An Interesting Challenge

I caught this posting the other day on the C4ISR & Networks page:

Geospatial Sensors

This challenge got me thinking. Most of the requirements could easily be met using something like LiDAR – flood the target with enough laser sensors and you could track all the way down to the crickets chirping in the grass, in 4D. But the real challenge in this requirement is for a passive sensor that does not give away the user or sensor location. LiDAR and other systems that could tackle this challenge are all active systems – continuously bathing the target area with active signals in order to collect data. This makes them easy to detect with fairly rudimentary electromagnetic spectrum receivers (i.e., radios tuned to the right frequency).

So I started thinking. How could this problem be tackled with a passive collector system? For an old topographer like me the answer is simple – photogrammetric technology!  A pair of video cameras that collect high resolution imagery in a variety of spectrums (visible and passive IR) and have modern night vision capability could easily collect real time stereo still imagery (3D) and video (4D). They’d have to sit along a calibrated baseline, but that’s easy to establish using military grade GPS. All of this technology could be easily squeezed into fairly small, man-portable units. The data would have to be uploaded to computers for post-processing and visual display, and for real or near-real time use that implies some sort of a communications link. But still, the data collection part seems to me to be a simple application of available technology.

Hmm… maybe it’s time I hang out my shingle as a defense industry consultant!

– Brian



Map Makers At Work

I was going through some photos in my collection for some Facebook friends and ran across a collection of old shots I acquired while assigned to the 320th Engineer Company (Topographic) back in the late 1990s. I say ‘acquired’ because I just happened to find them lying around my office as part of some left over historical records from the old 649th Engineer Battalion (Topographic). All are 1970’s vintage photos that highlight the map making activities of the 649th. The 649th provided comprehensive topographic support – survey, map production & distribution, terrain analysis, and geographic intelligence analysis – to US Army Europe (USAREUR).

In the early 1980’s I was assigned to the 649th at Tompkins Barracks in Schwetizingen, Germany. I served as the commander of one of the terrain analysis detachments. I have a lot of good (and some not-so-good) memories of the 649th and the Soldiers that served in the unit. Fifteen years later I found myself back in Germany. By then the 649th had been deactivated and my unit, the 320th Engineer Company (Topographic), was the last surviving remnant of the 649th. The 320th had received a lot of left over equipment and paperwork from the 649th and one of my duties was to sort through it all to determine what was worth keeping and what could be trashed. During this process I found the photos you see in this post.

All of these photos were rejects, shots the photo editor didn’t think were worthy of using in a presentation. That accounts for a lot of the grease pencil ‘mark outs’ you see on many of the images. The interesting part is that the pictures that made it past the editor and into various publications or presentations are long gone – either packed up with the unit’s archives and locked away in an Army records warehouse or tossed into a trash can. Only the rejects survived to make it to my desk long after the battalion inactivated.

The 649th rarely made a new map from scratch. Most of the work involved updating existing maps or creating specialized overlays (like military operational graphics) to be overprinted onto existing maps. Still, the battalion had all the functional components necessary to create a new map:

  • Topographic and geodetic survey
  • Photomapping and cartography
  • Layout, photolithography and printing press operations

To accomplish these tasks each topographic company within the 649th was divided into three platoons – the Survey Platoon (topographic & geodetic survey), the Photomapping Platoon (photo control, compilation and drafting) and the Reproduction Platoon (layout, photolithography and press).

So let’s take a look at these processes as practiced by Soldiers of the 649th. This isn’t intended to be a comprehensive overview of map making; there are some large gaps in this tale simply because I don’t have any photos depicting specific steps. The real goal here is to highlight the Soldiers and their activities.



Each map starts with two things – stereo aerial photography and a topographic survey to ‘tie’ the photos to their location on the face of the earth. Army topographic units relied on US Air Force photomapping squadrons to provide the aerial photography. Once the topographic unit got the aerial photography in hand it was up to the surveyors to go out and collect precise location data for points visible in the photographs – things like road intersections, prominent terrain features or pre-positioned survey point targets.


