My lapless laptop.

In the Fall of 2003 a friend of mine asked me if I would be interested in mapping a civil war battlefield for a preservation organization.  He knew that I was interested in maps from some work we had done earlier.  I was very interested but didn't have the right equipment.  So, my first thought was to go on line and locate the companies that sold the equipment.  Turns out virtually everyone buys their GIS mapping equipment from Trimble.  I found and visited a local sales office and to my surprise the basic equipment one needs starts at approximately $6,000 and goes up from there to a really nice system at around $22,000.  This includes all of the hardware and software required for both the field work and office work to produce and display a map.

Well, I'm not the $6,000 hobby type so I started to look for alternatives.  Since software appeared to be one of the largest single cost items I went looking for an alternative to the packages available from the majors, ESRI and Mapinfo.  I found a package advertised as fully functional, Manifold, that sells for around $400.  It got good marks in the forums and I had about decided that I would cough up the $400; but before I did I needed to make sure I had a hardware setup for the field work.

So, my next step was to visit the Internet to see what was available.  I found almost no solutions.  I did find a number of forum entries asking for setups that could be used about the way I wanted, but no solutions.  I searched under lapless, figuring that I could use my laptop for the field work if I could figure out how to use it without having to hold it.  No luck... I looked under wareable, hands free and every other combination I could think of without any usable hits.  Usable had to mean affordable; say under $500 or so. 

The break through came when I was explaining to my wife what I was trying to do and she suggested I look under "drum carrier".  That did it.  After visiting several band equipment websites and seeing that new ones sold for $80 to $150 I visited eBay and started bidding.  I got a snare drum carrier for around $40.  It was in excellent shape.

I added the padding since there are two bolts that hold the pieces together and I wanted to prevent any problems in long field sessions.  Next I had to figure out a way to secure my laptop to the carrier.  That turned out to be easy.  I purchased a sheet of Plexiglass and a couple of metal angles.  I secured the Plexiglass to the angles and the angles fit nicely into the piece of the drum carrier that fit over my hips and I secured it to the bottom holes at left.

I used a standard IBM port expander for my Thinkpad 385 XD and secured it to the Plexiglass piece with Velcro.  At this point I had to get a more accurate Global Positioning System (GPS) than the Garmin 45 I regularly use for my trips.  Once again I went to the Internet and started looking.  The best deal appeared to be a new model that Garmin was about to go on the market with a GPS 18 PC.  It's an OEM GPS that is about the shape and size of a hocky puck.  It's black and has a couple of wires coming from it; that's it.  It's WAAS enabled; so I can get better than 3 meter accuracy.  I found a site on the Internet that had them for sale for about $90.  It came in a box with no instruction book or anything else; just the GPS.  At the time Garmin claimed they had not started shipping them yet so did not have an on line instruction book available.  This turned out not to be a problem.  I hooked it up; plugged it into a power supply and my laptop and it immediately started sending messages, standard NMEA sentences.  Using software I had written previously I mapped all the sentences.

Next I needed a way to secure the GPS for field operation.  Once again I looked for available antenna masts for a GPS.  Turns out they're quite expensive as well.  So, I bought a piece of PVC tubbing, a junction box and a couple of connectors and fashioned a device that serves nicely as an antenna mast.  The bottom of the GPS is magnitized; so I added a metal plate to the top of the mast and that secured the GPS.

As a power supply for the GPS I used an emergency car battery power supply.  It had the cigarette lighter adapter that the GPS required and could be recharged with an extension cord and 115 volt power.  I had to shape the top of the junction box to fit the bottom of the power supply using a file and added a velcro strap to secure the power supply to the junction box.

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At this point I had all the hardware I needed and wanted to try it out in the field before springing for the $400 for the software.  I scheduled a trip to central Virginia and loaded up my truck with the whole setup.  Once on the battlefield I suited up and walked around the field taking readings on my laptop with my map-following software.  I saved the track that I paced out figuring I could use it to gauge the precision of the new GPS.  Everything worked fine.  Although both my hands are free to use on the keyboard or mouse or whatever the whole setup is a bit unwieldy.  So, I went out and bought one of those extendable metal walking sticks to use as a third point of contact. 

So, now all I lacked was the software.  Upon return I revisited the Manifold site and they were still saying $400 for the package.  I took one last shot at freeware and still couldn't come up with anything but I did find out that ESRI will allow anyone to download the viewer for their map software; just need to pay for the part of the software that will allow you to make a map.  In researching this a bit further I found that one of the standard files used for map layers is a "shape" file.  I went looking for the specifications for shape files.  It is a standard file, actually three file types that make them up.  I down loaded the specifications from two different sites and attempted to turn my saved track into a line shape file.  After lots of work I was able to do it.  As a result using the ESRI viewer I can load lots of map layers plus my line shape file into their viewer and end up with a nice map.

I've decided not to spend the $400 for Manifold.  I'm about 25% complete in writing my own Windows version of the field piece of the mapping software.  When done it will handle 8 shape types, point, multipoint, line, polygon and z versions of each. 

  Total estimated cost of the hardware: