July 21, 2003

Celestial Navigation

Another pastime I thought we could amuse ourselves with in the Outback was to spend the nights learning how to fix our own position using the stars, Len Beadell-style. His books don't especially explain how to do this, but he did mention the use of compasses, theodolites, and lots ot tables.

So yesterday I put out a query on sci.engr.surveying and sci.geo.satellite-nav

Wow... I got a lot of responses.

Hard to summarize them.

A sextant is the "cheap" way to do position calculation. However, it's better suited to the sea because you can see the true horizon, while on land you have to make a fake horizon by using a pan full of oil to reflect the stars. Sounds like if you know what you are doing, you can get to about one mile accuracy.

A theodolite is better suited, but even the Kern DKM1, a reliable mechanical relic of the 70's still used, is at least several hundred dollars, more likely "under $1000." Ouch.

One interesting idea was to get some of the more powerful astronomical software out there, . They say simply by careful observation of the night sky as you see it, plus time-of-day, plus date, you can back-calculate your position to within thirty miles. Not that this is great, but it is even just a fun exercise to pick out the Southern Sky features. We could buy quite a set of telescopes and binoculars for less than $1000...

The thing is, if we could beg, borrow, or steal a theodolite, there is tons of info on the web about how to navigate using them. So we need to start asking around to see what we can find. Matt -- check your engineering department. Dad -- check your plant colleagues (or maybe Nick). Mom -- call up Howard. Shannon -- you are in construction...can you help us?

It also might be worth calling up an equipment rental place -- these things must be rentable...

Posted by Nils Blutig at July 21, 2003 01:56 PM | TrackBack