APPS – the Analytical Photogrammetric Positioning System. The APPS permitted surveyors and terrain analysts to precisely determine points on the ground using georeferenced stereo images. The system consisted of a point positioning stereoscope hooked to an early HP desktop computer. Each set of stereo images came with a computer tape that held the ephemeris data for each image. The operator would pick a point on the image in stereo (road intersection, building roof, etc.), tap a foot switch and the computer would print out the point location in latitude and longitude. The APPS was often used by surveyors to collect photo control point coordinates without having to do a formal field survey. For its time this was a revolutionary system.



Surveyors ‘turning angles’ with a conventional theodolite (probably a Wild T2). The instrument would be set up over a known control point and used to measure the precise angle to other control points. The operator would call out the angle readings and the Soldier standing behind with the notebook would record the readings and do quick checks of the angle measurements to ensure the readings were accurate.



What are the surveyors in the previous photo aiming at? One of these, of course! This is a Wild survey target. It would get set up over a control point that is key to the survey. The theodolite operator adjusts the crosshairs in the theodolite telescope so they bisect the white ‘arms’ and ‘skirt’, of the target, then reads the angle of measurement.



 If a theodolite measures angles how do we measure distances? Well in the 1970’s we used microwave distance measuring equipment called the Tellurometer. The system consisted of a master and a remote unit and measured the time it takes a reflected microwave signal to return the master unit, which was then converted into distance. While I don’t have any hands-on experience using these units, I do remember sitting in on several meetings at the 649th where the surveyors discussed what a headache they were to operate and maintain. By 1980’s standards this was old technology and the units the Army had adopted were becoming maintenance nightmares. But in their time these distance measuring units were a revolutionary time saver. Note the headset the soldier is using. He’s actually talking to the operator at the remote unit via a built-in radio link. The two operators had to continuously coordinate settings and monitor performance during the distance measurement operation.



 Here is the back of the Tellurometer unit showing the instrument settings panel.



This picture shows the only Soldier in this series that I’ve met. CW2 Thomas (on the right) is demonstrating a new Hewlett-Packard calculator to a visiting British Army officer. CW2 Thomas was one of several survey warrant officers assigned to the 649th. We met at Fort Bragg, North Carolina years after this photo was taken. The Hewlett-Packard (HP) calculator is interesting because they were widely adopted by surveyors due to their rugged construction and advanced functions that were well suited to surveying applications. While I don’t think any HP pocket calculator was ever officially adopted by the Army they were in wide use at the Defense Mapping School where our surveyors were trained. Many of the HP calculators found their way into survey units through local purchase by individual units.




Photomapping is the process of compiling a topographic map based on information seen in the aerial photographs. Military topographic maps consisted of at least five distinct information layers, each with its own color – cultural features (black), water (blue), vegetation (green), contour lines (brown) and boundaries and built-up areas (red). It is the job of the cartographer to extract each of these information layers from the aerial photography to create a map manuscript. First the cartographers would rectify each aerial photo by removing any tip or tilt in the photo and tying it to the survey control points. Then they would use a device called a multiplex plotter to project the photos in 3D so the cartographer can trace out the key features while viewing the photos in stereo. Once the information is traced onto a manuscript sheet it is passed over to other cartographers who precisely trace out the collected information using the precise symbols we see on the finished map.


This photo shows a cartographer setting up a multiplex plotter in preparation for tracing out a new map information layer using photomapping techniques. The multiplex plotter used a stereo pair of aerial photos to project a 3-dimensional image of the terrain onto the white disc or platen of the mutiplex tracing ‘table’ (the device with the white disc seen sitting on the table). The tracing table has a small tracing dot engraved on it that sits directly above a pen holder. The stereo images have been transferred to two small glass diapositive images, and in this picture you see the cartographer holding one of the diapositives in his left hand as he mounts it into the projection stage. The tall ‘can’ in his right hand is the projector assembly that contains the projection lamp, lens assembly and filter. One diapositive is filtered red, the other blue, and the operator wears a pair of glasses with one red and one blue lens (just like the old-time 3D movie glasses), enabling him to see the projected image in stereo.


multiplex plotter

Here we see a cartographer tracing data from the projected image onto a manuscript sheet (usually a sheet of dimensionally stable material like Mylar). You can see entire image projected onto the the table surface just under his forearm, but only the small area projected onto the multiplex table platen is in focus. Engraved on the center of the platen is a small tracing ‘dot’, and mounted directly below it is a tracing pencil. The cartographer carefully adjusts the platen up or down so the tracing dot appears to rest directly on the ground on the stereo image and he then begins to trace out features. He traces one layer type onto each sheet; one sheet for cultural features, one sheet for hydrology (water), one sheet for vegetation etc.



