GPR image. Possible cache?

Klaus33 · Nov 16, 2007

Possible cache in an old farm wall. I would appreciate your
opinion about the GPR image. Thanks

Skifisher · Nov 16, 2007

So, is it in the wall? or underground?

Do you have a reference for size? Depth?

Did you check around it to rule out pipe or such?

Added:
Reading sonar or radar effectively, is sort of an art you develope from experience, similar to the sounds and using a metal detector, in a wall there are a lot of variables that would need to be taken into consideration as an overall picture to do an armchair call on that.

You must allready think this is an anomoly in the wall, therefore should have checked it out.

Klaus33 · Nov 16, 2007

The wall has about 10 feet wide and it does not consist that there are
metal infrastructures, is stone. The farm has more than 250 years.

Skifisher · Nov 16, 2007

Wouldn't be the first time something was plastered into a wall. I would say if you find an anomoly with that big of a differential return signature, I would check it out. Can you remove a rock that is covering that spot to take a look? how thick is the wall?

rebelLT · Nov 17, 2007

Is that what that is? A GSR image. Interesting. I know nothing about GSR so I guess I have no clue though I like the pretty colors

. Kinda like watching someone elses acid trip. IF I had any clue there was a treasure somewhere I would check it out. Though I would guess, based on you screen name and language, that you are German and maybe in Germany, perhaps. Remember that there could be a 155MM artillery shell or 500 pound bound under there also.

Klaus33 · Nov 17, 2007

Skifisher, the same filtered image (black and white)

MD Dog · Nov 17, 2007

I think especially in the black and white image above that even an amateur can tell there's an anomaly there. The only question is why would you need to ask about anyone else's take on this ? Why not just go ahead and dig or whatever to find out what it is ?That's what we all do with our MDs. We pick up anomalies in the ground structure, we then decide if what we have detected should be dug up, and in most cases the answer is yes, dig. That does kinda really hit home for all of us. Why do we question wether to dig or not ? There's an anomaly that we have detected in the ground, now maybe our tector is saying it's one thing but we all know our tectors are wrong at least as much as it is right. Therefore the answer should always be dig, cause that's the only way to know for sure what it is. Kinda like that cat in the box principle of uncertainty the teach in physics class.

sparkymaster · Nov 17, 2007

I don't know how to read your images but they're cool.

Run a detector over it and see what it does.

If it's close to a window or door it could be a counter weight.

HH

sparkymaster

99thpercentile · Nov 17, 2007

I have a series of questions about your GPR data. What brand of equipment did you use (Mala, GSSI, Sensors & Software)? Are the antennas monostatic or bistatic? What frequency was the antenna that you used? What value did you use for your dielectric permittivity to convert the time to depth? How did you determine your dielectric permittivity, did you do a common mid-point (CMP) survey to determine it? Do you have any pictures of the survey area? Did you do only one line? Did you migrate the data? How did you position the data, with a fiducial marker, a trigger wheel or GPS? What was your time window? How many bits did you use in the digitization?

Without the answers to most of these questions that even an experienced GPR user shouldn't wager a guess. The anomaly could be due to differential backfill during the construction of the wall.