## Search found 68 matches

Wed Feb 04, 2015 4:08 pm
Forum: Oil and Gas Exploration
Topic: Stanford scientists use ocean waves to monitor offshore oil and gas fields
Replies: 6
Views: 1860

### Re: Stanford scientists use ocean waves to monitor offshore oil and gas fields

This is what I read before: http://www.cbd.int/doc/meetings/mar/mcb ... gun-en.pdf

Although the noise influence is considered to be long range (thousands of km), usually there are no immediate severe impacts a few kilometer away.
Mon Feb 02, 2015 10:05 pm
Forum: Oil and Gas Exploration
Topic: Stanford scientists use ocean waves to monitor offshore oil and gas fields
Replies: 6
Views: 1860

### Re: Stanford scientists use ocean waves to monitor offshore oil and gas fields

Is it true that the noises from air guns for seismic surveys can be heard 4,000 kilometers away? It sounds it's much more powerful than ocean waves.
Mon Jun 09, 2014 3:52 pm
Forum: Near Surface Geophysics
Topic: How to Calculate SSS Layback Offset ?
Replies: 1
Views: 1880

### Re: How to Calculate SSS Layback Offset ?

It's not a difficult question in theory. The angle Φ is determined by the horizontal tow force F1 and the sea current force F2. The formula should be F1 * sin( Φ) = F2 F1 is apparently related to the towing speed. The faster the boat runs, the stronger F1 gets, and the smaller the angle Φ gets. F2 i...
Sun Nov 24, 2013 2:20 pm
Forum: Near Surface Geophysics
Topic: Estimate the Physical and Acoustic Properties of the Sea Bed Using Chirp Sonar Data
Replies: 1
Views: 890

### Re: Estimate the Physical and Acoustic Properties of the Sea Bed Using Chirp Sonar Data

Found the article:http://www.oe.fau.edu/CHIRP/A_Method_for_Estimating.pdf
It looks very interesting. Anyone has more insights I would like to know, too.
Fri Nov 01, 2013 3:09 pm
Forum: Near Surface Geophysics
Topic: Advice for buying a sub-bottom profiler
Replies: 18
Views: 18041

### Re: Advice for buying a sub-bottom profiler

We have not used the instrument in a while but it was working well when we shelved it. We have shifted our focus to high resolution, multi-channel towed streamer operations preferring to apply our techniques to imaging deeper strata. Would you mind to tell me what multi-channel towed streamer you s...
Fri Nov 01, 2013 1:08 pm
Forum: Near Surface Geophysics
Topic: Advice for buying a sub-bottom profiler
Replies: 18
Views: 18041

### Re: Advice for buying a sub-bottom profiler

WMGC wrote:Vlad... We have a used StrataBox for sale. Let me know if you are interested and I can provide more details.
How do you like this instrument?
Thu Sep 19, 2013 12:57 pm
Forum: Near Surface Geophysics
Topic: Advice for buying a sub-bottom profiler
Replies: 18
Views: 18041

### Re: Advice for buying a sub-bottom profiler

I use Chesapeake Sonarwiz.
Wed Sep 18, 2013 5:15 pm
Forum: Near Surface Geophysics
Topic: Advice for buying a sub-bottom profiler
Replies: 18
Views: 18041

### Re: Advice for buying a sub-bottom profiler

Yes, for the Edgetech system, you can save the data in SEG-Y format. There shouldn't be much problem for data processing. However, I doubt whether you should choose Hypack for the data processing. Hypack is good for side scan sonar data processing, but the functions for sub bottom data processing st...
Mon Sep 16, 2013 7:27 am
Forum: Near Surface Geophysics
Topic: Advice for buying a sub-bottom profiler
Replies: 18
Views: 18041

### Re: Advice for buying a sub-bottom profiler

The EdgeTech 3100 does not come with a processing software, but I am sure you can also use DELPH to process the data. About the price, maybe DELPH on this board can answer the question. I guess it's not cheap, but the software does look very nice.
Thu Sep 12, 2013 8:06 am
Forum: Near Surface Geophysics
Topic: Advice for buying a sub-bottom profiler
Replies: 18
Views: 18041

### Re: Advice for buying a sub-bottom profiler

I recommend Edgetech 3100, it is portable by hand (but it might need two people) and suitable for shallow water. I have used it in water as shallow as 6 feet and the data is still good. You can deploy it behind your boat with a rope without any problems. You may want the smaller antenna (SB424) inst...
Mon Apr 15, 2013 7:39 pm
Forum: Near Surface Geophysics
Topic: Side scan sonar
Replies: 4
Views: 4816

### Re: Side scan sonar

Tue Apr 02, 2013 5:21 pm
Forum: Near Surface Geophysics
Topic: Lakes and rivers investigations.
Replies: 1
Views: 1504