Once a manuscript map layer is drawn it is turned over to other cartographers who carefully trace out the data using approved map symbols and line types. This is called the compilation process, where the cartographers compile the data into standard formats. Map compilation is precise and exacting work, and a cartographer can spend days, sometimes weeks, working on a single sheet.



Once each manuscript layer is complete it the information it holds is photographically ‘burned’ or transferred to specially coated plastic called either scribe coat or peel coat (seen above). The words ‘scribe’ and ‘peel’ describe the manner in which the orange coating (seen above) is removed to create clear windows through which a photographic negative can be exposed. Because of the unique nature of the orange coating it completely blocks all the light wavelengths that a film negative is sensitive to, so the orange areas come out black (or unexposed) when the negative is processed. Cartographers use specially designed scribing tools to carefully etch away the areas that represent point or linear features like individual buildings or roads. For larger areas like lakes or farm fields a sheet of peel coat is used, which allows large areas to be carefully cut with a sharp knife or razor blade and peeled away.



All military maps have grids, and the grid on each map is unique based on the area of the world it covers. Calculating and drawing these grids requires great precision and accuracy since the grids must be exact or the grid coordinates a Soldier derives from an improperly gridded map could be hundreds or thousands of meters off. Here a cartographer is setting up an automated plotting device used to precisely draw the grid for a particular map sheet. Automated tools like this greatly reduced the human error often encountered when drawing grids and speeded up map compilation.


Map Reproduction

Once the cartographers completed the map compilation phase the manuscript sheets were turned over to the Reproduction Platoon for all the steps necessary to print the final map. This normally involved preparing negatives from the scribe and peel coat layers prepared by the Photomapping Platoon, editing and correcting the negatives, making press plates and finally, printing the map.


To speed up the map compilation process cartographers made heavy use of pre-printed text. Things like standard place names (cities, towns, etc.), major feature names (rivers, mountains, etc.) and road identification symbols (highways, autobahns, etc.) would all be identified using standarized text that was prepared by the Reproduction Platoon. The cartographer would submit a list of feature names with text style and size requirements and the Reproduction Platoon personnel would provide the information on clear adhesive backed sheets that were created using a photo transfer process. Here we see a Soldier setting up some text as requested on the order sheet attached to the clipboard.



One of the last steps in map production is making the negatives from which the press plates are produced. Here we see a Soldier from the Reproduction Platoon doing a final check of a negative before approving it for plate production.



The final step before going to press is the plate making or ‘burning’. Press plates are just thin sheets of aluminum specifically sized to fit on a printing press. A map layer negative representing all features of the same color (black, blue, green, brown or red) is placed on top of a press plate that has been coated with a photo sensitive emulsion and the two are placed in a vacuum frame plate maker that uses a high intensity lamp to ‘burn’ or expose the positive image onto the plate. Once the plate is burned it is washed to remove the emulsion and the resulting image is what gets printed on the map. In this photo we see a Soldier from the Reproduction Platoon doing a final cleaning of a press plate before sending it on to the press section.



The 649th ran a number of presses of different size and capacity, everything from small trailer mounted presses capable of producing only 1:50,000 and 1:250,000 scale maps to large format presses permanently installed in the battalion’s base plant and capable of producing over-sized maps and other geographic products. In this picture we see a press operator from the Reproduction Platoon loading a press plate onto a van mounted Harris offset press.



Here’s a photo of one of the 649th’s presses installed in its baseplant at Tompkins Barracks in Schwetzingen.



Here’s a photo of the feeder end of another one of the 649th’s large format presses. In this photo it looks like already printed map sheets are being fed back through the press to add another information layer or military overprint.


Map Distro

The very last step in map production is actually map distribution. The 649th also had a Map Distribution Platoon that stocked and distributed the printed maps to units all across Europe. The platoon was responsible for getting the most current maps into the hands of the front line soldier as quickly as possible. The 649th maintained a map distribution warehouse at Tompkins Barracks and at several contingency sites around Europe. The platoon even had specially designed vans that were mobile distribution warehouses that could service forward deployed headquarters. Here we see Soldiers from the Map Distribution Platoon restocking maps at the distribution warehouse at Tompkins Barracks.


And there you have it, Army field map production circa 1970. As I mentioned in the start of this post I’ve taken a lot of liberties by overly simplifying the map making process with the intent of highlighting the Soldiers and activities of the 649th. If any readers recognize any of the Soldiers shown in these photos (or if you happen to be one of these Soldiers) I’d love to hear from you. You can either add a comment to this post or contact me at oldtopographer(at) If I’ve made any factual errors in the map making process, or if I’ve mis-identified any of the process shown in these photos please leave a comment here and I’ll make the necessary corrections. Thanks, and I hope you’ve enjoyed this trip down memory lane!

– Brian

Mapping the Assault!

OK now, everybody hum a few bars of the Barry Sadler song, Ballad of The Green Berets.

It’s the mid-1960s. The Vietnam war is still a ‘good’ war in the minds of most Americans. In 1961 President Kennedy had turned the spotlight on the US Army Special Forces, the Green Berets. When Kennedy found them they were an obscure group of soldiers operating out of Fort Bragg, North Carolina, led by officers who had worked closely with partisan groups during WWII and understood the value of conducting behind-the-lines operations to disrupt, demoralize and undermine an invading enemy’s operations. The Big Army brass didn’t much like them – they were independent, unorthodox, and perhaps worst of all they insisted on wearing those damned green berets. But they were having an impact, particularly in Southeast Asia where they were leading South Vietnamese and other native forces in surprisingly effective operations against the Viet Cong and other communist-inspired forces. The Big Army brass may not have liked these cocky Green Berets but there was no arguing they were having great success with their unorthodox methods and tactics.

Then in 1965 author Robin Moore published his best seller ‘The Green Berets‘, a semi-documentary novel of Special Forces operations in Vietnam. Moore had spent almost two years training and then deploying to Vietnam with a Special Forces unit so he was writing from the inside, with a special perspective on the unit, its men and its mission. (Significantly, Robin Moore is the first and, as far as I know, only civilian to attend and graduate from the US Army Airborne School at Fort Benning and earn his jump wings.) Moore’s book was an instant best seller. It pushed the Green Berets back into the spotlight and, this time, into popular culture. Suddenly America couldn’t get enough of the Green Berets. There were Green Beret magazine covers, comic books, toys, documentaries, songs and a John Wayne movie. And even trading cards. Yes, bubble gum trading cards!

Mapping the Assault In 1966 the Philadelphia Chewing Gum Corporation (P.C.G.C.) got the rights to use some US Army promotional photos on a series of trading cards about the Green Berets. There were 66 cards in the series (one card to a pack of gum to ensure brand loyalty and continued sales). The cards were typical Army stock photo stuff – Green Berets jumping out of airplanes, rappelling out of helicopters, training with machine guns, etc. All highly sanitized for mid-60’s pre-teen consumption. No blood, no gore, no torture (you know, the typical stuff a pre-teen sees today on prime-time television). I’m not sure how long the series ran, but I do remember seeing these cards for sale and buying a few myself while my family lived in New Jersey back in the 1960s.

Since this card is the only one of the set that deals with the use of maps I thought I’d toss it up here. It looks like the picture was taken during an exercise. The white tape pinned around the sleeves of some of the Special Forces soldiers indicates they are evaluators (‘white force’) for an exercise, and may be providing an overall exercise briefing to the two Green Beret soldiers standing on the right and staring intently at the map board. It must be raining outside, because these two visitors are wearing their wet weather jackets and they look damp.

The picture quality isn’t good enough to indicate what area the maps on the map board cover, but it’s a good bet that it’s somewhere around the Fort Bragg area. You can make out some geographic boundaries highlighted on the map board, and one has been named ‘Maple’ (or ‘Marie’) and the other ‘Woody’. Probably notional countries or regions created for use during the exercise. Based on the general patterns I see on the map board these are probably a series of Army Map Service 1:50,000 scale map sheets taped together to make one large, continuous coverage map.

