ATIS Telecom Glossary
Saturday, October 25, 2014

A B C D E F G H I
J K L M N O P Q R
S T U V W X Y Z  
Go
 
Glossary Home
Foreword
Introduction
Normative References
Using the ATIS Telecom Glossary
Annex A: Informative References
 
 
 
<< Back
radar blind speed
The magnitude of the radial component of velocity of an object, i.e., a target, relative to a radar site, that cannot be measured by the radar unit. Note: Radar blind speeds occur because of the relationship between the transmitted pulse repetition rate (PRR) and the received pulse-repetition rate. The Doppler pulse repetition rate is the difference between the transmitted and received pulse repetition rates. For example, when the object is stationary with respect to the radar site, the reflected PRR is the same as the transmitted PRR and therefore a net zero signal is indicated for the radial component of velocity. If it happens that the Doppler PRR is the same as the transmitted PRR, i.e., the illuminating PRR, or it is a multiple of the transmitted PRR, a zero signal is also obtained and hence the radar is blind to these speeds, one for each multiple of the transmitted pulse repetition rate. It is not the absolute magnitude of the speed of the object that is measured, but only the radial component of the speed. The radial components of blind speeds, vm, are given by vm = mf/102, where v is the blind speed in knots, m is the multiple of the radar pulse repetition rate and the number of the blind speed, namely a positive integer, 1, 2, 3, 4, . . ., for the first, second, third, fourth, and so on, blind speed, is the wavelength of the illuminating radar in centimeters; f is the transmitter pulse repetition rate in pps (pulses per second); and the 102 is a units conversion factor. [From Weik '89]

 

 

 

 

 

 

 

 

 

 



 
These definitions were prepared by ATIS Committee PRQC
 
For more information on the work related to these definitions,
please visit the ATIS website and the ATIS Document Center