### Re: Lakes and rivers investigations.

Sub-bottom Profiler: Edgetech 3100 Portable Sub-bottom Profiler GeoAcoustic Sub-Bottom Profiling System Sidescan Sonar: GeoAcoustics Dual Frequency Sidescan Sonar Imagenex YellowFin Duel Channel Sidescan Sonar Got it from: http://forum.detectation.com/viewtopic.php?f=2&t=1650 Or you find sub bottom ...
Mon Feb 18, 2013 4:02 pm
Forum: Near Surface Geophysics
Topic: Need help with choosing a SBP
Replies: 6
Views: 3446

### Re: Need help with choosing a SBP

Considering the SBP-hostile sub bottom materials in your survey area, you should try something with the best penetrating depth first such as a boomer or sparker system. Manufacture-claimed penetration depths are based on very ideal conditions and are often too optimistic in real situations.
Fri Feb 01, 2013 10:17 pm
Forum: Near Surface Geophysics
Topic: PROSPECTING SUB BOTTON PROFILE USING FISCFINDER
Replies: 4
Views: 7525

### Re: PROSPECTING SUB BOTTON PROFILE USING FISCFINDER

Hummingbird series seem to be very popular. However, I am not sure a fishfinder can help you to locate gravels. The transducer frequency is typically hundredes of KHz, not penetrating through the sub bottom well. You may need to use sub bottom profilers.
Fri Feb 01, 2013 3:49 pm
Forum: Near Surface Geophysics
Topic: PROSPECTING SUB BOTTON PROFILE USING FISCFINDER
Replies: 4
Views: 7525

### Re: PROSPECTING SUB BOTTON PROFILE USING FISCFINDER

How thick and how deep are the gravel layers? How deep is the water?
Sat Jan 12, 2013 4:35 pm
Forum: Near Surface Geophysics
Topic: Sub bottom profiler
Replies: 63
Views: 73421

### Re: Sub bottom profiler

StrataBox has its own data acquistion software. You can use Chesapeake Sonarwiz to process the data.
Sun Dec 09, 2012 1:26 pm
Forum: Near Surface Geophysics
Topic: List of sub bottom profiler manufacturers
Replies: 7
Views: 17841

### Re: List of sub bottom profiler manufacturers

Comparison of the sub bottom profiling eqiupments:
http://www.hydro-international.com/file ... ent_13.pdf
Fri Jun 29, 2012 2:08 pm
Forum: General Geophysics and Geoscience
Topic: Wiggle traces: pressure or velocity?
Replies: 10
Views: 8415

### Re: Wiggle traces: pressure or velocity?

toastar, you got a point. It is well known in seismic surveys that geophone amplitudes do not directly represent the actual magnitude of ground velocity.
Thu Jun 28, 2012 7:31 pm
Forum: General Geophysics and Geoscience
Topic: Wiggle traces: pressure or velocity?
Replies: 10
Views: 8415

### Re: Wiggle traces: pressure or velocity?

I think here the "vertical component of velocity" is recorded by geophones instead of hydrophones, so there are positive and negative velocities.
Sun Jun 24, 2012 10:25 am
Forum: General Geophysics and Geoscience
Topic: Wiggle traces: pressure or velocity?
Replies: 10
Views: 8415

### Re: Wiggle traces: pressure or velocity?

The geophone we are talking about here is actually 3-component geophone recording movements of 3 orthogonal directions (z -vertical component; x and y are two orthogonal horizontal components).
Sun Jun 17, 2012 1:43 pm
Forum: Near Surface Geophysics
Topic: Syqwest Bathy 2010 vs Edgetech 3100
Replies: 10
Views: 6461

### Re: Syqwest Bathy 2010 vs Edgetech 3100

Bathy 2010 must be much cheaper than Edgetech 3100?
Sat Jun 02, 2012 9:54 pm
Forum: Oil and Gas Exploration
Topic: what gain recovery before tau-p slant stack?
Replies: 3
Views: 3831

### Re: what gain recovery before tau-p slant stack?

You can say all of them are correct. A gain applied to the data needs not to be unique, not even need to be the best. Spherical divergence in theory is based on point source, and t to power gains proved to be more practical in many cases based on experiences.
Wed May 16, 2012 8:06 pm
Forum: Near Surface Geophysics
Topic: Syqwest Bathy 2010 vs Edgetech 3100
Replies: 10
Views: 6461

### Re: Syqwest Bathy 2010 vs Edgetech 3100

Thanks! I know Edgetech 3100 system can do surveys in the water as shallow as about 2m, so it's definitely the choice for shallow water surveying.
Mon May 14, 2012 10:00 pm
Forum: Near Surface Geophysics
Topic: Syqwest Bathy 2010 vs Edgetech 3100
Replies: 10
Views: 6461

### Syqwest Bathy 2010 vs Edgetech 3100

Does anyone have experiences in using both instruments? What one is better?
Thu May 10, 2012 9:32 am
Forum: General Geophysics and Geoscience
Topic: Wiggle traces: pressure or velocity?
Replies: 10
Views: 8415

### Re: Wiggle traces: pressure or velocity?

Are you using the ocean bottom seismic data? If so, you can use both. They are different components/channels of the data.