Accession Number : ADP006190

Title :   Pattern Recognition Techniques Applied to the NASA-ACTS Order-Wire Problem,

Corporate Author : NATIONAL TELECOMMUNICATIONS AND INFORMATION ADMINISTRATION BOULDER CO INST FO R TELECOMMUNICATION SCIENCES

Personal Author(s) : Allen, Kenneth C.

Report Date : SEP 1989

Pagination or Media Count : 11

Abstract : The National Aeronautics and Space Administration (NASA) is planning to launch an Advanced Communication Technology Satellite (ACTS). This satellite will use several methods to adaptively mitigate the effects of fading due to rain in its 20- and 30-GHz links. A decision algorithm is needed to control the implementation of these mitigating techniques. The use of a learning pattern recognition algorithm as the solution to this problem is explored here. The algorithm is applied to data simulating fading on a slant path through the atmosphere at 20 and 28.8 GHz. The data were scaled from data measured on a 1-km path at 28.8 GHz in Hilo, Hawaii. The sole cause of fading in the data was attenuation due to rainfall on the path. The results indicate, at least for the test data, that the use of the most recently measured value of the received signal level (RSL), is adequate for predicting the future RSL and can be used to decide when the mitigating techniques should be used. More complicated algorithms based on linear combinations of previous RSL samples do not perform significantly better than the simple previous value approach.

Descriptors :   *FADING(ELECTROMAGNETIC WAVES), *PATTERN RECOGNITION, *RAINFALL, ALGORITHMS, ATMOSPHERIC ATTENUATION, SATELLITE COMMUNICATIONS.

Subject Categories : Radiofrequency Wave Propagation
      Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE