Accession Number : AD0281751

Title :   AN ACQUIRABLE CODE,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Weiss ,Edwin ; Gorenstein,Daniel

Report Date : 09 JUL 1962

Pagination or Media Count : 8

Abstract : The problem of range measurement for vehicles in space is usually treated within the following framework. At the ground one transmits continuously a single sequence of very long period. This is received at the vehicle and retransmitted. Thus, at the ground a corrupted and out-of-phase version of the original sequence is received. By operating on it (usually by correlation techniques) one hopes to determine the phase, and then by measuring the elapsed time to find the distance in question (without ambiquity in virtue of the long period of the sequence). Such a sequence is known as an acquirable code. An elegant (though elementary) mathematical procedure is described for selecting an acquirable code; it rests on well-known properties of maximal length shift register sequences and on the Chinese Remainder Theorem. (Author)

Descriptors :   *ALGEBRA, *CORRELATION TECHNIQUES, *PHASE MEASUREMENT, *RADAR SIGNALS, *RANGES (DISTANCE)

Distribution Statement : APPROVED FOR PUBLIC RELEASE