Contributions in Honour of Irwin Scollar

Irwin Scollar shaped archaeological geophysics and aerial archaeology with many amazing innovations and the famous “black book” (1990). Many ISAP members benefitted from his immense wealth of knowledge. He celebrated his 90th birthday in November 2018 for which the contributions of ISAP members below are testimony of the profound influence he has had on the discipline.

Chris Gaffney (ISAP Chair) and Armin Schmidt (ISAP Honorary Secretary), October 2018

IrwinScollar died on 13 December 2021.

Links to Irwin Scollar’s software packages (especial AirPhotoSE):

[These links were last accessed on 5 Dec 2023; they are http links that may be blocked by your browser]

Short Curriculum Vitae

Irwin Scollar was born in 1928 in New York City. He completed his BSc degree in Electrical Engineering at the Lehigh University in 1948 and graduated from Columbia University in 1951, where he studied Classical Archaeology. In 1959 he received his PhD in Prehistoric Archaeology at Edinburgh University, UK. He moved to Germany in 1959 to work at the Rheinisches Landesmuseum in Bonn. He retired in 1991. Important milestones of his professional career in Archaeological Prospection were the introduction of systematic aerial photography from 1959, the systematic research and appliance of geophysical prospecting from 1960 and the computer evaluation of archaeological sites in Germany from 1961. One of his great achievements was the design and installation of the first large-scale system for computer image processing in archaeology in 1975. The volume «Archaeological Prospection» published by Scollar et al. (1990) is still a standard, summarizing his important contributions to this field of research. In addition to his work at the Rheinisches Landesmuseum, he received a lectureship at Bonn University between 1961 and 1966. From 1970 to 1974 he was consultant to the Gesellschaft für Mathematik und Datenverarbeitung for image processing methods. In 1980 he held a lectureship at the University of Cologne in computer methods for archaeology and in 1989 he received an honorary professorship at Cologne. He died on 13th December 2021.

More details and a list of references at ResearchGate and

International Conference and Workshop Pioneering Archaeological Prospection, Laa, Austria 2011
(Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology)

An Inspiration

Irwin Scollar died on 13th December 2021, aged 93. He was an Honorary Member of ISAP from the begining and will be missed by the community for his contributions and pioneering spirit.

Ever since I started in archaeological prospection Irwin’s publications and thoughts were an inspiration. Always sharp and ahead of the times there were insights amass. I tried to find even the most obscure of his references. Here is a short extract (my tarnslation) from Scollar, I. (1974). Einleitung. In E. M. Wilkinson, C. E. Mullins and A. Tabbagh (eds) Technische und Naturwissenschaftliche Beitraege zur Feldarchaeologie: vi-viii. Koeln: Rheinland-Verlag GmbH.

“All contributions of this volume of Archaeo-Physika require the reader to have specialised knowledge in physics and mathematics. Even if the older generation of archaeologists may feel excluded, the hope is that in future the propspects for this area of research will be better. Experts in archaeological organisations with the required scientific background will have no difficulties to fully appreciate the articles by Wilkinson, Mullins and Tabbagh.”

Similarly ahead of its time were the software developments for air-photo rectification (airphoto). And when I complained to Irwin about the end of support for the full package AirPhoto3 (in 2014) in favour of the free and user-friendly AirPhotoSE, he just commented: “You are probably the last one who still uses the gazillions of options in AirPhoto3”. And this was not meant as a compliment!


Armin Schmidt
(Dr Schmidt - GeodataWIZ)

From the early days …

I had my first contact with Irwin in 1983 when I was at high school and wanted to build a bleeper. At that time there were not many magnetometers around and hence I wanted to build an acoustic proton-magnetometer (for those of you who don’t know what a bleeper is). I wrote him a letter and got a response about hundred times longer than what I had written. He explained all the details and gave a lot of tips in this first letter and all the others following. I was really surprised that one of the most advanced scientists in archaeological prospection helped me so much (we only met in person much later). The first letter I wrote was in German but he answered in English and this has not changed until today.

Later on I visited him at the Landesmuseum in Bonn and I remember very well the lunch we had together. I expected that we would go to a restaurant, but Irwin simply took some sheets of the coloured printer paper (see scan below) used it as a tablecloth in front of the screen and started eating… Life can be so easy.

Living with computers was very different in those days. The printing paper mentioned above, for example, had grey and blue stripes. Some of these sheets survived and so that I can show one of the email replies from Irwin. As you can see the Internet was very difficult to navigate as there were different independent networks. Sending a message from one network to another was a complicated affair. You had to know the path of your message in advance and then use the appropriate syntax using semicolons or commas instead of a point etc. Therefore there were complete Internet Mailing Guides you had to consult before sending a message.

