Search found 20 matches

by resour
Fri Oct 20, 2017 9:19 pm
Forum: Oil and Gas Exploration
Topic: 2D seismic data
Replies: 8
Views: 350

Re: 2D seismic data

Hi Kerim,

our tutorials show importing SEG-2 or ASCII formatted data only. However we also support importing SEGY shots since a few years.

Best regards, Siegfried.
by resour
Fri Oct 20, 2017 12:53 pm
Forum: Oil and Gas Exploration
Topic: 2D seismic data
Replies: 8
Views: 350

Re: 2D seismic data

Hi Kerim, how many channels are you using per shot ? We support up to 1'000 channels/traces per shot with our Rayfract® Pro license. See http://rayfract.com . Also we support interpretation of refracted/diving waves with DeltatV CMP refraction method. For theory see e.g. http://rayfract.com/pub/delt...
by resour
Sat Jul 22, 2017 11:11 am
Forum: Near Surface Geophysics
Topic: Borehole refraction
Replies: 0
Views: 317

Borehole refraction

Our new tutorial

http://rayfract.com/tutorials/KING17.pdf

shows interpretation of P-wave first breaks recorded with receivers positioned in 3 boreholes. Shot points are located along topography and in boreholes.
by resour
Wed Mar 15, 2017 4:54 am
Forum: Near Surface Geophysics
Topic: Circular receiver spread for refraction tomography
Replies: 0
Views: 341

Circular receiver spread for refraction tomography

Our new tutorial http://rayfract.com/tutorials/tunnel16.pdf shows imaging of tunnel excavation deformation zone. We now support circular receiver spreads with constant-velocity starting model. We allow blanking inside the circular spread (shown in above tunnel16.pdf) or blanking outside circular spr...
by resour
Sun Feb 05, 2017 6:14 am
Forum: Near Surface Geophysics
Topic: VSP constrained refraction
Replies: 1
Views: 542

Re: VSP constrained refraction

Our new slide show shows how to improve your first break picks. See

http://rayfract.com/tutorials/Slope1.pdf
by resour
Wed Sep 28, 2016 1:01 am
Forum: Near Surface Geophysics
Topic: VSP constrained refraction
Replies: 1
Views: 542

VSP constrained refraction

See tutorial

http://rayfract.com/tutorials/11REFR.pdf

showing joint inversion of refraction shots and VSP shots.
by resour
Sun Jul 10, 2016 4:44 am
Forum: Near Surface Geophysics
Topic: Best software for seismic refraction tomography
Replies: 76
Views: 61288

Re: Best software for seismic refraction tomography

For multiscale tomography using Steepest Descent method for SAGEEP11 blind refraction data see http://rayfract.com/tutorials/sageep11_smooth50.pdf For multiscale tomography using Conjuate Gradient method for SAGEEP11 data see http://rayfract.com/tutorials/sageep11_16.pdf and final tomogram after 8 W...
by resour
Wed Apr 13, 2016 9:40 am
Forum: Near Surface Geophysics
Topic: 3D seismic tomography
Replies: 10
Views: 2177

Re: 3D seismic tomography

Our new tutorials http://rayfract.com/tutorials/sageep11_16.pdf and http://rayfract.com/tutorials/multistep.pdf show multiscale 2D tomography using synthetic traveltime data with added Gaussian noise, generated for known subsurface models. We support exporting x/y/z/velocity from Surfer .GRD tomogra...
by resour
Sun Jun 22, 2014 5:45 am
Forum: Near Surface Geophysics
Topic: Best software for seismic refraction tomography
Replies: 76
Views: 61288

Re: Best software for seismic refraction tomography

For optimized interpretation with our Conjugate Gradient Fresnel volume tomography see updated http://rayfract.com/tutorials/ZONDDATA.pdf . See below for the final tomogram. We used a square cell sized 0.57m by 0.57m, resulting in a grid size of 41 rows vs. 183 columns and 7,503 nodes. WET inversion...
by resour
Fri Dec 20, 2013 9:08 am
Forum: Near Surface Geophysics
Topic: what is the shallowest refractor detectable with seismic refraction tomography
Replies: 8
Views: 1525

