Amplitude Fluctuation in Radar Echo Pulses
Abstract
The quality of data from a tracking radar and the value of certain lobing techniques depend upon the fluctuation characteristics of echo pulses. One such characteristic, the amplitude-frequency spectrum of amplitude noise, affects the choice of optimum sequential lobing frequency and the use of simultaneous lobing. The frequency spectrum of amplitude fluctuations in radar echo pulses has been calculated from experimental measurements for a number of airplane targets at X-band. The spectrum amplitude decreases with frequency with consistently greater slope for smaller planes. Motion of the plane as a whole appears to be the chief cause of fluctuation. Propeller modulation, a very noticeable effect at longer wave-lengths, was not observed. Results indicate that a high lobing rate, simultaneous lobing, and instantaneous automatic gain control can reduce the noise in the output angle of a radar significantly, provided the external fluctuation in angle of arrival and internal receiver noise are relatively small.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 21, 1949
- Accession Number
- AD1210715
Entities
People
- A. E. Hasting
Organizations
- United States Naval Research Laboratory