Search found 341 matches

by nsm
Mon Jun 08, 2020 10:56 am
Forum: Near Surface Geophysics
Topic: Best GPR for underground utility locating
Replies: 7
Views: 736

Re: Best GPR for underground utility locating

RD1500 is cheap and fit certain market requirements, but it's definitely not the best GPR. There have been new models with this new fast stacking tech which is definitely better in penetration depth.
by nsm
Sat Jun 06, 2020 10:15 pm
Forum: General Geophysics and Geoscience
Topic: Guess geophysics terms (2)
Replies: 7
Views: 691

Re: Guess geophysics terms (2)

Plane wave... :thumbup:
by nsm
Tue Jun 02, 2020 5:14 pm
Forum: Near Surface Geophysics
Topic: Guess what's in the GPR profile
Replies: 9
Views: 601

Re: Guess what's in the GPR profile

The anomaly (4-8m marks)was an underground tunnel. If you look at it carefully, there were some small reflections (hyperbolas) just below its top horizontal layer. I believe they could be beams for a supporting structure inside the tunnel. The long hyperbola was actually a reflection from a pipe ove...
by nsm
Mon Jun 01, 2020 6:10 pm
Forum: General Geophysics and Geoscience
Topic: Filters used in signal analysis, FIR or IIR?
Replies: 3
Views: 359

Re: Filters used in signal analysis, FIR or IIR?

I have used both FIR and IIR in GPR data processing, I don't see much difference.
by nsm
Thu May 28, 2020 5:48 pm
Forum: Near Surface Geophysics
Topic: Geovizer.ru help
Replies: 10
Views: 480

Re: Geovizer.ru help

Geophex GEM2 is also an option.
http://www.geophex.com/Product_GEM2_handheld.htm
by nsm
Mon May 25, 2020 7:17 am
Forum: Near Surface Geophysics
Topic: Guess what's in the GPR profile
Replies: 9
Views: 601

Re: Guess what's in the GPR profile

ADobrovolskiy wrote:
Mon May 25, 2020 6:19 am
yes, now file imported without issues

it seems that antenna was elevated approx 2m above ground? Are you experimenting with drones?
No. The antenna was on the ground surface. Usually you need to adjust "time zero" first for GSSI GPR data. Nice data processing.
by nsm
Mon May 25, 2020 5:58 am
Forum: Near Surface Geophysics
Topic: Guess what's in the GPR profile
Replies: 9
Views: 601

Re: Guess what's in the GPR profile

OK, it's probably because it's an exported file and it had a slightly different format. I got the original file this time. Try downloading it again, it should work this time.
by nsm
Sun May 24, 2020 7:28 pm
Forum: Near Surface Geophysics
Topic: Guess what's in the GPR profile
Replies: 9
Views: 601

Re: Guess what's in the GPR profile

Here is the GPR data file zipped. GSSI 270MHz antenna.
GPR_Guess.zip
(420.25 KiB) Downloaded 26 times
by nsm
Sun May 24, 2020 9:31 am
Forum: Near Surface Geophysics
Topic: Guess what's in the GPR profile
Replies: 9
Views: 601

Guess what's in the GPR profile

I know it's hard to guess, but it's just for fun. Can you guess what these targets are in the GPR profile? There are two interesting targets here: one is around 30ns in depth and between 4 to 8 meter marks. The other one is the large hyperbola across the whole profile at 40ns and below. GPR guess.jpg
by nsm
Tue Aug 13, 2019 8:50 am
Forum: Near Surface Geophysics
Topic: Fresh water bathymetry using GPR
Replies: 4
Views: 3836

Re: Fresh water bathymetry using GPR

Hi, I would like to share data gathered from the drone using Cobra Plug-In GPR with SE-150 antenna https://drive.google.com/open?id=16lDd2j8RN4BWj3U-LqeLH3ghyMAVC7D8 Flight altitude 3m over water, speed 2 m/s Bottom is visible till 4+ meters 2019-07-15-15-03-37-gpr - processed.jpg Found a video, it...
by nsm
Mon Sep 07, 2015 9:09 am
Forum: General Geophysics and Geoscience
Topic: How to create a model in 3D from 3D data of ERT
Replies: 1
Views: 945

