time of arrival measurement for radar warning receivers(RWR)

[dipsbals]

hi I'm very new matlab and RWR . Tried and succeeded in generating composite ASK and then did FFT for freq spectrum and Hilbert transform for envelope detection. But now with this envelope detection i want to calculate TOA and then sort out the wave and meaasure PRI. Atleast i would be happy if anyone can help me to measure TOA just with this detected wave using matlab.
Thanks

 

[Mityan]

I think you may try to measure time interval between two fronts of your consequent pulses by taking a derivative. In ideal case (with low noise) this will be a one-sample (unit) positive pulse at front and negative at droop of your ASK. Interval between positive pulses is PRI. You may restart counter by that derivative.

 

[dipsbals]

I think you may try to measure time interval between two fronts of your consequent pulses by taking a derivative. In ideal case (with low noise) this will be a one-sample (unit) positive pulse at front and negative at droop of your ASK. Interval between positive pulses is PRI. You may restart counter by that derivative.

Hi very sorry i couldn't understand the explanation. What it means taking a derivative. My thought to solve this is to have a counter and whenever the pulses crosses a threshold level store the time. Similarly whenever the pulses fall below a threshold store the clock value as fall time. But how to use a counter for a stream of pulses in matlab is my problem.

 

[Mityan]

Derivative is the difference between adjacent samples. For square wave 00011111000000 the derivative will be 0001000-1000000.
Your logic is similar.
Concerning matlab you did not tell whether you have simulink model or m-file.

 

[dipsbals]

Derivative is the difference between adjacent samples. For square wave 00011111000000 the derivative will be 0001000-1000000.
Your logic is similar.
Concerning matlab you did not tell whether you have simulink model or m-file.

Hi I'm using only matlab to do this. I'm using tic and toc functions presently . If u have any suggestions please help me.

 

[Mityan]

Tic and toc are for true system time measurement. The time of code execution is not related to the sample time of your digitized input data. You should count the last one. Just samples which you operate I think.

 

[dipsbals]

Tic and toc are for true system time measurement. The time of code execution is not related to the sample time of your digitized input data. You should count the last one. Just samples which you operate I think.

hi finally achieved TOA measurement by setting a counter and calculated risetime and fall time of the pulse.