Care and feeding of the Total Station

You’ve probably seen pictures of archaeological digs with grids made of strings. Much of what we can learn from a site comes not just from what artifacts are found there, but from where particular artifacts are found in relation to each other.  The string grids are there to make it easier to record where each artifact is found (what archaeologists call “provenience”). I rarely use them.

Many years ago, my husband Glenn Sheehan (also an archaeologist) went to a talk at the Engineers’ Club in Philadelphia, where Harold Dibble & Shannon McPherron demonstrated a system to record provenience in 3 dimensions using an electronic total station (used by surveyors) connected to a palmtop computer (back then, an HP 95) to record not only the place each artifact was found, very precisely and with no transcription or data entry errors, but also some information about it. It automatically assigned an individual artifact number. There was even a little thermal printer that made tags to put in the baggie with the artifact! I left determined to get one.

We did, and took the system to places it had never been. Harold and Shannon had developed it for work on French Paleolithic sites, which tend to be very small. We wanted to use it on bigger sites. Fortunately, they kept improving the program, and it’s now really flexible. You can define what data is collected, set up menus, and use it on really huge sites.

Figuring out how to make everything work in the Arctic, where cold kills batteries and you can’t just plug into a wall socket was another adventure. A combination of generators, chargers, adaptors, and gel cell motorcycle batteries solved that problem. I got pretty good at repairing wires on adaptors, since the original stuff couldn’t take cold.  Over the years, the HP95s have been replaced with rugged laptops, and the thermal printers died. We haven’t found a good replacement for printing bag tags, but old-school marking the bags with a Sharpie works fine.

The GTS201D and all its equipment at Nuvuk.

Of course, the whole system depends on the total station. I’ve got 2, a Topcon GTS3B and a Topcon GTS201D, which is supposed to be waterproof. Total stations are surveyors’ instruments, so they are built to be moved around a lot without loosing accuracy, but they do need to be recalibrated on occasion. That time came for the 201D after last season.

Now, the only place in the state of Alaska that this can be done is in Anchorage. The 201D came in a case with really fragile fasteners, which have not held up well, and I haven’t been able to find a replacement, so we actually lash the case closed like a birthday present.   Needless to say, I wasn’t interested in shipping or mailing the total station down to get calibrated. But Laura and her husband Brian were going to Anchorage, and I was going down several weeks later. I called the shop, and they said the work could be done in the time between the trips, so they hand-carried it down and Brian dropped it off. They assured Brian the work would only take a week or so.

I went down for the Alaska Anthropological Association meetings & medical appointments a few weeks later and stopped by to get it, only to find it wasn’t done. What they had forgotten to tell Brian when he dropped it off was that one repair tech was on vacation and the other was out-of-state for two weeks of training, which had backed things up at bit. They couldn’t get it done in time for that trip. A few weeks later, I went to the Society for American Archaeology meetings in St. Louis.  Since you can’t get anywhere in the Lower 48 from Barrow without going through Anchorage, I was able to pick the total station up on the way home!  It’s now safe and sound in the lab, waiting for the fieldwork to start.

One thought on “Care and feeding of the Total Station

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s