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Need suggestions for literature: Radar/Sonar pulse design

Started by Rune Allnor March 11, 2005
Hi all.

I am involved in a project where we need to design
a signal for an active sonar type measurement device.
My background is mainly from seismics, where one usually
isn't very sophisticated what the source is concerned
("source signal design" is usually a matter of getting
an as loud "bang" as possible without using explosives).

In this project there is room for more sophisticated
approaches, and I am thinking along the lines of using
frequency-sweep signals and matched filters on the
receiving side.

I need some book or article (preferably available through
IEEExplore) that analyzes the matched filter in terms of
"processing gain", i.e. what is gained with respect to
ROC when using a particular signal and a matched filter,
compared to the "naive" AM modulated rectangular pulse
at a given SNR.

Any hints and suggestions are highly appreciated.

Rune

"Rune Allnor" <allnor@tele.ntnu.no> wrote in message 
news:1110539951.781399.136910@l41g2000cwc.googlegroups.com...
> Hi all. > > I am involved in a project where we need to design > a signal for an active sonar type measurement device. > My background is mainly from seismics, where one usually > isn't very sophisticated what the source is concerned > ("source signal design" is usually a matter of getting > an as loud "bang" as possible without using explosives). > > In this project there is room for more sophisticated > approaches, and I am thinking along the lines of using > frequency-sweep signals and matched filters on the > receiving side. > > I need some book or article (preferably available through > IEEExplore) that analyzes the matched filter in terms of > "processing gain", i.e. what is gained with respect to > ROC when using a particular signal and a matched filter, > compared to the "naive" AM modulated rectangular pulse > at a given SNR. > > Any hints and suggestions are highly appreciated. > > Rune
Hi Rune, You probably know that a whole lot of different "chirp" waveforms have been used for pulse compression in radar systems - many analyses published by IEEE - a search for chirp should uncover many references. Best of Luck - Mike
>
Am 11 Mar 2005 03:19:11 -0800 schrieb Rune Allnor:

