Binary Moving Window Detector for staggered prf

[v***@gmail.com]

Hi all,

How do we apply Binary Moving Window detector/integrator (also known as
sliding-window detector or M-out-of-N detector) criterion for the case
of staggered prfs. That is to say suppose I have 5 prfs which I wish to
use in staggered manner. The suppose I want to apply 3-of-5 criteria at
the binary detection outputs of the CFAR.

Had it been the case of just one prf, I could have safely looked for 3
'ones' in a set of five and would have declared the target. However, in
the case of staggered prfs, my detections can be 'zero' if the target
is traveling with blind speed (and not because of the absence of a
target). How should I apply M-of-N detector in this case?

[rutiger]

I cant give you an answer, hopefully somebody will chime in here.
Could you design the PRFs so that each portion of the Doppler spectrum
was covered by the same number of PRF's (i.e no overlapping
blind-speeds but the union of them covered the entire spectrum)? Maybe
then you could use a 3-of-5 criterion using 6 PRFs, since any given
part of the spectrum is covered by only 5 of the 6 PRFs (reasonably at
least).

[v***@gmail.com]

Thanks Rutiger for replying.

Post by rutiger
Could you design the PRFs so that each portion of the Doppler spectrum
was covered by the same number of PRF's (i.e no overlapping
blind-speeds but the union of them covered the entire spectrum)?

same number of prfs? Do you mean 5, as I wrote in my message.

Post by rutiger
Maybe
then you could use a 3-of-5 criterion using 6 PRFs, since any given
part of the spectrum is covered by only 5 of the 6 PRFs (reasonably at
least).

But how I can use 6 prfs and apply 3-of-5 criteria. I will be
transmitting all 6 prfs in a single CPI, so I need to use M-of-6
criteria.

[rutiger]

Post by v***@gmail.com
But how I can use 6 prfs and apply 3-of-5 criteria. I will be
transmitting all 6 prfs in a single CPI, so I need to use M-of-6
criteria.

Would that be the case if any given portion of the spectrum was know to
only be covered by five of the six PRIs? I am reaching here, as CFAR
detection aint my thing.

[d***@yahoo.com]

Post by v***@gmail.com
However, in
the case of staggered prfs, my detections can be 'zero' if the target
is traveling with blind speed (and not because of the absence of a
target). How should I apply M-of-N detector in this case?

if the candidate-target would have been in the blind speed, then
you don't make his score higher or lower. You just wait till you have
done N looks where he SHOULD have been visible.

if it's a crewed system, you can give discretion to the crew leader to
exclude blinded wrfs from the set. He better know what he's doing.