Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would
be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate
that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views.
It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if
you would like to post something on RF Cafe's
page, please do.
Below are all of the forum threads, including all
the responses to the original posts.
Post subject: Radar Pulse Stream Comparison
Posted: Wed Mar 16, 2011 5:40 am
Joined: Tue Mar 15, 2011 2:32 pm
I am currently working on a project with the aim to write a Matlab program to be able to analyse ESM received data.
I have both synthetic and real data to play with, which has been de-interleavered and has the following info:
1. Time of arrival
3. Pulse Width
5. Emitter ID
6. Stream ID
7. Confidence (1 or 0)
So I am basically number crunching in software, with no consideration to hardware.
The tricky part comes in the form of missing pulses or gaps in the stream.
I can assume the PRI of pulses by looking at one stream and calculating the median between TOA.
I have to find a way to compare fragments of streams together to determine whether they are in fact from the same emitter.
I know of ways to fill the gaps with null data then use various techniques such as Discrete Fourier to 'estimate', but my objective is to compare fragments.
I have already written code to filter the data down and provide a user interface for streams/certain emitters to be analysed.
Just wondered if any one had any ideas for comparison methods - I've been told that a similar technique is used in DNA matching?!?
Post subject: Re: Radar Pulse Stream Comparison
Posted: Thu Apr 28, 2011 4:38 pm
Joined: Mon Feb 25, 2008 4:53 pm
It's been a while since I worked on a radar project, but at the time (1990s) we were doing encoded pulse spreading specifically to prevent signature ID. It was sort of a mixture of DSSS and FHSS. It would be statistically impossible to relate successive pulses more than a few PRTs apart (in the case of long range interrogation) unless you had the emitter's vector identified. At that point, why do you need any more information?