Accession Number:

AD0243867

Title:

The Detection of Radar Echoes from the Sun

Descriptive Note:

Scientific rept. no. 9

Corporate Author:

STANFORD UNIV CA STANFORD ELECTRONICS LABS

Personal Author(s):

Report Date:

1960-08-24

Pagination or Media Count:

62.0

Abstract:

As previously reported, the April 1959 experiments utilized a transmission code sequence of rectangular pulses of thirty-second duration with a period of one minute. Detailed analysis of echo indication curve shapes and echo-indication positions yielded conclusive evidence of the receipt of solar echoes. Numerical values of the probability that the received solar echo indications in these trials could be caused by chance were computed to be on the order of one chance in a million. For the September 1959 trials a random length sequence of transmitted pulses was used with a higher-gain antenna arrangement. Increased solar activity during the period, along with equipment difficulties, prevented realization of the anticipated increase in the output signal-to-noise ratios. A study of the correlation characteristics of adjacent frequency bands in the solar-echo background-noise spectrum revealed correlation coefficients of consistently high values. The results of this study were used in a data reduction technique which resulted in a net improvement of the output signal-to-noise ratios. The improvement made possible by this technique was sufficient to enable detection of radar echoes from the sun in the September 1959 trials with computed error probabilities which are numerically smaller than those obtained in the April 1959 trials. Information obtained from the results of the initial solar echo trials will permit the detailed planning of future experiments from which additional knowledge may be gained of the solar corona, the solar magnetic fields, and the characteristics of the solar radio noise spectrum.

Subject Categories:

  • Celestial Mechanics
  • Active and Passive Radar Detection and Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE