Search found 88 matches

by 99thpercentile
Sat Aug 08, 2020 5:51 pm
Forum: Near Surface Geophysics
Topic: RIM method
Replies: 5
Views: 713

Re: RIM method

The RIM method is primarily used for low frequency (kHz to low MHz) crosshole imaging, primarily to detect voids in coal mines before additional mining. They also make an EM gradiometer for detecting shallow conductors. The EM gradiometer system has a passive tunable receiver and can use three diffe...
by 99thpercentile
Fri Aug 07, 2020 1:36 pm
Forum: Near Surface Geophysics
Topic: RIM method
Replies: 5
Views: 713

Re: RIM method

Stolar Global of Raton, NM, USA does this service and builds their own equipment.
by 99thpercentile
Tue Jun 23, 2020 10:56 pm
Forum: Near Surface Geophysics
Topic: Best GPR for underground utility locating
Replies: 8
Views: 1551

Re: Best GPR for underground utility locating

I have used most of the brands on the market and my current system is the Impulse Radar PinPointR. It uses real time sampling (RTS), operates at both 400 and 800 MHz, and is very compact in size. The price is very competitive at around $16K plus the tablet controller. I am using the Samsung Galaxy T...
by 99thpercentile
Sat Mar 07, 2020 5:40 pm
Forum: Near Surface Geophysics
Topic: Airborne ground penetrating radar
Replies: 16
Views: 13082

Re: Airborne ground penetrating radar

Why do you want to do airborne GPR on a river? I have done tons of geophysical surveys from walking to towing, to real helicopters and planes and also from unmanned aerial systems (UAS). In my opinion towed surveys are the sweet spot for value. Waterborne surveys are just another variation on towed ...
by 99thpercentile
Sat Mar 07, 2020 5:31 pm
Forum: Near Surface Geophysics
Topic: Locating a man made tunnel
Replies: 21
Views: 8861

Re: Locating a man made tunnel

Since it appears that you have more time than money, the target is relatively shallow, and relatively large versus the depth I would suggest electrical resistivity tomography. The DUOYI DY4300B 4-Terminal Earth Ground Resistance and Soil Resistivity Meter costs just over $300 USD for a kit with a re...
by 99thpercentile
Sat Feb 29, 2020 1:21 pm
Forum: Buy, Sell or Trade
Topic: Complete GSSI SIR-4000 GPR System for Sale
Replies: 1
Views: 3192

Re: Complete GSSI SIR-4000 GPR System for Sale

Is there any interest in a complete system like this? What would a good price be for the complete system? Would it be better to break it up into components to sell?

Thanks for any feedback.
by 99thpercentile
Sun Jan 19, 2020 5:17 pm
Forum: Buy, Sell or Trade
Topic: Complete GSSI SIR-4000 GPR System for Sale
Replies: 1
Views: 3192

Complete GSSI SIR-4000 GPR System for Sale

I have a GSSI SIR-4000 GPR controller along with several antennas and number of accessories that I want to sell. I would ideally be able to sell everything as a complete package, but if I can’t get a a reasonable price I might consider breaking some of it up into individual items. The SIR-4000 contr...
by 99thpercentile
Sat Oct 26, 2019 12:58 am
Forum: General Geophysics and Geoscience
Topic: Need a help
Replies: 2
Views: 2772

Re: Need a help

Since you seem to have acquired data from somewhere without a plan on what to do with it, I am going to assume that you don’t have a budget for processing and analysis software. If this assumption is incorrect, then please correct me. If this assumption is correct, then you might want to try Geopsy....
by 99thpercentile
Sat Sep 28, 2019 12:41 pm
Forum: Near Surface Geophysics
Topic: GIS
Replies: 17
Views: 8861

Re: GIS

You are stuck in the middle of a large industrial change. CAD and GIS software were originally designed for very different problem sets with very different needs. These types of software are controlled by two 800 pound gorillas, ESRI and Autodesk, who are on a collision course. Both are converging o...
by 99thpercentile
Sat Sep 28, 2019 12:13 pm
Forum: Near Surface Geophysics
Topic: Use ground penetrating radar with GPS
Replies: 30
Views: 33136

Re: Use ground penetrating radar with GPS

I’m glad you got your GPS working with your GPR. I’m sorry to hear that some manufacturers are still charging extra to use a capability that should be standard in 2019. I had some difficulties a few months ago when attempting to help some users get GPS working with a US Radar Quantum Imager. It was ...
by 99thpercentile
Tue Aug 20, 2019 8:51 am
Forum: Near Surface Geophysics
Topic: Use ground penetrating radar with GPS
Replies: 30
Views: 33136

Re: Use ground penetrating radar with GPS

What specific model of Mala GPR?
by 99thpercentile
Wed May 29, 2019 7:56 am
Forum: Near Surface Geophysics
Topic: gpr-slice demo version
Replies: 2
Views: 985

Re: gpr-slice demo version

What type of processing and analysis do you need to do? Are you just looking at profiles, or do you need time slices? What brand and model of GPR are you using? Each manufacturer has their own software which usually comes with the purchase of the equipment. If your university has GPR equipment, I ha...
by 99thpercentile
Thu May 09, 2019 10:44 pm
Forum: Near Surface Geophysics
Topic: need advice
Replies: 9
Views: 2222

Re: need advice

I don’t remember the details on that instrument but the founder of the company, Dr. Larry Stolarczyk, patented everything. So I would do a patent search under his name an you should find the details.
by 99thpercentile
Thu May 02, 2019 10:30 am
Forum: Near Surface Geophysics
Topic: need advice
Replies: 9
Views: 2222

Re: need advice

For commercial equipment I am aware of only one company working in this area. Stolar Global Imaging sells and also provides service for coal seam imaging. The system is a wound coil for low frequency radar imaging.

