dopsteeringvec

Doppler steering vector

Syntax

DSTV = dopsteeringvec(dopplerfreq,numpulses)

DSTV = dopsteeringvec(dopplerfreq,numpulses,PRF)

Description

DSTV = dopsteeringvec(dopplerfreq,numpulses) returns the temporal (time-domain) Doppler steering vector for a target at a normalized Doppler frequency of dopplerfreq in hertz. The pulse repetition frequency is assumed to be 1 Hz.

DSTV = dopsteeringvec(dopplerfreq,numpulses,PRF) specifies the pulse repetition frequency, PRF.

Examples

Compute Steering Vector for Doppler Shift

Calculate the steering vector corresponding to a Doppler frequency of 200 Hz. Assume there are 10 pulses and the PRF is 1 kHz.

dstv = dopsteeringvec(200,10,1000)

dstv = 10×1 complex

   1.0000 + 0.0000i
   0.3090 + 0.9511i
  -0.8090 + 0.5878i
  -0.8090 - 0.5878i
   0.3090 - 0.9511i
   1.0000 - 0.0000i
   0.3090 + 0.9511i
  -0.8090 + 0.5878i
  -0.8090 - 0.5878i
   0.3090 - 0.9511i

Input Arguments

dopplerfreq — Doppler frequencies

scalar | vector

Doppler frequencies in hertz, specified as a scalar or vector. The normalized Doppler frequency is the Doppler frequency divided by the pulse repetition frequency. Every element of dopplerfreq must be smaller than or equal to one-half the pulse repetition frequency PRF.

Data Types: single | double

numpulses — Number of pulses

positive integer scalar

Number of pulses, specified as a positive integer scalar. The time-domain Doppler steering vector consists of numpulses samples taken at intervals of 1/PRF (slow-time samples).

Data Types: single | double

PRF — Pulse repetition frequency

1 (default) | positive scalar

Pulse repetition frequency in hertz, specified as a positive scalar. The time-domain Doppler steering vector consists of numpulses samples taken at intervals of 1/PRF (slow-time samples). The normalized Doppler frequency is the Doppler frequency divided by the pulse repetition frequency.

Data Types: single | double

Output Arguments

DSTV — Temporal Doppler steering vector

column vector | matrix

Temporal Doppler steering vector, returned as a column vector or a matrix. DSTV has numpulses rows and a number of columns equal to the number of elements of dopplerfreq.

More About

Temporal Doppler Steering Vector

The temporal (time-domain) steering vector corresponding to a point scatterer is:

$$e^{j2\pi f_d{T}_{p}n}$$

where n = 0,1,2, ..., N – 1 are slow-time samples (one sample from each of N pulses), f_d is the Doppler frequency, and T_p is the pulse repetition interval. The product of the Doppler frequency and the pulse repetition interval is the normalized Doppler frequency.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

This function supports single and double precision for input data and arguments.

This function does not support variable-size inputs.

References

[1] Melvin, W. L. “A STAP Overview,” IEEE^® Aerospace and Electronic Systems Magazine, Vol. 19, Number 1, 2004, pp. 19–35.

[2] Richards, M. A. Fundamentals of Radar Signal Processing. New York: McGraw-Hill, 2005.

Version History

Introduced in R2011a