PSEUDORANDOM FREQUENCY MODULATION IN RANGE-DOPPLER RADAR.
Abstract
This study describes a class of waveforms suitable for simultaneous measurement of range and doppler shift. These waveforms are characterized by a uniform distribution in frequency and by a random rate of frequency change. Uniform frequency distribution is attained by a uniform spacing of frequencies with each frequency present for an identical length of time. A random rate of frequency change is attained by sequencing the frequencies by a pseudorandom number generator. Ambiguity functions are computed for pseudorandom frequency-modulated waveforms designed for ionospheric backscatter studies. By suitable choice of parameters, the ambiguity function consists of a narrow central peak surrounded by a plateau which is randomly fluctuating between zero and approximately twice its average. The pseudorandom frequency-modulated waveforms are generated by a frequency synthesizer controlled by a linear shift register. Identical waveforms are assured by a suitable frequency programming which returns the synthesizer to the same state at the beginning of each transmission. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1968
- Accession Number
- AD0836764
Entities
People
- Arpad Barna
Organizations
- Stanford University