There’s little else we can glean from the photo other than it’s cold (and wet) outside – many of the participants are wearing what look to be M-1951 field jackets. The overall setup has a familiar exercise control cell look about it, somewhat spartan with the field table and chair set before the map, a copy of the exercise order sitting on the table and some status boards and another map board hanging on the wall to the right. Been there, done that many, many times over.

I’m told by active duty soldiers that things haven’t really changed. Even in this era of unlimited bandwidth, live data feeds. advanced digital mapping and command and control software and high resolution large format displays there are still old-fashioned map boards that go up for every exercise ‘just in case’.

I guess the more things change the more they remain the same. Makes an old topographer smile.

– Brian

Send Out The Map Makers!

It’s 1908.  The Regimental Commander says “Hitch up the mules, we’re going on maneuvers!”

The Adjutant asks “Where, sir?”

The Commander points off to the horizon, “Why, out there of course!”

The Adjutant turns to the Regimental Engineer and asks, “Do we have any maps of ‘out there’?”

The Engineer says, “No, but we soon will!”

The Engineer turns to his assistant and says, “Send out the map makers!” And so it was!

GP Medium tent, duckboard flooring, folding cots, trenches to divert the rainwater and mud everywhere. Looks a lot like the 1st Cav Warfighter, Fort Hood, 1997.
If these guys are west of Yadkin Road without TA-50 there’ll be hell to pay! (Hat tip to old Fort Bragg hands.)
“Are you making fun of our big stick?”
I can’t say for sure where these photos were taken.  Two of the cards were postmarked at Fort Leavenworth so it’s possible the photos document classes taught as part of the Army Service Schools at Fort Leavenworth.  The Engineer portion of these courses included heavy emphasis on field survey and sketching.

The photographer, Waldon Fawcett, did a lot of photography for the US government right after the turn of the 20th century.  The Library of Congress has a number of his photos available online.  The fellow certainly was prolific – he seems to have captured a lot of governmental agencies at work during the Theodore Roosevelt administration, including Teddy himself.  It is possible that Fawcett was contracted to document the activities of the Fort Leavenworth schools and made postcards from some of the photos.

Someone was sweet on Miss Anna Williams.  Two of the cards were addressed to her. Her sweetheart must have decided that sending her pictures of muddy soldiers holding big sticks was the perfect way to win her heart. 2b3db-scan-014


– Brian

US Army FM 21-26

An Army field manual as a book of the month?  Just how interesting or relevant or important can a field manual be?

Well follow along, because for certain groups of people this FM is very interesting, relevant and important.

FM 21-26, Map Reading and Land Navigation is the Army’s map reading and land navigation handbook.  This manual has been in continuous publication and upgrade since 1941.  The current edition is dated 2005, with changes posted in 2006.  As part of a sweeping Army field manual re-designation the manual has been renamed FM 3-25.26*.  Regardless, it is still commonly referred to as FM 21-26, and that’s how we’ll refer to it here.

The Army seems to have adopted standard map reading and land navigation practices back in 1939, and published its first series of map reading and land navigation manuals in early 1941 (FM 21-25, Elementary Map and Aerial Photograph Reading and FM 21-26, Advanced Map and Aerial Photograph Reading).  Prior to 1939 map reading and land navigation was viewed almost as a black art, covered in non-standard texts targeted at officers and emphasizing field sketching and rudimentary survey as much as map reading and navigation.  A large part of the problem was that the Army had no map standards or centralized map production, so providing maps for unit operations was a local commander’s headache.  If you were a regimental commander and wanted a map of an area you put your regimental engineers to work either finding suitable maps from local or commercial sources, or you had them drawn up from field sketches or plane table surveys.

Army leaders realized that in the looming global war the old ways of producing and using maps would not do.  The Army needed dedicated map production assets that could produce millions of maps using common symbols, colors and scales.  This led to the creation of the Army Map Service and the standardization of map production on a global scale.  Once you had map standards in-place and maps in production you could develop standardized map reading and land navigation practices using these new maps.  FMs 21-25 and 26 were the result of that effort.  Finally, the Army had standardized map reading and land navigation texts it could use to train the millions of Soldiers about to be drafted into the Army to fight WWII.

After WWII, the establishment of NATO and the US Army’s realization that it would still maintain global warfighting responsibility the two field manuals were combined into one – FM 21-26, Map Reading, published in 1956.  The significant change in this manual was the introduction of the Military Grid Reference System (MGRS) based on the Universal Transverse Mercator (UTM) coordinate system.  The development of UTM and MGRS signified a revolution in mapping and mapping grids.  For the first time an army had an accurate low distortion world-wide grid system suitable for large scale mapping.  With MGRS and using just a paper map and a simple protractor a Soldier could uniquely identify his position anywhere on the face of the earth to within 10 meters.  MGRS is accurate, easy to teach, easy to use and virtually ‘soldier-proof’.

Updates to FM 21-26 came out every few years and the major changes seem to have been the simplification of basic principles and techniques, and the dropping of out-of-date or no longer needed procedures (like interpreting hatching to indicate landforms or the use of obsolete equipment).

Today’s FM 21-26 is map reading and land navigation distilled down to the basic, easy to learn and easy to execute functions.  It is not just map reading, but it is also the use of map substitutes (mainly aerial and satellite images), dead reckoning, field expedient direction finding, basic orienteering, terrain association and basic field sketching.  One key item of note is the Army’s method of teaching how to determine the magnetic to grid declination factors.  The lesser or greater angle method is hands down the easiest way to manage this often confusing issue.

Sure, FM 21-26 has a military focus.  It is, after all, an Army field manual.  The book spends a lot of time discussing the use of the MGRS system, how to orient, plan and navigate using MGRS.  It’s MGRS, MGRS, MGRS.  For years civilian students of map reading and land navigation had no use for this portion of the manual.  Topographic maps of the US either had no grids or had grids different than the MGRS grid, and US-based maps were printed at scales different than those used by the military.  This has all changed.  In just the past few years the US has (finally!) adopted what is known as the US National Grid.  The US National Grid is now being implemented for all USGS (US Geological Survey) large scale (1:24,000 and 1:100,000) topographic line maps, and the USGS is rushing the new US Topo series of maps into production.  So what is this new US National Grid?  It is nothing more than MGRS implemented for all USGS topgraphic maps of the US.  Remember, MGRS has always covered the world, but the US military does not produce maps of the US – that’s the job of the USGS.  The MGRS grid template always existed for the US, but the USGS never adopted it.  Until 2008, that is.  Driven by homeland security and disaster relief coordination concerns the USGS formally adopted MGRS, known as the US National Grid in the US, and is now producing maps to that standard.

Suddenly the discussion of MGRS in FM 21-26 becomes very relevant.  All the MGRS-based map reading techniques can now be directly applied (and are intended to be applied) to the new USGS topographic maps.  The only remaining issue is that of scale.  The US military produces large scale maps at 1:50,000 while the USGS produces large scale maps at 1:24,000.  While all the MGRS techniques apply to USGS maps, you can not use the standard map protractor (GTA 5-2-10) discussed in FM 21-26 since it does not have a 1:24,000 plotting scale included.  This isn’t a real problem because a number of manufacturers offer MGRS/US National Grid plotting scales for use with 1:24,000 scale maps.  One of my favorites is the Super GTA tool produced by

Another great thing about FM 21-26 is that it is one of the few Army field manuals authorized for unlimited release.  This means the Army retains the copyright to the manual, but users are free to copy, reprint and distribute it without penalty.  As a result you can find free downloads of FM 21-26 all over the web and you can purchase inexpensive printed copies from retailers like

So, if you like maps, are interested in map reading and land navigation, or have just a passing interest in these topics go get yourself a copy of FM 21-26!

– Brian

*The new designation of FM 3-25.26 seems a little unusual in the overall scheme of revised manual numbering.  I’d like to think that someone in TRADOC with a respect for military history recognized the significance of the original series of manuals, FM 21-25 and FM 21-26, and as a nod to tradition decided to redesignate the new manual as FM 3-25.26.