Hi Sergio, It's possible that LeroiAir can do what you need without an evaluation license. LeroiAis is referenced in Raiche, A. et al, 2007<https://www.tandfonline.com/doi/abs/10.1071/ASEG2007ab114> as well as by a few other authors.
While this can be used with Maxwell, it can also be used from the command line. David Annetts Ph.D. Senior Research Scientist Mineral Resources | CSIRO [email protected] | +61 8 6436 8517| 0411 756 129 26 Dick Perry Av. KENSINGTON, 6151, AUSTRALIA The information contained in this email may be confidential or privileged. Any unauthorised use or disclosure is prohibited. If you have received this email in error, please delete it immediately and notify the sender by return email. Thank you. To the extent permitted by law, CSIRO does not represent, warrant and/or guarantee that the integrity of this communication has been maintained or that the communication is free of errors, virus, interception or interference. CSIRO Australia’s National Science Agency | csiro.au<https://my.csiro.au/OrgInfo/Structure/Support/CorpAffairs/What-we-do/Brand-and-Marketing/www.csiro.au> ________________________________ From: SEGMIN <[email protected]> on behalf of [email protected] <[email protected]> Sent: Sunday, 22 November 2020 06:08 To: [email protected] <[email protected]> Subject: SEGMIN Digest, Vol 29, Issue 24 Today's Topics: 1. Re: Question about plate modeling with Maxwell (Greg Hodges) 2. Re: Question about plate modeling with Maxwell (S E Geoscience and Exploration) ---------------------------------------------------------------------- Message: 1 Date: Sat, 21 Nov 2020 21:40:48 +0000 (UTC) From: Greg Hodges <[email protected]> To: S E Geoscience and Exploration <[email protected]> Cc: "[email protected]" <[email protected]> Subject: Re: [SEGMIN] Question about plate modeling with Maxwell Message-ID: <[email protected]> Content-Type: text/plain; charset="utf-8" I presume that is homogeneous-halfspace apparent resistivity.? As long as they didn't heavily filter it (and it is likely they did) then you can forward model the apparent resistivity and height to get in-phase and quadrature, subtract the host I and Q (assuming it is significant) and then invert anomalies for a plate model. Rough, but better than nothing. Is there an apparent depth channel?? That would indicate a pseudo-layer (i.e. phase-amplitude) resistivity model, which would be better than an amplitude-altitude model.? If there is an apparent depth, add it to the measured altitude when you forward model the apparent resistivity to I and Q and it will do a better job of accommodating surface layers and/or altitude error. I'd be interested to know if EMIT includes apparent resistivity forward modeling in frequency domain.? (Don't tell them I said this, but them Australians don't do FDEM very well!? )? ? Greg Hodges On Saturday, November 21, 2020, 03:08:00 p.m. EST, S E Geoscience and Exploration <[email protected]> wrote: Thank you, Greg. I should have asked that question in more simple?words: I am working with a dataset (5 frequency Hummingbird system) which contains only the calculated apparent resistivity. Measured amplitudes (In-Phase and Quadrature) are missing. Would that be enough to do plate (forward) modeling? I guess it is.? Perhaps it is best to contact EMIT to get an evaluation license. Regards? On Sat, Nov 21, 2020 at 2:08 PM Greg Hodges <[email protected]> wrote: Hi, Sergio.I'm not sure I understand the question - or the problem - so maybe others don't either. If you're inverting (FDEM), the input is in-phase and quadrature (normally) and apparent conductance (conductivity-thickness product, or CTP) is a product along with the other plate parameters.?? If you're forward modeling, the conductivity is an input as part of the CTP, and the EM response is the product, or output.? From that EM we can estimate a CTP (and then assign a thickness to get conductivity), but that derived CTP depends on the plate model used.? Changes in the size of the plate (particularly the minimum dimension) change the phase angle (or decay constant in TDEM) and therefore the estimated apparent CTP and conductivity.? Of course, when forward modeling you can use the size of the model plate in your calculation of apparent conductance, but then you should get back the initial model conductance (in the absence of other interfering factors, like host response). So, what kind of model are you running, and what are you trying to get out of it? Greg Hodges On Friday, November 20, 2020, 05:17:12 p.m. EST, S E Geoscience and Exploration via SEGMIN <[email protected]> wrote: Re: Question about plate modeling with Maxwell? Dear all, It has been a while since I worked last with Maxwell. Do you?know whether we can model plates with just the calculated apparent conductivity and without the in-phase and quadrature amplitudes? Regards -- Sergio Espinosa, Ph.D., P.GeoDirector, GeophysicsS E Geoscience &?Exploration----------------------- SEGMIN community mailing list service ([email