Re: what is the shallowest refractor detectable with seismic refraction tomography

http://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/hrsrt.pdf is a bad example, because seismograph-recorded shots are not corrected for a trigger delay of -0.2 ms. See Fig. 3(a), 3(b) for uncorrected shots. This explains the too low P-wave velocity at rock surface, in Fig. 6(a). When specifying "T...
by resour
Fri Nov 29, 2013 1:34 pm
Forum: Near Surface Geophysics
Topic: what is the shallowest refractor detectable with seismic refraction tomography
Replies: 8
Views: 1525

Re: what is the shallowest refractor detectable with seismic refraction tomography

Fresnel Volume Tomography resolution limit is about one wavelength. See Watanabe 1999 at http://xa.yimg.com/kq/groups/23477166/99226300/name/SGA001402.pdf As stated by Watanabe, "The Fresnel volume method generates tomograms that reflect the resolution accurately". Refraction methods that try to ima...
by resour
Fri Nov 22, 2013 7:35 am
Forum: Near Surface Geophysics
Topic: what is the shallowest refractor detectable with seismic refraction tomography
Replies: 8
Views: 1525

Re: what is the shallowest refractor detectable with seismic refraction tomography

When the subsurface is hard rock e.g. mine wall, first break signal frequency can be as high as 4,000 Hz. See http://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/hrsrt.pdf‎ . This allows imaging of refractor at depth of 0.15m, with receiver spacing 0.15m and shot spacing 0.3m. In theory, Fresnel Vo...
by resour
Sat Oct 05, 2013 2:20 pm
Forum: Near Surface Geophysics
Topic: Best software for seismic refraction tomography
Replies: 76
Views: 61288

Re: Best software for seismic refraction tomography

For a comparison of our Smooth inversion/WET tomography with other algorithms, based on SAGEEP 2011 blind refraction data see Blind Test of Methods for Obtaining 2-D Near-Surface Seismic Velocity Models from First-Arrival Traveltimes (Colin Zelt et al., JEEG Sep 2013) http://dx.doi.org/10.2113/JEEG1...
by resour
Wed Sep 04, 2013 9:58 pm
Forum: Near Surface Geophysics
Topic: Best software for seismic refraction tomography
Replies: 76
Views: 61288

Re: Best software for seismic refraction tomography

For updated .pdf showing 1D-gradient starting model obtained with 1.5D DeltatV inversion and horizontal averaging and 2D Conjugate Gradient Fresnel volume tomography see

http://rayfract.com/tutorials/ZONDDATA.pdf
by resour
Tue Aug 20, 2013 12:47 am
Forum: Near Surface Geophysics
Topic: Best software for seismic refraction tomography
Replies: 76
Views: 61288

Re: Best software for seismic refraction tomography

And here my S-waves.txt interpretation, also with 1D-gradient starting model and 100 WET iterations, wavepath width 20% :
by resour
Mon Aug 19, 2013 7:29 am
Forum: Near Surface Geophysics
Topic: Best software for seismic refraction tomography
Replies: 76
Views: 61288

Re: Best software for seismic refraction tomography

My interpretation of P-waves.txt, with 1D-gradient starting model and 100 WET iterations :
by resour
Sat Aug 17, 2013 6:30 am
Forum: Near Surface Geophysics
Topic: Best software for seismic refraction tomography
Replies: 76
Views: 61288

Re: Best software for seismic refraction tomography

My interpretation with Rayfract(R) 3.25 and pseudo-2D DeltatV starting model :
by resour
Sat Aug 17, 2013 6:19 am
Forum: Near Surface Geophysics
Topic: Best software for seismic refraction tomography
Replies: 76
Views: 61288

Re: Best software for seismic refraction tomography

For optimized interpretation of SAGEEP 11 blind refraction session see

http://rayfract.com/tutorials/SAGEEP11_13.pdf

with final tomogram as attached :