NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: HP 48GX Sight Reduction Programs
From: George Huxtable
Date: 2001 Oct 07, 1:20 AM
From: George Huxtable
Date: 2001 Oct 07, 1:20 AM
Lee Martinwrote about implementing Meeus' algorithms and other almanac / sight reduction programs on the HP 48/49 range. He added- >Perhaps we should take this discussion off List?? Others who may be >interested can follow. My comment- I would prefer any such discussion to remain on the list and not be shunted off. There may well be others who have implemented Meeus' algorithms on other machines in different ways who would be interested and may have something to offer. RPL (Reverse Polish Logic), as used in HP machines, presents its own problems of incompatibility with other software. My own implementation of Meeus' stuff (on the Casio FX730 programmable pocket calculator, now sadly unavailable) uses the Bastard-Basic peculiar to that machine, which has its owm limitations. Given the basic algorithms so usefully put together by Meeus, there are many choices to be made in implementing them, that are rather independent of the details of the language that is used. There's a community-of-interest here which it would be a pity to exclude. Though tricky to progrem, I have found that my old Casio does the job well. It has two problems. Its slowness: it takes around 5 minutes to provide a position of the Moon, or Jupiter or Saturn (these are the worst cases). And its inability to communicate with another computer. There's still some development going on here, using this old Casio, in terms of adding the ability to compute and reduce lunar-distance observations to provide a measurement of GMT. This is turning out to have somewhat more complexity than I expected (where have I heard that before?). If others show an interest in lunar-distances for longitude then I will start a thread going on that topic. George Huxtable. ------------------------------ george@huxtable.u-net.com George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. Tel. 01865 820222 or (int.) +44 1865 820222. ------------------------------