Engineering topics
Publications and source records attributed to Faust, N. L..
LANDSAT analysis system is assembled from commercially available components at relatively low cost. Small-scale system is put together for price affordable for state agencies and universities. It processes LANDSAT data for subscene areas on repetitive basis. Amount of time required for processing decreases linearly with number of classifications desired. Computer programs written in FORTRAN IV are available for analyzing data.
This study was performed to determine if Landsat data could be used to improve the accuracy of the estimation of cotton acreage. A linear classification algorithm and a maximum likelihood algorithm were used for computer classification of the area, and the classification was compared with ground truth. The classification accuracy for some fields was greater than 90 percent; however, the overall accuracy was 71 percent for cotton and 56 percent for soybeans. The results of this research indicate that computer analysis of Landsat data has potential for improving upon the methods presently being used to determine cotton acreage; however, additional experiments and refinements are needed before the method can be used operationally.
There are no author-identified signficant results in this report.
The paper details a minicomputer-based system which is well within the budget of many state, regional, and local agencies that previously could not afford digital processing capability. In order to achieve this goal a workable small-scale Landsat system is examined to provide low-cost automated processing. It is anticipated that the alternative systems will be based on a single minicomputer, but that the peripherals will vary depending on the capability emphasized in a particular system.
There are no author-identified significant results in this report.
The author has identified the following significant results. Survey results indicated that users of remote sensing data in the Southeastern U.S. were increasingly turning to digital processing techniques. All the states surveyed have had some involvement in projects using digitally processed data. Even those states which do not yet have in-house capabilities for digital processing were extremely interested in and were planning to develop such capabilities.
The transfer of remote sensing technology for the digital processing of LANDSAT data to state and local agencies in Georgia and other southeastern states is discussed. The project consists of a series of workshops, seminars, and demonstration efforts, and transfer of NASA-developed hardware concepts and computer software to state agencies. Throughout the multi-year effort, digital processing techniques have been emphasized classification algorithms. Software for LANDSAT data rectification and processing have been developed and/or transferred. A hardware system is available at EES (engineering experiment station) to allow user interactive processing of LANDSAT data. Seminars and workshops emphasize the digital approach to LANDSAT data utilization and the system improvements scheduled for LANDSATs C and D. Results of the project indicate a substantially increased awareness of the utility of digital LANDSAT processing techniques among the agencies contracted throughout the southeast. In Georgia, several agencies have jointly funded a program to map the entire state using digitally processed LANDSAT data.
The results of an effort to generate and apply automated classification of LANDSAT digital data to state of Georgia problems are presented. This phase centers on an analysis of the usefulness of LANDSAT digital data to provide land-use data for transportation planning. Hall County, Georgia was chosen as a test site because it is part of a seventeen county area for which the Georgia Department of Transportation is currently designing a Transportation Planning Land-Use Simulation Model. The land-cover information derived from this study was compared to several other existing sources of land-use data for Hall County and input into this simulation. The results indicate that there is difficulty comparing LANDSAT derived land-cover information with previous land-use information since the LANDSAT data are acquired on an acre by acre grid basis while all previous land-use surveys for Hall County used land-use data on a parcel basis.
It is known from several previous investigations that many categories of land-use can be mapped via computer processing of Earth Resources Technology Satellite data. The results are presented of one such experiment using the USGS/NASA land-use classification system. Douglas County, Georgia, was chosen as the test site for this project. It was chosen primarily because of its recent rapid growth and future growth potential. Results of the investigation indicate an overall land-use mapping accuracy of 67% with higher accuracies in rural areas and lower accuracies in urban areas. It is estimated, however, that 95% of the State of Georgia could be mapped by these techniques with an accuracy of 80% to 90%.
The feasibility of a postlanding orbiter rendezvous with one or both of the Martian moons during a 1977 or 1979 follow-on Viking mission is investigated. Rendezvous is considered for two Viking trajectory options: landing from orbit and direct entry. Mission feasibility is demonstrated for launch by the Earth-to-orbit shuttle and by the Titan/Centaur booster. Required changes to the 1975 Viking hardware are outlined. Integrating the rendezvous into the ongoing Viking mission is shown to be a cost-effective approach.
A description is given of the return of a manned Mars lander by a launch from the surface of Mars to some intermediate orbit, with subsequent maneuvers to rendezvous with a primary spacecraft (called the orbiter) in a Mars parking orbit. The type of Mars mission used to demonstrate the analytical technique includes a Venus swingby on the Mars-to-Earth portion of the trajectory in order to reduce the total mission velocity requirement. The total velocity requirement for the mission considered (if inplane launches are assumed) is approximately 17,500 ft/sec.
Inequality constraints in primer optimal N impulse solutions, introducing penalty function and its gradient with respect to control variables
Manned Mars lander launch-to-rendezvous analysis, using subsequent Venus swingby for mission velocity requirement reduction