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To determine whether estimation process simulated by linear error analysis will converge, criterion has been developed based on extension of classical observability. Particular application of technique is with groups of batched navigation data where statistics of estimation errors are derived with classical minimum-variance methods.
The author has identified the following significant results. One result significant as a practical application and for cost benefit analysis is the relative ease with which ERTS-1 will monitor new and unclaimed stripping activities in Southeastern Ohio and in all of Appalachia. Band 5 resolution appears to be better than the often reported 80 meters. The strip mines stand out well enough to be easily identified without other graphic aids. Standing water within the strip mined area stands out in either bands 6 or 7. Areas of several acres are visible. Significant increases in surface extent of water of stripped areas should be detectable on a comparative basis. The degree of reclamation is observable in the imagery in rather gross percentage steps and for areas larger than the bare earth sizes in the table. The gradation in tones in the different bands indicates that probability density imagery using the four bands in CCT data (and statistical processing) is likely to separate degrees of vegetative reclamation.
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The author has identified the following significant results. Agricultural consultants have expressed substantial interest in work being conducted on center pivot irrigation and have inquired as to how ERTS-1 imagery can be used to aid those in the irrigation field. Results of the land use mapping experiment indicate that ERTS-1 imagery has major potential in regionalization. The ways in which land is utilized within these regions may then be studied more effectively than if no adequate regionalization is available.
Information needed to fabricate, transport, test, and launch space vehicles requires statistical meteorological data for various geographical areas. A brief review of world surface extremes is presented that illustrates the large extremum values that occur in some global areas and compares them with those currently used in space vehicle design.
Mariner 6 and 7 images are used to investigate the nature and importance of linear surface trends on Mars. Cross correlations of frequency-azimuth distributions of linear trends from different Mariner frames indicate that lineations not recognized as topographic features have a component of artifacts, probably introduced during digital reconstruction of the images. Consequently, topographic and nontopographic lineations should be treated separately prior to interpretation of the data. Similar statistical tests may aid in the analysis of surface trends from future satellites and space probes.
Five spatial features have been evaluated for their applicability in automatic land use classification of photographic imagery. Data arrays of approximately 10,000 square meters were classified on the basis of an 8 by 8 point data array. Statistical features, information features, sequency features and texture features were evaluated using a distance to prototype classifier and an adaptive classifier. The results indicate approximately 70% accuracy in the classification.
Results of observations of Cygnus X-2 are reported that were made with an X-ray telescope on board the OSO-7 satellite during the three intervals of January 9-16 and 21-26, 1972, and July 8-11, 1972. Random factor-of-two variations were found in the data. No statistically significant periodic variations were found in the range from 10 hours to 2 days.
The use of decision analysis to facilitate a group decision-making problem in the selection of trajectories for the two spacecraft of the Mariner Jupiter/Saturn 1977 Project. A set of 32 candidate trajectory pairs was developed. Cardinal utility function values were assigned to the trajectory pairs, and the data and statistics derived from collective choice rules were used in selecting the science-preferred trajectory pair.
The author has identified the following significant results. Surface water statistics using data obtained by supporting aircraft were generated. Signature extraction and refinement preliminary to wetland and associated upland vegetation recognition were accomplished, using a selected portion of the aircraft data. Final classification mapping and analysis of surface water trends will be accomplished.
A new magnetograph using a solid state monolithic linear silicon diode array has been constructed at Lockheed Solar Observatory. This magnetograph uses a digital image processor, and makes data available both in digital and analog form. The diode array detector is capable of a signal-to-noise ratio of 2000:1 or better when cooled to a temperature of -40 deg centigrade. Thus, intensity differences of the order of one part in a thousand may easily be detected without signal averaging. This instrument may be considered a prototype for an instrument using a two-dimensional array. The magnetograph is now fully operational, and is being used to produce data for statistical studies of solar magnetic field diffusion.
This paper describes the use of decision analysis to facilitate a group decision-making problem in the selection of trajectories for the two spacecraft of the Mariner Jupiter/Saturn 1977 Project. This NASA project includes the participation of some eighty scientists divided by specialization among eleven science teams. A set of thirty-two candidate trajectory pairs was developed by the Project in collaboration with the science teams. Each science team then ordinally ranked and assigned cardinal utility function values to the trajectory pairs. These data and statistics derived from collective choice rules were used by the scientists in selecting the preferred trajectory pair.
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No modulation of the 3-6 keV X-ray intensity of Sco X-1 at a level of excess of 1% was observed at the optical period of .787313d. Evidence is found for shot-noise character in a large fraction of the X-ray emission. Almost all of the Sco X-1 emission can be synthesized in terms of approximately 200 shots per day, each with a duration of approximately 1/3 day. A pinhole camera was used to obtain data and the data were statistically analyzed.
A double scintillator - double Cerenkov particle telescope, was used to study cosmic ray nuclei with Z greater than 14. This telescope had an exposure of 17,000 sq m-sr-sec and, consequently, the results obtained were of considerable statistical weight. Data are presented on the charge spectrum and on the energy spectrum over the sensitivity range of the Cerenkov detector. The data are compared with data available in the literature, and the implications are discussed.
The hot corrosion resistance of nickel-chromium-aluminum alloy was examined by cyclically oxidizing sodium sulfate coated specimens in still air at 900, 1000 and 1100 C. The compositions tested were within the ternary region: Ni; Ni-50 at.% Cr; and Ni-50 at.% Al. At each temperature the corrosion data were statistically fitted to a third order regression equation as a function of chromium and aluminum contents. Corrosion isopleths were prepared from these equations. Compositional regions with the best hot corrosion resistance were identified.
The hot corrosion resistance of nickel-chromium-aluminum alloys was examined by cyclically oxidizing sodium sulfate-coated specimens in still air at 900, 1000, and 1100 C. The compositions tested were within the ternary region: Ni, Ni-50 at.% Cr, and Ni-50 at.% Al. At each temperature the corrosion data were statistically fitted to a third order regression equation as a function of chromium and aluminum contents. From these equations corrosion isopleths were prepared. Compositional regions with the best hot corrosion resistance were identified.
Rolling element fatigue lives of eleven alloys were evaluated. The eleven alloys studied were three nitriding alloys (Super Nitralloy, Nitralloy 135, and Nitralloy N), four case carburizing alloys (AISI 9310, CBS 600, CBS 1000M and Vasco X-2), and four throughhardening alloys (Vasco Matrix II,AISI W-1, AISI S-2 and AISI O-2). Several different heat treatments and/or melting processes were studied on the three carburizing alloy steels. Metallurgical analyses were made before and after the RC rig tests. Test data were statistically analyzed using the Weibull distribution function. B-10 lives were compared versus VIM-VAR AISI M-50 and carburized VAR AISI 9310, as reference alloys.