Apart from this printout, also a magnetic tape survived, which I have kept . It is labelled: ANSI LABEL, magpic, FILE=MAG.FTN, Block Size 4096. It was the main software Irwin used to create for the greyscale images out of magnetic data that were published in several of his papers and books. Of course the program was written in the most advanced language at that time, in FORTRAN. All his code was running on a big VAX, an excellent computer that continued working for a very long time. Unfortunately during one night the museum raised the mains voltage by 5 V. This was a very bad morning for Irwin: When he started his old workhorse at the start of the day, instead of the normal start-up there was only a distinct smell and some smoke…

Nevertheless Irwin never gave up and switched to more modern computers. After geophysical data processing and seriation he started working on aerial photo rectification and lately satellite data. Most of us will know the program AirPhoto and he also realised the potential of structure-from-motion at the very beginning. Today this technique is used by many people to create 3D models of any type and size in archaeology.

Irwin Scollar is an archaeologist by profession and decided to use his sound technical background to help archaeologists with modern techniques, whatever that was in the period. I am very glad to know him and I am deeply grateful for all his personal help and support.

Juerg Leckebusch
(Wüest Engineering AG)

Polish things

Writing this ‘birthday memory’ for Irwin made me realise that I’ve known him for more than half my life – a life that is some 15 years shorter than his own.  However…  In 1974, the Council for British Archaeology held what it called a ‘symposium’ that was later published as Aerial reconnaissance for archaeology edited by David Wilson.  In this, Irwin had a contribution about transformation of oblique aerial photographs that included a computer method that accurately converted a point from an image into its x, y and z coordinate values.  Transformation of single points is fine if your case study is a group of Roman camps, as Irwin’s was, but a couple of years later I began a research project which would have as its root a map of archaeological features in 4000 sq km of Wessex.  My sites were wiggly things and I needed a means of transforming those with reasonable accuracy to 1:10560 maps.  I wrote to Irwin, or Dr Scollar as he then was to me as a mere student, to ask if he thought this would be possible and we began a discussion of appropriate mathematical methods.  At the same time, I was talking over the possibilities with people in the Computer Lab, Engineering and Scott Polar here at Cambridge.  As Irwin would say, ‘to make a long story longer’, I eventually succeeded in writing a computer program that enabled me to transform sites in my area.  I sent him a copy of the code and there followed an invitation to his laboratory in Bonn where I spent a month in December 1977 and ended up with a more-elegant version of my program thanks to Bernd Weidner, Irwin’s assistant at that time.  After a little more correspondence, with Irwin urging me to follow various mathematical ideas and me wanting to get on with my archaeological project, we lost contact for 20 years.

Early in 1998, Otto Braasch told me that Irwin was writing a program for transformation of oblique aerial images and I contacted him asking to be a beta tester, an offer he gladly accepted.  There followed many hundred emails that, we both agree, eventually made his AirPhoto 3 a good and effective program.  I used AirPhoto variants in my commercial work and for research, and it became the program that was taught in the many workshops in Europe that were organised on behalf of AARG.  AirPhoto was good in those contexts because output could be set to the local grid – a grid sometimes added by Irwin to the program a few days before the workshop.  One case of such was a Polish grid that comprised five unequal portions and I know was a challenge for Irwin to program.  Anyway, the Polish grid system was added in time for our workshop in Poznań and I suggested that we teachers should get Irwin a thank you present that I could deliver a week later when I was going to visit him.

At his request, we bought a Krakov sausage.  It was of generous size, perhaps 20cm long by 5cm in diameter, which travelled back to Cambridge in my hold luggage along with some of its relatives.  A week later, I set off to Stansted taking just a small backpack with the sausage packed near the top as I thought it may be something unexpected by the security people.  Sure enough, I watched my bag go through the x-ray scanner once, then twice, after which a bloke called me over.  Unzipping my bag, he said there seemed to be a bottle of water in it, then he pulled out the offending item.  “Oh, it’s just a sausage”, he said and put it back.  I’m good at saying the wrong thing at the wrong time but for once I kept quiet while thinking to myself ‘plastic explosive?’  The sausage was duly delivered with our thanks for the Polish grid system.  Maria let him have a slice but is very strict about their diet and I wondered if the rest was consigned to the bin.  But the thought was there as are my best wishes to Irwin on his 90th birthday.  When things have calmed down after those celebrations, I look forward to continuing our occasional Skype chats.

Rog Palmer

A delayed backfire of the Cold War

Writing this happy-birthday message made us think of some of our past contacts with Irwin and his software AirPhoto.