> Hi all. > > I am involved in a project where we need to design > a signal for an active sonar type measurement device. > My background is mainly from seismics, where one usually > isn't very sophisticated what the source is concerned > ("source signal design" is usually a matter of getting > an as loud "bang" as possible without using explosives). > > In this project there is room for more sophisticated > approaches, and I am thinking along the lines of using > frequency-sweep signals and matched filters on the > receiving side. > > I need some book or article (preferably available through > IEEExplore) that analyzes the matched filter in terms of > "processing gain", i.e. what is gained with respect to > ROC when using a particular signal and a matched filter, > compared to the "naive" AM modulated rectangular pulse > at a given SNR. > > Any hints and suggestions are highly appreciated. > > Rune
A very good book about Radar: Introduction to Radar Systems, Merrill I. Skolnik, McGraw-Hill Education Siegbert
"Rune Allnor" <allnor@tele.ntnu.no> wrote in message 
news:1110539951.781399.136910@l41g2000cwc.googlegroups.com...
> Hi all. > > I am involved in a project where we need to design > a signal for an active sonar type measurement device. > My background is mainly from seismics, where one usually > isn't very sophisticated what the source is concerned > ("source signal design" is usually a matter of getting > an as loud "bang" as possible without using explosives). > > In this project there is room for more sophisticated > approaches, and I am thinking along the lines of using > frequency-sweep signals and matched filters on the > receiving side. > > I need some book or article (preferably available through > IEEExplore) that analyzes the matched filter in terms of > "processing gain", i.e. what is gained with respect to > ROC when using a particular signal and a matched filter, > compared to the "naive" AM modulated rectangular pulse > at a given SNR. > > Any hints and suggestions are highly appreciated. > > Rune
Rune, Windowing the edges of a CW only is pretty good. Chirping adds ambiguity - making range and Doppler harder to individually resolve. The idea of course is that time-bandwidth products higher than 1.0 as you get with a tone pulse are supposed to produce higher processing gain against noise. Much beyond that you need to start thinking about the signal bandwidth vs. the receiver bandwidth. In radar the receiver bandwidth can be fairly large compared to the signal bandwidth. In sonar this is often not the case if SNR is at all an issue. So, some radar techniques just don't work in sonar. (If anyone doubts this assertion, here's an example: radar can average results across multiple pulses whereas sonar generally must operate on a single pulse. Speed of light vs. speed of sound makes that difference.) If you are ambitious you might calculate the "noise" floor of a pseudo-random (frequency) sequence of "chips" (or constant frequency segments) run through a filter matched to the whole thing. With limited receiver bandwidth (thus signal bandwidth) you will find that the signal's intentional "noise" floor across the (limited) band is rather high - leaving little room for random noise. At least that's what I was told. In my mid-frequency, mid-range experience, getting much overall processing gain over a tone pulse is a bit elusive. In the end, it depends on your application...... How're you doing? Fred
Siegbert Steinlechner wrote:
> Am 11 Mar 2005 03:19:11 -0800 schrieb Rune Allnor: > > >>Hi all. >> >>I am involved in a project where we need to design >>a signal for an active sonar type measurement device. >>My background is mainly from seismics, where one usually >>isn't very sophisticated what the source is concerned >>("source signal design" is usually a matter of getting >>an as loud "bang" as possible without using explosives). >> >>In this project there is room for more sophisticated >>approaches, and I am thinking along the lines of using >>frequency-sweep signals and matched filters on the >>receiving side. >> >>I need some book or article (preferably available through >>IEEExplore) that analyzes the matched filter in terms of >>"processing gain", i.e. what is gained with respect to >>ROC when using a particular signal and a matched filter, >>compared to the "naive" AM modulated rectangular pulse >>at a given SNR. >> >>Any hints and suggestions are highly appreciated. >> >>Rune > > > A very good book about Radar: > Introduction to Radar Systems, Merrill I. Skolnik, > McGraw-Hill Education > > Siegbert
It is a very good book. Strangely it seems to be the *only* very good general book on radar. I don't think it has been updated for a long time. The last edition I saw was starting to look a little dated. It covers the ground in the original poster asked about, though (which, of course, it should since its a pretty basic question). Regards, Steve
Fred Marshall wrote:
> "Rune Allnor" <allnor@tele.ntnu.no> wrote in message > news:1110539951.781399.136910@l41g2000cwc.googlegroups.com... > > Hi all. > > > > I am involved in a project where we need to design > > a signal for an active sonar type measurement device. > > My background is mainly from seismics, where one usually > > isn't very sophisticated what the source is concerned > > ("source signal design" is usually a matter of getting > > an as loud "bang" as possible without using explosives). > > > > In this project there is room for more sophisticated > > approaches, and I am thinking along the lines of using > > frequency-sweep signals and matched filters on the > > receiving side. > > > > I need some book or article (preferably available through > > IEEExplore) that analyzes the matched filter in terms of > > "processing gain", i.e. what is gained with respect to > > ROC when using a particular signal and a matched filter, > > compared to the "naive" AM modulated rectangular pulse > > at a given SNR. > > > > Any hints and suggestions are highly appreciated. > > > > Rune > > Rune, > > Windowing the edges of a CW only is pretty good. > Chirping adds ambiguity - making range and Doppler harder to
individually
> resolve. > The idea of course is that time-bandwidth products higher than 1.0 as
you
> get with a tone pulse are supposed to produce higher processing gain
against
> noise. > Much beyond that you need to start thinking about the signal
bandwidth vs.
> the receiver bandwidth. > In radar the receiver bandwidth can be fairly large compared to the
signal
> bandwidth. > In sonar this is often not the case if SNR is at all an issue. So,
some
> radar techniques just don't work in sonar. > (If anyone doubts this assertion, here's an example: radar can
average
> results across multiple pulses whereas sonar generally must operate
on a
> single pulse. Speed of light vs. speed of sound makes that
difference.)
> If you are ambitious you might calculate the "noise" floor of a > pseudo-random (frequency) sequence of "chips" (or constant frequency > segments) run through a filter matched to the whole thing. With
limited
> receiver bandwidth (thus signal bandwidth) you will find that the
signal's
> intentional "noise" floor across the (limited) band is rather high -
leaving
> little room for random noise. At least that's what I was told. > > In my mid-frequency, mid-range experience, getting much overall
processing
> gain over a tone pulse is a bit elusive.
Thanks, all, for your answers. I'll see if I can get the Skolnik book.
> In the end, it depends on your application......
It's about measuring a "difficult" man-made structure. The thing does change, which is what we try to keep an eye (sorry, ear) on, but very, very slowly. We went to the lab and ascertained that the measurements we wanted to do were inded possible. They were, when we used single-period CW source signals, which came out as a Ricker pulse in the acoustics. The next stage now is to improve on the measurement device. One alternative is to use a large, high-power source with the same CW signal. I want to at least test some more elaborate lower-power signals before we make any decisions. I think it will work out OK, I'm just trying to prepare for one or two steps ahead.
> How're you doing?
Life is a little bit more exciting than hoped for, these days. Suffice it to say that I'm struggling to get my own company up and running. As you know, I haven't been the meekest or most servile disiple of contemporary Gurus in the underwater acoustics community, which has earned me something of a reputation in the professional community over here. Which, in turn, makes it all the more fun when I get involved in projects on my own terms (as opposed to having to stick to contemporary 'academic acoustic voodoo') and I actually manage to produce the results others have struggled literally for decades to get. Not that it is very complicated stuff we do, it's more that no one have tried acoustics for this particular type of measurement before, combined with certain recent technical modifications to an old design of the structure in question. And I haven't done very ground-breaking stuff to get the thing to work, either. I have only stuck to the very basic principles I used to teach in "Underwater Acoustics 101". No fancy model-based inverse modelling. No clairvoyant or omniscient signal processing schemes. No global searches. Just plain vanilla hands-on high-school level physics with just a *tiny* hint of "DSP 101" signal processing thrown in for good measure. Oh, there is one thing I did differently from other projects I have been involved in. It reduced my workload in the project by something like 99%: I got the customer, who has no background or interest in acoustics or DSP, to use their in-house general FEM modelling tools to simulate the wave propagation in this structure, before we went to the lab. It was a very useful excersise. Based on those movies, it was "obvious" why I suggested the procedure I did, and everybody who took part in the lab experiment were able to review, evaluate and interpret the data while in the lab. The lab results are encouraging, the customer is very happy and it brings me some income. Rune
Steve Underwood wrote:

