Very OT: Groud radar

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Happy New Year guys and gals !!

So far it's pretty OT, but hopes to make it Hot Topic when I got more info.

Does anyony knows the principles of a ground radar ? The one that can 'see' below the ground surface.
I guess it's like a metal detector, but more power and higher freguency.

Could be a fun project for a M128.

Tobias

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Our best friend Google says,
http://www.subsurfaceimaging.net...
Choose freely between the 'rollator' (what's that in english) and the
lawnmover type.
Now, I think you have to start with some power RF components and solder
all the way to M128.
Most likely to be fun, but maybe not within a hobbyists budget.

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gals ? i don't think there is any gal ever visit avrfreaks ?
happy 2004

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OK, GALs may have been abcent, as well as PALs and VHDLs.
But I know there has been some females at Avrfreaks.
Not so many, but some.

Tobias

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I do not know the regulations in your country but in the UK you have to obtain a licence while experimenting with the low frequency equipment and thee are restrictions in the frequency.

A common usage of units using low frequency stuff is cavers who use it fro communications and location.

Try looking for links under cave or underground communications and location.
Mike

Keep it simple it will not bite as hard

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Here is a starting point
http://www.sat.dundee.ac.uk/~arb...

Mike

Keep it simple it will not bite as hard

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it just happens that someone is selling one on ebay right now. Better hurry before it's gone. It can save you a lot of trouble building one yourself.
http://cgi.ebay.com/ws/eBayISAPI...

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bengan - "Most likely to be fun, but maybe not within a hobbyists budget."

Just for the record, some of us reading these forums are trained professionals and/or working in the industry.

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Just for the record, Mr Noname, I'm one of those.

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a lot of us are trained professionals, but also hobbyists. Few companies that your typical "trained professional" work for will consider doing something because it is "fun".
Therefore, whether you are a trained pro or not, chances are you will not have much more than a hobbyist's budget to work with if you want to do this...
(unless you are earning WAY more than me!)

regards
Carel

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Noname was me...now im home i'll log in properly.
So thats good. My point was there was no need to even consider whether it was for hobby or not, its irrelavant. Carel: while it may be true that many profs also work on a hobbiest's buget while doing private projects, whats stopping them using this forum for their working lives aswell? I know I for one have consulted these chronicles for work related queries on many occations. (A very handy resource indeed!)

Cheers
Steve

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Carel, Steve, glad to have you with us, you are both right.

Now back to the main issue, is anybody dying of eager to design
a ground radar with a M128?
Seems to me to be an app with a lot of data collection and heavy signal
processing. M128 wouldn't be my first choice of CPU.
But again, I'm being wrong before, once or twice ;)

As Mike previously points out, using metal detectors is prohibited also
in Sweden and most likely ground radars as well.
Every where you dig, you'll find a dead wiking.

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Bengt

I was not refering to metal detectors but to the frequencies one is allowed to use.

I am now wondering what it is Tobias means when he uses the term Ground Radar, as my mind went off into the direction of communications and point locations underground.
Mike

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My apologies Mike, you are correct.

The RF parts puts even more prohibitation to this case in Sweden.
As a wise guy said: "If it's fun, it's probably forbidden".

Yes, Tobias has been away for a while, sitting back amusing himself with
all the fuzz he started.

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I'm back !!

Thanks for all posting.

Mike, I mean ground penetration radar. Seems to be a fun thing to use.
I recon the design of the HF parts is somewhat tricky, maybe I'll drop the idea.
But it would be nice, to see things below the surface.
I watch Time Team on Discovery Channel, they do some archeological stuff, and the show is good fun to watch.

As for the data processing I think it's not that complicated, but that's becaouse I don't know better. Or the subject.

And Bengt, yes, I have been away for a awhile, I've been working. My new job gives very little chances to use the Internet, I have to do the surfing's at home.
My last post was 22h ago.....

Tobias

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Tobias, welcome back to life.

22h is an eternity for us freaks, 2 more and we had called the police and reported
you as a missing person.

I'm really glad that you got a new job, jobs are not easy found these days in
old Sweden, even if it keeps you away from the real stuff.

So, back to reality. Isn't it interesting to see how this type of discussion attracts
more post than all the other plain questions about what AVR too chose or what is
really a RTOS?

The reason I think data processing is heavy is that I belive you have to
move your radar on the surface collecting echos and also keeping track of
your coordinates. Then you evaluate all the echos with some funny
algorithm and out comes your radar image. Sounds simple but probably isn't.

So, how do you plan to proceed?

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Well, how do I proceed...?
1: I won't buy the $5500 GPR found in Ebay. This close to Christmas has drained all my econimic capabilities.
2: I don't know. I have to study the subject some more to determine if it's a realistic project.
I keep reading the links people has provided, but no real description or some schematics to glance at makes me lost in the ozone.

I beleive the hard part is to get a working radar, the data processing is probably the easiest part. I think.

Tobias

ps
Next week I'll be working evenings, then I'll be able to reply in an instant....

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Uhmm, getting the radar signal up and running is by far the easiest part. The algorithms used for image reconstruction and enhancement are absolutely THE worst I have ever seen. This is the dark corner of electromagnetic wave theory.
When I was in university friends of mine were working on detection of plastic landmines with GPR, let's say I'm glad it wasn't me.

When you get it to work it's really sweet though, so don't let me discourage you :-)

Igor

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Igor,

The question is IF I'm going to pursue this. It would be fun, but I need more sources if information if I'm going to try this.
I have to be somewhat sure it can be done (of course it can be done. it HAS been done before me...), otherwise it feels like putting alot of useful time to sleep.

Tobias, not yet discouraged....yet.....

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I don't know anything about the radar stuff itself, so I can't really help you out there. The signal processing depends on what you wish to find underground. Obviously finding a big rock is a lot easier than finding a piece of plastic.

Try to visualise the radar wave hitting the air to ground interface (which is not very neat and straight) and then diverging in all possible directions. All objects underground will produce a reflection and then all these reflections are added to form your return signal. It will be impossible to determine the underground direction of a return signal, so you'll have to take measurements in a grid. You can then start your reconstruction algorithms.

If I were you I would try all this by using sound waves first. All the same problems apply except you don't need a radar :-)
Something like trying to locate a big rock in a fish tank using ultrasound.

It still won't be easy though, good luck,
Igor

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HELLO ALL. CAN SOME HELP ME AND TELL WHATS THE CHEAPS WAY TO FIND A PVC PIPE UNDER GROUND THATS ABOUT TWO FOOT LONG.AND.IS ON A BLOCK AREA. AND ABOUT 3 FOOT DEEP ITS GOT MONEY IN IT ALL PAPER MONEY THANKS OGLEBE

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dig.

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HELLO ALL. CAN SOME HELP ME AND TELL WHATS THE CHEAPS WAY TO FIND A PVC PIPE UNDER GROUND THATS ABOUT TWO FOOT LONG.AND.IS ON A BLOCK AREA. AND ABOUT 3 FOOT DEEP ITS GOT MONEY IN IT ALL PAPER MONEY THANKS OGLEBE
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....with your hands.

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