Distance between geographic poimts - Printable Version +- HP Forums (https://archived.hpcalc.org/museumforum) +-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html) +--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html) +--- Thread: Distance between geographic poimts (/thread-110456.html) |
Distance between geographic poimts - Sam Levy - 03-18-2007 Around the HP-65 HP-67 era my boss had me calculate distances for his glider club. It was in the calculator book I was using, I shortened the program and made it automatic for crossing the equator. I have the manuals on CD and I request help finding that worked solution. If you could help me find the book and page please. Sam
Re: Distance between geographic poimts - Thomas Okken - 03-18-2007 I have an HP-42S program that computes Great Circle Distance here. Should be easy to adapt to the HP-65 or HP-67 or any other RPN scientific. dist = acos(cos(lat1)*cos(lat2)*cos(lon1-lon2)+sin(lat1)*sin(lat2)) Where dist is an angle on the Great Circle passing through the two points. Assuming the calculator is in DEG mode, multiply by 60 to get nautical miles, etc. This formula works for any pair of coordinates -- no issues with crossing the equator or passing over the poles or anything like that. UPDATE: There is more information, and more accurate formulae, here. - Thomas
00 { 101-Byte Prgm } Edited: 18 Mar 2007, 5:07 p.m.
Re: Distance between geographic poimts - Charles - 03-18-2007 Sam,
Try the "HP25 Applications Programs" book, pages 61-69
Re: Distance between geographic poimts - Jean-Marc - 03-18-2007 Hi, Re: Distance between geographic poimts - Sam Levy - 03-18-2007 Thanks to all. I had hoped to find the example I used before but I will be more adventurous and try one of the complex solutions. Sam
Re: Distance between geographic poimts - Les Wright - 03-18-2007 Are you referring to the programs in the Navigation Pacs for HP65 or HP67? Both of those manuals are on the DVD under the "Calculator Software Manuals" subheading.
Les
Re: Distance between geographic poimts - Les Wright - 03-19-2007 Actually, there is a simpler routine called Great Circle Navigation in the manual for the HP65 Standard Pac. That is on the DVD too. Maybe that is the one you are remembering? It just fits into the HP65's 100 steps.
Les
Re: Distance between geographic poimts - Les Wright - 03-19-2007 I would recommend this highly. Jean-Marc doesn't post nearly frequently enough on the Forum for my liking. I have become a huge fan of his work--indeed, most of my more recent programming efforts in special functions for the HP33S and 32sii are basically shameless plagiarisations of his stuff. His contributions are prolific and are almost always huge improvements over what has previously been available in the HP41 users' library solution books. Can you let us know if you ever locate the old program you were thinking of?
Les
Re: Distance between geographic poimts - Sam Levy - 03-19-2007 First my surprise at finding my own entry in this forum on Google search for Kinpo. Second the equation I used must have been in a calculator manual as I did not buy any other texts or programs. Re: Distance between geographic poimts - Jean-Marc - 03-20-2007 Hi Les,
( sin(d/2) )^2 = ( sin(b-b')/2 )^2 ( cos(L-L')/2 )^2 where L , L' = longitudes and b , b' = latitudes
These formulas are less accurate than Andoyer's formulas,
Actually, d/2 is in X-register at line 30 of the "TGD" program
Regards, |