    ...

> It is a very good book. Strangely it seems to be the *only* very good > general book on radar. I don't think it has been updated for a long > time. The last edition I saw was starting to look a little dated. It > covers the ground in the original poster asked about, though (which, of > course, it should since its a pretty basic question).
For a very good but very dated book, try "Principles of Radar" by the staff of the MIT Radiation Lab. (My son lost my copy.) Jerry -- Engineering is the art of making what you want from things you can get. &#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;
Rune Allnor wrote:
> Hi all. > > I am involved in a project where we need to design > a signal for an active sonar type measurement device. > My background is mainly from seismics, where one usually > isn't very sophisticated what the source is concerned > ("source signal design" is usually a matter of getting > an as loud "bang" as possible without using explosives). > > In this project there is room for more sophisticated > approaches, and I am thinking along the lines of using > frequency-sweep signals and matched filters on the > receiving side. > > I need some book or article (preferably available through > IEEExplore) that analyzes the matched filter in terms of > "processing gain", i.e. what is gained with respect to > ROC when using a particular signal and a matched filter, > compared to the "naive" AM modulated rectangular pulse > at a given SNR. > > Any hints and suggestions are highly appreciated. > > Rune >
I think that Cook and Bernfield is out of print. I think that Riachek's book was reprinted by Peninsula Publishers a while back. I've heard many people recomend Skolnick.
"Stan Pawlukiewicz" <spam@spam.mitre.org> wrote in message 
news:d149ah$p9n$1@newslocal.mitre.org...
> Rune Allnor wrote: >> Hi all. >> >> I am involved in a project where we need to design >> a signal for an active sonar type measurement device. >> My background is mainly from seismics, where one usually >> isn't very sophisticated what the source is concerned >> ("source signal design" is usually a matter of getting >> an as loud "bang" as possible without using explosives). >> >> In this project there is room for more sophisticated >> approaches, and I am thinking along the lines of using >> frequency-sweep signals and matched filters on the >> receiving side. >> >> I need some book or article (preferably available through >> IEEExplore) that analyzes the matched filter in terms of >> "processing gain", i.e. what is gained with respect to >> ROC when using a particular signal and a matched filter, >> compared to the "naive" AM modulated rectangular pulse >> at a given SNR. >> >> Any hints and suggestions are highly appreciated. >> >> Rune >> > > I think that Cook and Bernfield is out of print. I think that Riachek's > book was reprinted by Peninsula Publishers a while back. I've heard many > people recomend Skolnick.
It's Cook and BernFELD. It appears to be in print by Artech House. The original was from Academic Press. Amazon for $146.00 Still not what I'd recommend for directly applying to sonar except as background and interest. Fred
Fred Marshall wrote:
> "Stan Pawlukiewicz" <spam@spam.mitre.org> wrote in message > news:d149ah$p9n$1@newslocal.mitre.org... > >>Rune Allnor wrote: >> >>>Hi all. >>> >>>I am involved in a project where we need to design >>>a signal for an active sonar type measurement device. >>>My background is mainly from seismics, where one usually >>>isn't very sophisticated what the source is concerned >>>("source signal design" is usually a matter of getting >>>an as loud "bang" as possible without using explosives). >>> >>>In this project there is room for more sophisticated >>>approaches, and I am thinking along the lines of using >>>frequency-sweep signals and matched filters on the >>>receiving side. >>> >>>I need some book or article (preferably available through >>>IEEExplore) that analyzes the matched filter in terms of >>>"processing gain", i.e. what is gained with respect to >>>ROC when using a particular signal and a matched filter, >>>compared to the "naive" AM modulated rectangular pulse >>>at a given SNR. >>> >>>Any hints and suggestions are highly appreciated. >>> >>>Rune >>> >> >>I think that Cook and Bernfield is out of print. I think that Riachek's >>book was reprinted by Peninsula Publishers a while back. I've heard many >>people recomend Skolnick. > > > It's Cook and BernFELD. It appears to be in print by Artech House. The > original was from Academic Press. Amazon for $146.00 > Still not what I'd recommend for directly applying to sonar except as > background and interest. > > > Fred > >
Well Fred, what would you recommend?