Re: How to create a model in 3D from 3D data of ERT

You can use Paraview. It's a free program and it might take you a while to learn how to do it, but it is actually not that difficult once you are familiar with its concepts.
by nsm
Sat Jul 25, 2015 8:03 pm
Forum: Near Surface Geophysics
Topic: Difficulty locating concrete sewer
Replies: 8
Views: 1774

Re: Difficulty locating concrete sewer

The properties of the concrete and the host soils might be very similar, so you can not see the concrete pipe itself. If this is the case, you are actually looking at voids (the air space inside the concrete sewer). If the sewer pipe is not big in diameter, you probably can't see it clearly in GPR p...
by nsm
Sat Jul 04, 2015 6:34 am
Forum: Near Surface Geophysics
Topic: GPR processing
Replies: 23
Views: 12433

Re: GPR processing

What do you use it for?
by nsm
Tue Apr 07, 2015 2:55 pm
Forum: Near Surface Geophysics
Topic: Need help to identify anomaly. Void or not!....
Replies: 7
Views: 1598

Re: Need help to identify anomaly. Void or not!....

Snow is fine for GPR signals, but you are going to get multiples from ground surfaces which you might think as subsurface layers. When possible, try to collect data with similar amount (thickness) of water and compare the results. I suspect the anomalies are simply caused by the water in the stream ...
by nsm
Mon Apr 06, 2015 6:08 pm
Forum: Near Surface Geophysics
Topic: Need help to identify anomaly. Void or not!....
Replies: 7
Views: 1598

Re: Need help to identify anomaly. Void or not!....

But it also looks like that the anomalies were caused by the water in the stream. I suggest you collect some data on locations nearby and compare the results. I think that the water depth could be too shallow for you to see deep depths because of multiples from the water bottom.
by nsm
Mon Apr 06, 2015 5:50 pm
Forum: Near Surface Geophysics
Topic: Need help to identify anomaly. Void or not!....
Replies: 7
Views: 1598

Re: Need help to identify anomaly. Void or not!....

It looks like it is water filled.
by nsm
Sun Apr 05, 2015 8:49 pm
Forum: Near Surface Geophysics
Topic: Need help to identify anomaly. Void or not!....
Replies: 7
Views: 1598

Re: Need help to identify anomaly. Void or not!....

it does look like a void. The reflection is strong and there is a ringing effect. What kind of gain functions have you used?
by nsm
Fri Apr 03, 2015 1:02 pm
Forum: General Geophysics and Geoscience
Topic: AML LOCATOR
Replies: 4
Views: 1138

Re: AML LOCATOR

I don't know what kind of reviews you want to see, but it seems to me that you still hold some hopes for this scam. Just forget about it, don't waste your money or even time on it.
by nsm
Fri Apr 03, 2015 8:07 am
Forum: General Geophysics and Geoscience
Topic: AML LOCATOR
Replies: 4
Views: 1138

Re: AML LOCATOR

by nsm
Wed Feb 18, 2015 7:51 pm
Forum: General Geophysics and Geoscience
Topic: Seismic Unix
Replies: 9
Views: 2104

Re: Seismic Unix

I don't know much about seismic unix, but if the size of your data is not large, you can use MATGPR. It's a free program, but you need Matlab installed on your computer. MATGPR has a very nice window interface so it's much easier to use for starters.
by nsm
Sat Jan 31, 2015 9:21 am
Forum: General Geophysics and Geoscience
Topic: imagen
Replies: 23
Views: 3479

Re: imagen

brooker wrote:Yes, but i think free program Is no good
Free program is good for something, depending on what you need...
by nsm
Fri Jan 30, 2015 4:21 pm
Forum: General Geophysics and Geoscience
Topic: imagen
Replies: 23
Views: 3479

Re: imagen

That's why I recommended free ones first :D