Yes this two plane system was developed in Sweden and used in Canada in the early 1960s. Concept was that greater TX/RX separation, the greater the effective depth of exploration. Operated well in relatively level terrain where aircraft geometry could be maintained in a safe manner. Unfortunately, with over enthusiasm a survey was initiated in the Andes (Peru or Bolivia). The lead aircraft cleared the mountain peak but the trailing aircraft did not with loss of life. The operating group was associated with a Lundberg company (Ken would have more information on this). The original query, suggested that this two plane system was followed by INPUT. There were a lot of successful frequency domain AEM systems before the introduction of INPUT. Interestingly, the debate between greater depth with larger TX/RX separation AEM versus better resolution with shorter TX/RX separation, raged through out the 50s,60s,70s, 80s, 90s, 01s, whether fixed wing or helicopter. Perhaps it is still ongoing. David Fountain
Sent from my iPad > On Jul 17, 2019, at 2:50 PM, [email protected] wrote: > > > > > Today's Topics: > > 1. Fw: [GRVMAG] Re: 1960s ABEM airborne em system (Greg Hodges) > 2. FW: [GRVMAG] Re: 1960s ABEM airborne em system (Ken Witherly) > 3. Re: FW: [GRVMAG] Re: 1960s ABEM airborne em system (Richard Lane) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 17 Jul 2019 17:56:32 +0000 (UTC) > From: Greg Hodges <[email protected]> > To: "[email protected]" <[email protected]>, "[email protected]" > <[email protected]> > Subject: [SEGMIN] Fw: [GRVMAG] Re: 1960s ABEM airborne em system > Message-ID: <[email protected]> > Content-Type: text/plain; charset="utf-8" > > Nick:You're more likely to find someone with knowledge and experience with an > AEM system on the SEGMIN (SEG Mining) e-mail list.? (I know of it, but not > much detail.) > I've included that list here. > Greg Hodges > > ----- Forwarded Message ----- From: Nicholas Gant <[email protected]>To: > [email protected] <[email protected]>Sent: Wednesday, July > 17, 2019, 01:46:49 p.m. EDTSubject: [GRVMAG] Re: 1960s ABEM airborne em system > > Hello all, > this may not be the right forum to raise this query, but have any of you > really old folks recall, have knowledge about or had first or second hand > experience of the ABEM airborne em system of the early 1960s ? It was soon > replaced by the Barringer Input system. > The method used two fixed wing aircraft, one having a rectangular vertical > antenna/coil (say 4' x 6') mounted on top of the fuselage (the transmitting > coil ?), the other aircraft probably towing ?a multi coil sensor in a bird. > Photos I have show no wing-tip/tail/wing-tip/nose loop, so I assume the the > receiver antenna may be bird-mounted. > Again, I assume one aircraft followed the other, horizontal separation about > 100 m. It was not a successful system due to operating expense if nothing > else, one interpreter called it "stupid"..... > Has anyone any knowledge of this obsolete method, or have references to it ? > Best wishes, > Nick,Danville, CA.? > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://lists.geosoft.com/mailman/private/segmin/attachments/20190717/bae85f22/attachment-0001.html> > > ------------------------------ > > Message: 2 > Date: Wed, 17 Jul 2019 12:00:51 -0600 > From: "Ken Witherly" <[email protected]> > To: <[email protected]> > Cc: <[email protected]> > Subject: [SEGMIN] FW: [GRVMAG] Re: 1960s ABEM airborne em system > Message-ID: <[email protected]> > Content-Type: text/plain; charset="us-ascii" > > Dear Colleagues > > > > A query about old AEM systems showed up on the grav/mag server. I sent him a > Lundberg marketing booklet which is pretty good (published in 1959). Maybe > others have something they could contribute? > > > > Re > > > > From: [email protected] <[email protected]> On > Behalf Of Nicholas Gant > Sent: Wednesday, July 17, 2019 11:37 AM > To: [email protected] > Subject: [GRVMAG] Re: 1960s ABEM airborne em system > > > > > > Hello all, > > > > this