Thank you for the hint On Sat, Nov 21, 2020 at 6:21 PM Annetts, David (Mineral Resources, Kensington WA) via SEGMIN <[email protected]> wrote:
> 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= > [email protected]> > 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... > URL: < > https://lists.geosoft.com/mailman/private/segmin/attachments/20201121/dfa43fad/attachment.htm > > > > ------------------------------ > > Subject: Digest Footer > > ----------------------- > SEGMIN community mailing list service ([email protected]). > Change your personal options here: %(user_optionsurl)s > 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. > > > ------------------------------ > > End of SEGMIN Digest, Vol 29, Issue 24 > ************************************** > ----------------------- > SEGMIN community mailing list service ([email protected]). > Change your personal options here: > https://lists.geosoft.com/mailman/options/segmin/se.geoscience.and.exploration%40gmail.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
----------------------- SEGMIN community mailing list service ([email protected]). Change your personal options here: https://lists.geosoft.com/mailman/options/segmin/archive%40mail-archive.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.
