Method of direct reception of swept-frequency topside sounder signals from ISIS-II through the ionosphere
Abstract
Swept-frequency topside sounder signals are received from the ionosphere on the ground by sweeping the receiving frequency, and synchronizing it with the frequency of pulses transmitted from the ISIS-II satellite (swept from 0.1 to 20 MHz in 20 sec). Various methods of frequency synchronization are examined and compared including phase locked loop methods and the method of estimating frequency change rate. Sequential estimation procedures using the Kalman filter are examined. The digital detection of frequency markers is considered taking account of false alarm probability and noise. The design of the receiving system is described with attention given to the receiver computer program.
- Publication:
-
Radio Research Laboratory, Journal
- Pub Date:
- July 1976
- Bibcode:
- 1976RaRLJ..23..111I
- Keywords:
-
- Frequency Synchronization;
- Ionospheric Sounding;
- Radio Receivers;
- Signal Reception;
- Sweep Frequency;
- Computer Programs;
- Hardware;
- Isis Satellites;
- Kalman Filters;
- Performance Tests;
- Sequential Analysis;
- Signal Detection;
- Communications and Radar