significant results in this report.
The feasibility of real time digital processing of synthetic aperture radar data for Venus orbiting imaging radar low resolution modes was investigated. First, it is shown that range migration is not a problem for these modes. Then, under the assumption of no range migration, fast Fourier transform implementations for accomplishing both range and azimuth correlation in real time are shown to be feasible with current technology.
There are no author-identified significant results in this report.
The processing of plasma wave signals in spinning spacecraft in the range from D.C. to 500 Hz are described. Three antenna inputs were filtered to prevent aliasing above 500 Hz. A 92 db range of data was multiplexed to an analog to digital converter, and then to three RCA 1802 microcomputers.
The rationale for system development is given along with reasons for not using vendor supplied operating systems. Although many system design and performance goals were dictated by problems with vendor supplied systems, other goals surfaced as a result of a design for a custom system able to span multiple projects. System development and management problems and areas that required redesign or major code changes for system implementation are examined as well as the relative successes of the initial projects. A generic description of the actual project is provided and the ongoing support requirements and future plans are discussed.
The microcomputer array system is discussed with specific attention given to its electronic warware applications. Several aspects of the system architecture are described as well as some of its distinctive characteristics.
The program, LACREG, extracted all pixels that are contained in a specific IJ grid section. The pixels, along with a header record are stored in a disk file defined by the user. The program will extract up to 99 IJ grid sections.
The program, LACVIN, calculates vegetative indexes numbers on limited area coverage/high resolution picture transmission data for selected IJ grid sections. The IJ grid sections were previously extracted from the full resolution data tapes and stored on disk files.
The program, LACSEG, converts LAC/HRPT data tapes to the CSC defined Universal format. The Universal formatted data tape is then processed the normal way by the FAS IMDACS system.
A thermoelectrically temperature controlled quartz crystal microbalance (QCM) system was developed for the measurement of ion thrustor generated mercury contamination on spacecraft. Meaningful flux rate measurements dictated an accurately held sensing crystal temperature despite spacecraft surface temperature variations from -35 C to +60 C over the flight temperature range. An electronic control unit was developed with magentic amplifier transformer secondary power supply, thermal control electronics, crystal temperature analog conditioning and a multiplexed 16 bit frequency encoder.
Progress is reported in the creation of a two dimensional Fourier transformer for optical images based on the zinc oxide on silicon technology. The sputtering of zinc oxide films using a micro etch system and the possibility of a spray-on technique based on zinc chloride dissolved in alcohol solution are discussed. Refinements to techniques for making platinum silicide Schottky barrier junctions essential for constructing the ultimate convolver structure are described.
A modified APQ-102 sidelooking array radar (SLAR) in a B-57 aircraft test bed is used, with other optical and infrared sensors, in remote sensing of Earth surface features for various users at NASA Johnson Space Center. The video from the radar is normally recorded on photographic film and subsequently processed photographically into high resolution radar images. Using a high speed sampling (digitizing) system, the two receiver channels of cross-and co-polarized video are recorded on wideband magnetic tape along with radar and platform parameters. These data are subsequently reformatted and processed into digital synthetic aperture radar images with the image data available on magnetic tape for subsequent analysis by investigators. The system design and results obtained are described.
The paper describes an advanced technology development which utilizes a high speed analog/binary CCD correlator to perform the matrix multiplications necessary to implement onboard feature classification. The matrix manipulation module uses the maximum likelihood classification algorithm assuming a Gaussian probability density function. The module will process 16 element multispectral vectors at rates in excess of 500 thousand multispectral vector elements per second. System design considerations for the optimum use of this module are discussed, test results from initial device fabrication runs are presented, and the performance in typical processing applications is described
A spaceborne synthetic aperture radar (SAR) having pipeline multiple-look data processing is described which makes use of excessive azimuth bandwidth in radar echo signals to produce multiple-looking images. Time multiplexed single-look image lines from an azimuth correlator go through an energy analyzer which analyzes the mean energy in each separate look to determine the radar antenna electric boresight for use in generating the correct reference functions for the production of high quality SAR images. The multiplexed single look image lines also go through a registration delay to produce multi-look images.
The flight results show that the relative tri-redundant Inertial Measurement Unit IMU performance throughout the entire entry flight was within the expected accuracy. Comparisons are presented which show differences in the accumulated sensed velocity changes as measured by the tri-redundant IMUs (in Mean Equator and Equinox of 1950.0), differences in the equivalent inertial Euler angles as measured with respect to the M50 system, and finally, preliminary instrument calibrations determined relative to the ensemble average measurement set. Also, differences in the derived body axes rates and accelerations are presented. Because of the excellent performance of the IMUs during the STS-1 entry, the selection as to which particular IMU would best serve as the dynamic data source for entry reconstruction is arbitrary.