protected]). Change your personal options here: https://lists.geosoft.com/mailman/options/segmin/hodgesgreg%40ymail.com Colleagues can join here: https://lists.geosoft.com/mailman/listinfo/segmin Archives: https://lists.geosoft.com/mailman/private/segmin/ NOTE that <Reply> will reply to all members of the list. -- Sergio Espinosa, Ph.D., P.GeoDirector, GeophysicsS E Geoscience &?Exploration -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://lists.geosoft.com/mailman/private/segmin/attachments/20201121/f64a5b2c/attachment-0001.htm> ------------------------------ Message: 2 Date: Sat, 21 Nov 2020 17:08:44 -0500 From: S E Geoscience and Exploration <[email protected]> To: Greg Hodges <[email protected]> Cc: "[email protected]" <[email protected]> Subject: Re: [SEGMIN] Question about plate modeling with Maxwell Message-ID: <CAN2kzWJwsTb7-D=+yNvNZgWZ4TrAyPUeWc_Z=du_dkjkir+...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Greg, I only have Grids (X, Y) of AppCond for the five pairs of frequency/geometry. Regards On Sat, Nov 21, 2020 at 4:41 PM Greg Hodges <[email protected]> wrote: > I presume that is homogeneous-halfspace apparent resistivity. As long as > they didn't heavily filter it (and it is likely they did) then you can > forward model the apparent resistivity and height to get in-phase and > quadrature, subtract the host I and Q (assuming it is significant) and then > invert anomalies for a plate model. Rough, but better than nothing. > > Is there an apparent depth channel? That would indicate a pseudo-layer > (i.e. phase-amplitude) resistivity model, which would be better than an > amplitude-altitude model. If there is an apparent depth, add it to the > measured altitude when you forward model the apparent resistivity to I and > Q and it will do a better job of accommodating surface layers and/or > altitude error. > > I'd be interested to know if EMIT includes apparent resistivity forward > modeling in frequency domain. (Don't tell them I said this, but them > Australians don't do FDEM very well! [image: Emoji]) > > Greg Hodges > > > On Saturday, November 21, 2020, 03:08:00 p.m. EST, S E Geoscience and > Exploration <[email protected]> wrote: > > > Thank you, Greg. > > I should have asked that question in more simple words: I am working with > a dataset (5 frequency Hummingbird system) which contains only the > calculated apparent resistivity. Measured amplitudes (In-Phase and > Quadrature) are missing. Would that be enough to do plate (forward) > modeling? I guess it is. > > Perhaps it is best to contact EMIT to get an evaluation license. > > Regards > > On Sat, Nov 21, 2020 at 2:08 PM Greg Hodges <[email protected]> wrote: > > Hi, Sergio. > I'm not sure I understand the question - or the problem - so maybe others > don't either. > > If you're inverting (FDEM), the input is in-phase and quadrature > (normally) and apparent conductance (conductivity-thickness product, or > CTP) is a product along with the other plate parameters. > > If you're forward modeling, the conductivity is an input as part of the > CTP, and the EM response is the product, or output. From that EM we can > estimate a CTP (and then assign a thickness to get conductivity), but that > derived CTP depends on the plate model used. Changes in the size of the > plate (particularly the minimum dimension) change the phase angle (or decay > constant in TDEM) and therefore the estimated apparent CTP and > conductivity. > > Of course, when forward modeling you can use the size of the model plate > in your calculation of apparent conductance, but then you should get back > the initial model conductance (in the absence of other interfering factors, > like host response). > > So, what kind of model are you running, and what are you trying to get out > of it? > > Greg Hodges > > > On Friday, November 20, 2020, 05:17:12 p.m. EST, S E Geoscience and > Exploration via SEGMIN <[email protected]> wrote: > > > Re: Question about plate modeling with Maxwell > > Dear all, > > It has been a while since I worked last with Maxwell. > > Do you know whether we can model plates with just the calculated apparent > conductivity and without the in-phase and quadrature amplitudes? > > Regards > > -- > *Sergio Espinosa, Ph.D., P.Geo* > Director, Geophysics > *S E G*eoscience & *Ex*ploration > ----------------------- > SEGMIN community mailing list service ([email protected]). > Change your personal options here: > https://lists.geosoft.com/mailman/options/segmin/hodgesgreg%40ymail.com > Colleagues can join here: > https://lists.geosoft.com/mailman/listinfo/segmin > Archives: https://lists.geosoft.com/mailman/private/segmin/ > NOTE that <Reply> will reply to all members of the list. > > > > -- > *Sergio Espinosa, Ph.D., P.Geo* > Director, Geophysics > *S E G*eoscience & *Ex*ploration > -- *Sergio Espinosa, Ph.D., P.Geo* Director, Geophysics *S E G*eoscience & *Ex*ploration -------------- next part -------------- An HTML attachment was scrubbed... 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