When Irwin arrived in Germany, the Cold War had already enveloped Central Europe in the Iron Curtain. Little could he expect that its remnants would be chasing him well into the 21st century. In 1960’s the Soviets’ growing paranoia to protect parameters of the Pulkovo-1942 grid system (a paranoia caused amongst many factors by the development of the Keyhole satellite surveillance programme and GPS) forced the Eastern Bloc to withdraw it from the civilian use. Instead countries of the Warsaw Pact were obliged to introduce separate coordinate systems and so the most peculiar CS-1965 was born in Poland. The entire country was divided into five irregular zones which used two different projections and false eastings and northings in each zone. Furthermore, the grids were not concordant and it was impossible to combine maps along zone boundaries. In practice it meant an introduction of five separate grid systems (see diagram – Poland’s division into five zones (“Strefa”) in CS-1965).

Although the state-of-the-art system CS-1992 was implemented after the fall of communism, CS-1965 provided a full coverage for the country and for more remote areas it is still the only set of maps at 1: 10 000. This turned out important when we started extensive aerial reconnaissance in Poland. To be able to rectify oblique aerial photographs there was no other option but to ask Irwin to add CS-1965 in AirPhoto. In Spring 2007 after little over a month of email exchanges about ellipsoids, projections and datum, frantic digs for parameters in various institutions and learning how to answer Irwin’s questions, he could announce a successful implementation of the system which despite its peculiarities proved fully functional.

Four years later Irwin’s attempts to improve some tools prompted us to inform him that we were just witnessing the very end of CS-1965. At that time topographic maps were converted from CS-1965 into CS-1992 and full sets of maps were made available via geoportal. To this information only one answer could come:

Subject: S65 Strefa Boundaries
Date: 2011-01-26 09:14
From: Irwin Scollar <>
I’m sure that everyone will be pleased to see the end of CS-1965! I certainly will be among them. It caused me more work than any other of the 50 grid systems supported in AirPhoto. 

With best wishes to Irwin on his 90th birthday from the Polish aerial team.

Lidka Żuk, Włodek Rączkowski, Wojtek Mania

A visit to Japan

The time when we were first in contact was in the early 1970s. One of the elder colleagues from the Nara National Research Institute of Cultural Properties sent several aerial photographs to him asking whether some image enhancement could be applied. Through Irwin’s processing the moat of a mounded tomb, which was under a paddy field, became clear.

In the middle of 1980s, Irwin and his wife were invited to Japan as a specialist in photogrammetry by the Japanese Society of Photogrammetry and Remote Sensing (JSPRS). During their stay in Japan they visited our Institute in Nara on their way to Osaka. I had the opportunity to accompany them and introduce them to archaeological sites and historic places in the area. Irwin made several useful suggestions on archaeological prospection during our travel, especially when seeing “black” paddy fields. The time when we saw those fields was shortly after the harvest, and the straw scattered on the surface had been burnt. He pointed out that the homogeneous top soil and the burnt straw may result in difficulties when processing magnetometer survey data from the areas.

The photograph shows us together at the ICAP conference 2001 in Vienna, where Irwin gave one of the keynotes.

Yasushi Nishimura
(National Research Institute for Cultural Properties, Nara Japan)

Pioneer of Archaeological Prospection Irwin Scollar turns 90

Archaeological prospection is celebrating one of its very first pioneers: Irwin Scollar turns 90 in November 2018. Since the early 1960s, the US-born engineer and archaeologist has considerably influenced archaeological geophysics and aerial archaeology and his vast knowledge and ground-braking innovations have been an inspiration to a worldwide community in this discipline.

In October 2011 it was the LBI ArchPro’s honour to jointly organize the “Pioneering Archaeological Prospection” conference with Irwin Scollar in Austria. Some of the very first pioneers in the field, such as Martin Aitken, Mike Tite, Albert Hesse, John C. Belshé, Yasushi Nishimura, Otto Braasch and Helmut Becker, presented a retrospect on the early beginnings of archaeological prospection.

To mark the birthday of this highly respected luminary we have compiled recordings from the conference session as well as from a personal interview with Irwin Scollar in 2013:

The following article was written by LBI ArchPro historian Roland Filzwieser and is based on a series of face-to-face interviews he did with Irwin Scollar in 2011:

Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology

Software for Seriation

I never met Irwin Scollar personally, but I corresponded with him several times years ago when I was using WinBASP, the Windows update to the earlier command line version of BASP (Bonn Archaeological Seriation Program).  He was extremely helpful and conveyed a delightful personality, even via email.

WinBASP, as the name implies, was great for seriation.  It had other nifty features and other statistical operations.  My favorite was a module that plotted histograms of whatever variable you chose for different sites on a map.  It was quite impressive – and fun – at the time.  It seems you can still download it, and maybe it would run in a pre-Windows 10 emulation:

I’m sure I have a copy of it on. 3.5 inch floppy somewhere…

Mark Schurr
(University of Notre Dame)