Xref: utzoo rec.radio.amateur.misc:3451 sci.geo.geology:488 comp.graphics:18435 rec.games.programmer:3962 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!hplabs!otter.hpl.hp.com!hpltoad!hpinddr!richv From: richv@hpinddu.cup.hp.com (Rich Van Gaasbeck) Newsgroups: rec.radio.amateur.misc,sci.geo.geology,comp.graphics,rec.games.programmer Subject: Formulas for projections Message-ID: Date: 5 Jun 91 11:14:21 GMT Sender: news@hplb.hpl.hp.com (Usenet News Administrator) Followup-To: rec.radio.amateur.misc Distribution: usa Organization: Hewlett-Packard, Cupertino, CA. Lines: 21 Nntp-Posting-Host: anorman.hpl.hp.com I would like to play around with a couple of different projections. Specifically I would like to create an azimuthal equidistance X-window of the earth from a country outline database. Would anyone have a formula handy for translating lat/long into x/y coordinates? I'm also trying to create whatever projection you would call "looking at the earth from the moon". I think I can figure this out if I think about it some more, but the azimuthal equidistance projection is beyond me. Perhaps someone can suggest a reference text on the subject. (Not general computer graphics, but specifically covering the bizarre transformations cartographers use to draw a 3d globe onto a 2d piece of paper). richv BTW azimuthal equidistance projections look really weird but are handy in amateur radio to determine which way to point directional antennas.