may not be the right forum to raise this query, but have any of you > really old folks recall, have knowledge about or had first or second hand > experience of the ABEM airborne em system of the early 1960s ? It was soon > replaced by the Barringer Input system. > > > > The method used two fixed wing aircraft, one having a rectangular vertical > antenna/coil (say 4' x 6') mounted on top of the fuselage (the transmitting > coil ?), the other aircraft probably towing a multi coil sensor in a bird. > Photos I have show no wing-tip/tail/wing-tip/nose loop, so I assume the the > receiver antenna may be bird-mounted. > > > > Again, I assume one aircraft followed the other, horizontal separation about > 100 m. It was not a successful system due to operating expense if nothing > else, one interpreter called it "stupid"..... > > > > Has anyone any knowledge of this obsolete method, or have references to it ? > > > > Best wishes, > > > > Nick, > > Danville, CA. > > > > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://lists.geosoft.com/mailman/private/segmin/attachments/20190717/82abb795/attachment-0001.html> > > ------------------------------ > > Message: 3 > Date: Thu, 18 Jul 2019 04:49:48 +1000 > From: Richard Lane <[email protected]> > To: [email protected] > Cc: [email protected] > Subject: Re: [SEGMIN] FW: [GRVMAG] Re: 1960s ABEM airborne em system > Message-ID: > <CAPPQrLq+WvJ3=eCT1vCmZ0diPwtv9N=yaafga0qukqtbr3_...@mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hello Nick. > > Pemberton (1962) has a decent amount of information about the ABEM system. > > Pemberton, R. H., 1962, Airborne Electromagnetics in Review: Geophysics, > 27, 691-713. (https://doi.org/10.1190/1.1439081) > > ... Richard Lane > > > On Thu, Jul 18, 2019 at 4:01 AM Ken Witherly via SEGMIN < > [email protected]> wrote: > >> Dear Colleagues >> >> >> >> A query about old AEM systems showed up on the grav/mag server. I sent him >> a Lundberg marketing booklet which is pretty good (published in 1959). >> Maybe others have something they could contribute? >> >> >> >> Re >> >> >> >> *From:* [email protected] <[email protected]> >> *On Behalf Of *Nicholas Gant >> *Sent:* Wednesday, July 17, 2019 11:37 AM >> *To:* [email protected] >> *Subject:* [GRVMAG] Re: 1960s ABEM airborne em system >> >> >> >> >> >> Hello all, >> >> >> >> this may not be the right forum to raise this query, but have any of you >> really old folks recall, have knowledge about or had first or second hand >> experience of the ABEM airborne em system of the early 1960s ? It was soon >> replaced by the Barringer Input system. >> >> >> >> The method used two fixed wing aircraft, one having a rectangular vertical >> antenna/coil (say 4' x 6') mounted on top of the fuselage (the transmitting >> coil ?), the other aircraft probably towing a multi coil sensor in a bird. >> Photos I have show no wing-tip/tail/wing-tip/nose loop, so I assume the the >> receiver antenna may be bird-mounted. >> >> >> >> Again, I assume one aircraft followed the other, horizontal separation >> about 100 m. It was not a successful system due to operating expense if >> nothing else, one interpreter called it "stupid"..... >> >> >> >> Has anyone any knowledge of this obsolete method, or have references to it >> ? >> >> >> >> Best wishes, >> >> >> >> Nick, >> >> Danville, CA. >> >> >> >> >> >> >> ----------------------- >> SEGMIN community mailing list service ([email protected]). >> Change your personal options here: >> https://lists.geosoft.com/mailman/options/segmin/rjllane%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. >> > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://lists.geosoft.com/mailman/private/segmin/attachments/20190718/407684b7/attachment.html> > > ------------------------------ > > 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 13, Issue 9 > ************************************* ----------------------- SEGMIN community mailing list service ([email protected]). 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