Stolar Global Imaging
http://stolarglobal.com/
Radar Imaging Method(RaiM)
by 99thpercentile
Sun Jul 29, 2018 9:00 pm
Forum: Near Surface Geophysics
Topic: PROBLEM WITH GSSI PROFILER EMP 400
Replies: 8
Views: 16433

Re: PROBLEM WITH GSSI PROFILER EMP 400

I realize that this post was from many years ago, but I was bored while sitting at my desk and waiting for some data processing to complete. I was skimming through old posts and saw this one. There are two problems that occur when you are making geophysical surveys on grids with alternating line dir...
by 99thpercentile
Sat Jun 16, 2018 10:03 pm
Forum: Buy, Sell or Trade
Topic: GSSI Antennas for Sale
Replies: 3
Views: 1196

Re: GSSI Antennas for Sale

USA
by 99thpercentile
Sun Jun 10, 2018 8:22 pm
Forum: Buy, Sell or Trade
Topic: GSSI Antennas for Sale
Replies: 3
Views: 1196

Re: GSSI Antennas for Sale

Both antennas are still available, $3000 each or best offer.
by 99thpercentile
Tue Mar 06, 2018 10:08 am
Forum: Buy, Sell or Trade
Topic: GSSI Antennas for Sale
Replies: 3
Views: 1196

GSSI Antennas for Sale

I have two GSSI antennas for sale, a 400 MHz and a 270 MHz. Both are in pristine condition but have been replaced with a 350 Mhz Hyperstacking (HS) antenna.
by 99thpercentile
Tue Jan 09, 2018 1:16 pm
Forum: Near Surface Geophysics
Topic: Bistatic antenna
Replies: 4
Views: 936

Re: Bistatic antenna

The first step in answering this question is to define bistatic and monostatic. Monostatic means that one antenna element is functioning as both the transmitter (Tx) and the receiver (Rx). All monostatic systems have the antenna in a single housing, while some bistatic systems have both Tx and Rx in...
by 99thpercentile
Tue Aug 29, 2017 11:45 pm
Forum: Near Surface Geophysics
Topic: Dielectric constant
Replies: 2
Views: 1076

Re: Dielectric constant

Most of my PhD research was on better ways to measure the electromagnetic properties of soils to improve detection of small compact targets. What frequency range are you interested in? What spatial scale are you interested in? What is your required accuracy? Do you have a fixed price that you are ta...
by 99thpercentile
Sun Jun 25, 2017 9:24 am
Forum: Near Surface Geophysics
Topic: US-Mexico Drug Tunnels Evolving Amid Increased Border Security
Replies: 4
Views: 1326

Re: US-Mexico Drug Tunnels Evolving Amid Increased Border Security

We have lots of methods for this specific problem. Some of them work well and some work really well. The issue is money, no one really wants to spend the money to solve the problem. I do this for a living and my group has been doing this since the early 1980s.
by 99thpercentile
Sun Feb 19, 2017 10:22 pm
Forum: Buy, Sell or Trade
Topic: Anyone willing trading a SIR3000 with a new 4000?
Replies: 3
Views: 1289

Re: Anyone willing trading a SIR3000 with a new 4000?

Did you solve this problem or are you still looking? If you are still looking, please send me an email at 99thpercentile@gmail.com.
by 99thpercentile
Mon Mar 14, 2016 7:29 am
Forum: Near Surface Geophysics
Topic: Horizontal Geophones
Replies: 6
Views: 1777

Re: Horizontal Geophones

I suggest making a Kirk shear wave source. If anyone wants it I have the PDF of the USGS Open File Report describing it. It can be modified so that you can do any polarization orientation of your source and then also your geophones, although the two most common orientations are parallel to survey li...
by 99thpercentile
Mon Dec 21, 2015 5:49 pm
Forum: General Geophysics and Geoscience
Topic: Which wiggle is the First Break?
Replies: 3
Views: 1262

Re: Which wiggle is the First Break?

This is a difficult question in GPR as well. There was a conference paper by Richard Yelf titled, "Where is True Time Zero?" published in 2004. Many of the GPR manufacturers use different definitions, either the the first negative break or the peak of the first positive break.
by 99thpercentile
Sun May 10, 2015 7:34 pm
Forum: General Geophysics and Geoscience
Topic: "Other" applications of seismic technology
Replies: 7
Views: 1779

Re: "Other" applications of seismic technology

Look into infrasound to see the seismic method most often used for comprehensive nuclear test ban treaty violations.