17,653 research outputs found
Evaluation of ERIM optically processed SEASAT SAR data
The results of three studies on the radiometric and geometric properties of optically processed SEASAT SAR imagery are summarized. The accuracy with which the image scale can be predicted based upon a knowledge of the SAR platform and recording system parameters and the processor characteristics was evaluated. The considerations involved in making radiometric measurements from image films, the use of point targets for calibrating the effects of Doppler spectrum shifts on the radiometric calibration of the SAR image data over extended swath lengths was evaluate
Expression of Interest ICES/KIS-3 : Thema 4: Hoogwaardig Ruimtegebruik Speerpunt 6
Hoofddoel van dit speerpunt is om zowel de Nederlandse overheid als het bedrijfsleven uit te rusten met een operationele kennisinfrastructuur die toegesneden is op de relatie tussen (antropogene en natuurlijke) klimaatverandering en meervoudig ruimtegebrui
An observational test of common-envelope evolution
By analysing and modelling the change in the abundance ratio of
C/C and O/O on the surface of the lower mass star
of a binary during the common-envelope (CE) phase of evolution, we propose a
simple observational test of the CE scenario. The test is based on the infrared
measurement of either the C/C or O/O ratio of red
dwarfs in post-common envelope binaries (PCEB's). In certain cases
(main-sequence red dwarf secondaries in PCEB's without planetary nebulae), as
well as determining whether or not accretion has occurred during the CE phase,
we can determine the amount of mass accreted during the CE phase and hence the
initial mass of the red dwarf component prior to the CE phase. In the other
cases considered (low-mass red dwarfs in PCEB's and red dwarf's in PCEB's with
planetary nebulae) we can only say whether or not accretion has occurred during
the CE phase.Comment: uuencoded compressed postscript. The preprint are also available at
URL http://www.ast.cam.ac.uk/preprint/PrePrint.htm
Acoustic radar investigations of boundary layer phenomena
A comparison is made between acoustic radar echoes and conventional meteorological data obtained from the WKY tower, for the purpose of better understanding the relationships between acoustic radar echoes and boundary layer processes. Two thunderstorm outflow cases are presented and compared to both acoustic radar data and Charba's gust front model. The acoustic radar echoes reveal the boundary between warm and cold air and other areas of mixing and strong thermal gradient quite well. The thunderstorm outflow of 27 June 1972 is found to compare with in most respects to Charba's gust front model. The major difference is the complete separation of the head from the main body of cold air, probably caused by erosion of the area behind the head by mixing with the ambient air. Two cases of nocturnal inversions caused by advection of warmer air aloft are presented. It is found that areas of turbulent mixing or strong thermal gradient can be identified quite easily in the acoustic radar record
YF-12 Lockalloy ventral fin program, volume 1
Results are presented of the YF-12 Lockalloy Ventral Fin Program which was carried out by Lockheed Aircraft Corporation - Advanced Development Projects for the joint NASA/USAF YF-12 Project. The primary purpose of the program was to redesign and fabricate the ventral fin of the YF-12 research airplane (to reduce flutter) using Lockalloy, and alloy of beryllium and aluminum, as a major structural material. A secondary purpose, was to make a material characterization study (thermodynamic properties, corrosion; fatigue tests, mechanical properties) of Lockalloy to validate the design of the ventral fin and expand the existing data base on this material. All significant information pertinent to the design and fabrication of the ventral fin is covered. Emphasis throughout is given to Lockalloy fabrication and machining techniques and attendant personnel safety precautions. Costs are also examined. Photographs of tested alloy specimens are shown along with the test equipment used
COLOR HOLOGRAMS FOR WHITE LIGHT RECONSTRUCTION
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70027/2/APPLAB-8-11-286-1.pd
Multi-frequency fine resolution imaging radar instrumentation and data acquisition
Development of a dual polarized L-band radar imaging system to be used in conjunction with the present dual polarized X-band radar is described. The technique used called for heterodyning the transmitted frequency from X-band to L-band and again heterodyning the received L-band signals back to X-band for amplification, detection, and recording
The economic optimisation of the main parameters of the 3-GeV electron booster synchrotron for DIAMOND
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