I don't know where you live, but there is one reason it won't work: overcast sky! It usually happens when you wish it wouldn't, isn't it?
So, a nice (if dull) all-weather solution is to buy your wife a simple... compass! (It's funny that nobody came with this simple and effective solution?). The 30° accuracy can probably be obtained with the key-chain type (~3$) while standard types (~25$) should easily provide 5° accuracy. At least it's cheaper than a new car with one built-in... ;-) In the mid-range, there are also neat compass-watches. Now, if you insist for the Palm hi-tech solution for sunny days, there are programmes that do exactly what you suggest: a nice one is Planetarium, by A. Hofer: http://www.aho.ch Cheers, Thierry 50.5 N (overcast) 4.3 E Steve Turley wrote: > > Esteemed list... > > My wife is a realtor who often wants to determine the direction a house > is facing. Being directionally impaired, and not having a car with a > built-in compass, she is usually at a loss. I had the idea, not > especially original or brilliant, of writing an anti-sundial for her > Palm PDA. My idea is that, given the time and approximate location and > knowing the position of the sun, we should be able to determine which > way is North. I was thinking of a program that would draw a compass rose > and display a marker showing the sun's position. She would then rotate > the Palm until the marker pointed at the sun and, voila, the rose would > be oriented properly. Accuracy of +/- 30 degrees is adequate. > Any reason this won't work? > And, since I'm mathematically lazy, can someone tell me how to do the > calculation? > > Thanks. > > - -
