# Homemade Ground Penetrating Radar for Privy hunting



## Rufus

[attachment=IMG_2247.JPG] Diggers,I have been working on a privy detector for 5 years now and have built pulse induction, ground conductivity, earth resistivity and thermal units. Unfortunately you can not beat GPR. Working on my third GPR system. The first one worked but detected other objects above ground as well because of the unshielded antenna. Second one worked well to about 10 feet but had noise problems and reflection issues. Both could find pits but the third one is using a state of art antenna/reflector and should see to 12 feet with very good resolution. The best part of the unit is I am trying to build it for less than 30 percent of a commercial system; making it affordable. Will keep you all posted and send scans of dug privies and un-dug privies. Karl


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## Rufus

Second Unit


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## Rufus

Third unit almost finished


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## Rufus

Reflector side


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## zecritr

nice


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## digger dun

Whoa. citizen scientist, citizen digger. Love it!


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## goodman1966

Waaaaaaaa!!!!! "CRYING LIKE A BABY" I want one !!!!!! That is so cool !!!!!   Mitch


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## goodman1966

Waaaaaaaa!!!!! "CRYING LIKE A BABY" I want one !!!!!! That is so cool !!!!!   Mitch


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## caldigs

I worked with a GPR unit for a few months and found it to be nearly worthless. It did find a few holes, but it certainly missed more than it found. The GPR only found pits that had a lot of metal,bricks, or really shallow trash. Essentially it found the new or shallow pits. Textbook pits with clean caps deeper than 3 feet were not detected by the machine. I have a feeling it will be quite some time before a machine can outperform the basic probe.


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## baltbottles

So is this just the antenna? And you would still need a laptop and software compatible to this antenna? I'm very interested in this as being an urban digger I have had the chance to dig in many places with several feet of overburden or modern fill that prevent probing. Chris


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## tigue710

do I see police radar detectors?  Very cool.  My digging partner and I worked with a magnetometer, but found it very unreliable.  The unit I had access to could have been damaged also so we couldn't figure out if it was us, a bad machine or just didnt work in the first place.  We practiced in graveyards with it first and the readings were 50/50 and did not read as they were supposed to.  I know some people have had luck with them and the machine we used found a very good privy in Sacramento before we had it.  Always wanted to try actual GPS.  You need a license to operate them in some states though.  I suspect the hard part with home made will be designing the software...


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## Rufus

The software is really user friendly (full color) and has standard GPR file format. Magnetometers are very poor for city work as any EMF prevents operation. This is a complete unit with cart and usb interface to PC. Will post more info soon. Karl


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## Rufus

GPR will never replace probing. It is great to cover large areas were probing is hard "Arizona soil". Then mark the spots and come back and probe to confirm. I actually use a T&T Tool slam probe and then dig a test hole. Software took hundreds of hours, actually lost track. FCC approval of system will cost between 15 and 20K at a certified lab. It will be legal in all 50 states. My goal was actually to make it for myself but it looks like I could sell it for the price of a high end Mine Lab and still make a little. Will post screen shots and finished unit soon. It will be housed in a Water tight Pelican Case. You can pull the unit or use a cart; cart will hold the PC. Also working on an Android app........for a tablet...... All the best and Happy New Year , Karl


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## sunrunner

well mate ,were just looking for bottles,right!your going to have to find,a hole full of indian qweens to cover you investment.


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## Rufus

Sunrunner,There are a lot of uses for GPR, utility surveys are the most common. But they are used for many things; archaeology, grave finding, landfill delineation, etc. These are the areas that have the market. Privy digging is just my hobby and I am benefiting from my work. I have dug hundreds of privies by using Sanborns and just by probing. But this unit opens up a whole new area. Scanned a ghost town recently with the second unit and found 8-10 privies in a nice row. It would have taken a week to probe and found them in 2-3 hours. Will attached some plots later. Also with GPR you can see right through asphalt and cement with no rebar. Karl


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## Rufus

Here is a plot from my second antenna; privy was under 3 inches of asphalt. Was given permission as asphalt was in very bad shape. Privy was 10 feet deep and plot shows information down to about 10 feet!


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## Rufus

I will give all bottle diggers a discount if I do sell any. My intent is just to use it myself as I have found more privies with it in a couple days of use than I could probe out in months. Will post the finished unit soon so everyone can get an idea of the size of the complete set up. Good digging to all and Happy New Year. Karl


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## LC

Is it just me or is anybody else experiencing pop up advertising that comes up when clicking on links from time to time . I think I may have a malware problem but want to ask to make sure . Replies appreciated ,Lou


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## Rufus

LC,
It sounds like your computer may have an issue as this site is clean of pop-ups.Karl


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## slakoper

How affordable would a unit like this be


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## Rufus

slakoper,My goal is to sell the unit "Pelican case enclosed" and rugged ground cart with Windows software for the price of a high end Minelab detector ; the GPX5000 sells for over $5000 new. My price goal is less than $5000 and hopefully less than $4000. GPR systems from GSSI or Mala start at $12,000. Hopefully with a good volume and reduced production effort less......Karl


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## cacarpetbagger

Tip of the hat to you.  Hope it works and find some good stuff.


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## Rufus

cacarpetbagger,Well it works well, see plot on first page of 10 foot privy under asphalt. It is just I want to make it as good or better than $12K commercial units. The antenna shown for my latest unit is far superior to commercial units. Have seen the interior of 4 different commercial units and they all use simple lump loaded bowtie antennas like my second unit. My current antenna design is based on a genetic algorithm from a University in Spain and instead of the normal 30-40 percent efficiency it is 97% efficient. Keep ya posted,Karl


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## westKYdigger

This is fascinating. Could you post some pics of the different types of readings you get in different situations? Like an urban setting, a hayfield & wooded lot.Thanks


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## Rufus

WestKYdigger,Will post some more plots once I finish the third unit. Will try to give a variety of plots; at least what Arizona can provide. Have a real nice Pelican case coming for this one, so should look good as well as work well.Thanks for your interest, Karl


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## Rufus

Admin,Thanks very much for the link; will check it out because I am just a one man show for now. I work full time also as an Engineer so time is scarce......Will be digging this weekend as I must pull some bottles out of the ground....Happy New Year, Karl


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## RICKJJ59W

caldigs said:
			
		

> I worked with a GPR unit for a few months and found it to be nearly worthless. It did find a few holes, but it certainly missed more than it found. The GPR only found pits that had a lot of metal,bricks, or really shallow trash. Essentially it found the new or shallow pits. Textbook pits with clean caps deeper than 3 feet were not detected by the machine. I have a feeling it will be quite some time before a machine can outperform the basic probe.


Agree 100%  if it ain't broke dont fix it. The simpler things in life are always the best in my eyes. Rember,it is the man behind the probe that finds the pits ;-) Cool project though I am sure someome will buy one.


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