3,839 research outputs found
Digital correlation of DDRS data
The reduction of digital SAR (synthetic aperture radar) data to radar images for use in remote sensing applications was investigated. The critical software operations are discussed in detail, and suggestions and recommendations are made for improving the algorithms currently being used
APQ-102 imaging radar digital image quality study
A modified APQ-102 sidelooking radar collected synthetic aperture radar (SAR) data which was digitized and recorded on wideband magnetic tape. These tapes were then ground processed into computer compatible tapes (CCT's). The CCT's may then be processed into high resolution radar images by software on the CYBER computer
Development of a ground signal processor for digital synthetic array radar data
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
Application of Thermal Storage, Peak Shaving and Cogeneration for Hospitals
Energy costs of hospitals can be managed by
employing various strategies to control peak
electrical demand (KW) while at the same time
providing additional security of operation in
the event that an equipment failure or a
disruption of power from the electric utility
occurs. Some electric utilities offer their
customers demand (KW) reduction rate incentives.
Many hospitals have additional emergency back-up
needs for electrical energy. Demand is
relatively constant in many hospitals due to
high internal loads. These factors coupled with
the present competitive alternate fuel market
and present opportunities for hospitals to
significantly reduce operating costs and provide
additional stand-by or back-up electric sources.
This paper employs a hospital case study to
define and illustrate three energy planning strategies applicable to hospitals. These
strategies are peak shaving, thermal storage,
cogeneration and/or paralleling with the
electric utility
System engineering study of electrodynamic tether as a spaceborne generator and radiator of electromagnetic waves in the ULF/ELF frequency band
The transmission and generation by orbiting tethered satellite systems of information carrying electromagnetic waves in the ULF/ELF frequency band to the Earth at suitably high signal intensities was examined and the system maintaining these intensities in their orbits for long periods of time without excessive onboard power requirements was investigated. The injection quantity power into electromagnetic waves as a function of system parameters such as tether length and orbital height was estimated. The basic equations needed to evaluate alternataing current tethered systems for external energy requirements are presented. The energy equations to tethered systems with various lengths, tether resistances, and radiation resistances, operating at different current values are applied. Radiation resistance as a function of tether length and orbital height is discussed. It is found that ULF/ELF continuously radiating systems could be maintained in orbit with moderate power requirements. The effect of tether length on the power going into electromagnetic waves and whether a single or dual tether system is preferable for the self-driven mode is discussed. It is concluded that the single tether system is preferable over the dual system
Lifetime Bridge Maintenance Strategies Based on System Reliability
This study proposes a methodology for a system reliability-based condition evaluation of existing highway bridges. The approach is illustrated for an existing steel bridge located in Colorado. USA. An optimum lifetime repair strategy based on minimum expected cost is developed. The initial optimum repair strategy is updated using both biennial visual inspections and specific non-destructive evaluation testing
Image Analysis for Facility Siting: a Comparison of Lowand High-altitude Image Interpretability for Land Use/land Cover Mapping
For two test sites in Pennsylvania the interpretability of commercially acquired low-altitude and existing high-altitude aerial photography are documented in terms of time, costs, and accuracy for Anderson Level II land use/land cover mapping. Information extracted from the imagery is to be used in the evaluation process for siting energy facilities. Land use/land cover maps were drawn at 1:24,000 scale using commercially flown color infrared photography obtained from the United States Geological Surveys' EROS Data Center. Detailed accuracy assessment of the maps generated by manual image analysis was accomplished employing a stratified unaligned adequate class representation. Both 'area-weighted' and 'by-class' accuracies were documented and field-verified. A discrepancy map was also drawn to illustrate differences in classifications between the two map scales. Results show that the 1:24,000 scale map set was more accurate (99% to 94% area-weighted) than the 1:62,500 scale set, especially when sampled by class (96% to 66%). The 1:24,000 scale maps were also more time-consuming and costly to produce, due mainly to higher image acquisition costs
Mathematical modeling and SAR simulation multifunction SAR technology efforts
The orbital SAR (synthetic aperture radar) simulation data was used in several simulation efforts directed toward advanced SAR development. Efforts toward simulating an operational radar, simulation of antenna polarization effects, and simulation of SAR images at serveral different wavelengths are discussed. Avenues for improvements in the orbital SAR simulation and its application to the development of advanced digital radar data processing schemes are indicated
Application of Thermal Storage, Peak Shaving and Cogeneration for Hospitals
Energy costs of hospitals can be managed by
employing various strategies to control peak
electrical demand (KW) while at the same time
providing additional security of operation in
the event that an equipment failure or a
disruption of power from the electric utility
occurs. Some electric utilities offer their
customers demand (KW) reduction rate incentives.
Many hospitals have additional emergency back-up
needs for electrical energy. Demand is
relatively constant in many hospitals due to
high internal loads. These factors coupled with
the present competitive alternate fuel market
and present opportunities for hospitals to
significantly reduce operating costs and provide
additional stand-by or back-up electric sources.
This paper employs a hospital case study to
define and illustrate three energy planning strategies applicable to hospitals. These
strategies are peak shaving, thermal storage,
cogeneration and/or paralleling with the
electric utility
Guidelines for Energy Cost Savings Resulting from Tracking and Monitoring Electrical nad Natural Gas Usage, Cost, and Rates
This paper discusses how improved
energy information in schools and
hospitals from tracking and monitoring
electrical and natural gas usage, cost,
and optional rate structures, can reduce
energy costs. Recommendations, methods,
and guidelines for monitoring and tracking
of utilities are provided. These
recommendations, methods, and guidelines
are the result of on-site work for
schools and hospitals . Recently completed
energy usage survey and observations of
several hospitals in Texas are included.
Opportunities exist for schools,
hospitals, and other buildings t o achieve
significant dollar savings by good utility
management. Understanding utility rate
structures is essential for minimizing
energy costs. The authors' data is for
Texas schools and hospitals, but the
principles presented apply to other
geographic areas
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