From:    Ernest Williams 
Subject: SUMMARY for lat/long transformations

ECOLOG folks,
After posting the following message, some people requested that I pass
along the replies back to the list, so here they are, somewhat edited.
Many thanks to all contributors; the replies helped me solve my problem.
This reflects the power of the web.
Ernest

Date:         Mon, 24 Jan 2000 13:29:15 -0500
I'm looking for software that will:
1. transform continental-scale latitude/longitude data to x/y (Cartesian)
coordinates.
2. calculate the great circle distance between two points given their
latitudes and longitudes.
Thanks for helping.
Ernest Williams,
Hamilton College

_________________________________________________________
TWO PEOPLE SUGGESTED ARCINFO.
Date: Mon, 24 Jan 2000 14:50:27 -0500
=46rom: Petya Entcheva 
Hello, There is a very widely used software that ca do it: ArcInfo
ArcInfo has a good "help" pages, but I'll be happy to help if you'll like...=
=2E.
Petya
AND
Date: Mon, 24 Jan 2000 15:32:06 -0500 (EST)
=46rom: Jiong Jia 
The job will be easily done if Arc/Info and ArcView are combined. Good luck.
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=46rom: "Michael S. Batcher" 
Date: Mon, 24 Jan 2000 14:48:06 -0500
Check out this link and see if it helps. If I recall, there are two versions
of the software: a little one and a big one. I think the little one will
work for you, but you should read the web page. Good luck!
 http://crunch.tec.army.mil/software/corpscon/corpscon.html
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Date: Mon, 24 Jan 2000 17:38:13 -0200
=46rom: Friedrich Herms 
Dear Ernest
I have this simple dos program (attach) to transform coordinates. I hope tha=
t
this can help you.  Friedrich Herms  Oceanography Dept. - UERJ
Attachment converted: Macintosh HD:coord.zip (pZIP/pZIP) (0000AD04)
NOTE: PROGRAM NOT FORWARDED TO ECOLOG-L
_________________________________________________________
Date: Mon, 24 Jan 2000 15:17:09 -0500
=46rom: Sheryl Soucy 
In order to calculate great circle distances given longitude/latitude
coordinates, I used the following web site:
http://www.vwlowen.demon.co.uk/java/circle.htm
I'm not sure who runs the web site or what the intended purpose of the web
site is.  I somehow stumbled across it while looking for software to make
that calculation.
Peter Krafft in the geography department at Florida State University also
provided me with the formula for the calculation which is
Cos D =3D (sin A)(sin B) + (cos A)(cos B)(cos P)
D =3D arc distance between points A and B
A =3D latitude of point A
B =3D latitude of point B
P =3D degrees of longitude between points A and B
I think all of these terms have to be in radians instead of degrees.  I
never had to use this formula because I found the website first.
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=46rom: "james salierno" 
Date: Mon, 24 Jan 2000 14:00:57 PST
Dear Ernest,
You might want to check out the US Coast Guard web page. I downloaded a
program to convert loran coordinates to Lat/Lon. It may have what you need
as far as x/y cartesian is concerned,
Good Luck, Jim
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=46rom: "ROBINSON, JULIE A. (JSC-SN3)" 
Date: Tue, 25 Jan 2000 08:52:48 -0600
There are several javascript tools on the web for calculating the great
circle distance.
I use http://www.best.com/~williams/gccalc.htm
Good instructions (in the form of an FAQ) for how to do the calculations
yourself (e.g. in a spreadsheet) are at
http://www.census.gov/cgi-bin/geo/gisfaq?Q5.1
Spreadsheets to do both of the calculations you want (x/y and great circle)
can also be downloaded from the Australian Surveying and Land Information
Group.
http://www.auslig.gov.au/geodesy/calcs.htm
Hope this is helpful. Julie
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Date: Tue, 25 Jan 2000 09:59:23 -0700
=46rom: Mike Kearsley 
Ernest; I've attached a program which will (I think) convert lat long data
to UTM coordinates (which is a form of x-y that may work for you) and vice
versa.
Be aware that there are different versions of lat and long, and that you'll
have to choose one (I've always used International). I can't help you with
the great circle distance calculations. Mike
NOTE: PROGRAM NOT ATTACHED.  I USED IT SUCCESSFULLY, HOWEVER
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Date: Fri, 28 Jan 2000 09:18:55 -0700
=46rom: Mike Kearsley 
Ernest;
I found a web page with lots of information on free cartographic software:
http://kai.er.usgs.gov/ftp/PROJ.4/PD.projections.FAQ
The site is dated "1994" and includes lots of references to ftp download
sites, so some stuff may have changed, but there are links on the page
worth checking out (especially the GCTP freeware information).
Cheers, Mike    mike.kearsley@nau.edu
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=46rom: TA32@aol.com
Date: Tue, 25 Jan 2000 09:28:21 EST
Mr. Williams: You might try looking on the web page: www.wellston.com for
the software you  are looking for.  Wellston Technologies, Inc.  puts out
some very user  friendly software (windows based) for manipulating data
from GPS receivers, including downloading the data directly from the
receivers as well as
lat/long data handling capabilities.  They have some software on the website
that you can download for a free 30-day trial if you like.
Good luck, Tyler Abbott    tyler_abbott@fws.gov
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Date:         Sat, 29 Jan 2000 17:20:56 -0600
Reply-To: Jerrold Zar 
You might look at this paper: Zar, Jerrold H. 1989. Microcomputer
determination of distance and initial direction of great-circle paths.
Journal Field Ornithology 60:520-522.......
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Date:         Sat, 29 Jan 2000 19:13:41 -0600
Reply-To: Jonathan Stern 
ernest, you might check out matlab. it has a toolbox called 'mapping' that
does what you require very nicely. though i need to go check out dr. zar's
reference. i hope this helps. jon
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Date: Mon, 31 Jan 2000 00:06:03 +0100
=46rom: Michele Scardi 
Ernest, I wrote a Fortran program that transforms geodetic coordinates (I
mean lat/lon degrees, e.g. 38.5432=B0N 14.7865=B0E) to UTM coordinates using
the WGS84 datum. If you (or other ecolog-gers) want to give it a try, just
drop me a line. I can send you both the source and/or the executable. It's
a program I wrote for myself and I always used it within 2 UTM zones only,
but it seems that it works,
although it isn't exactly user-friendly.
You can also take a look at:
http://www.swcp.com/csar/UTMConverter.shtml
There's a nice Java UTM/Lat-Lon converter that can be useful
if you only need to convert a limited amount of data.
Point your browser to:
http://www.utexas.edu/depts/grg/gcraft/notes/datum/datum.html
or to
http://geography.hunter.cuny.edu/mp/
for complete info about coordinate systems and map projections.
I hope this helps, Michele
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Date: Mon, 31 Jan 2000 13:46:30 -0500 (EST)
=46rom: Robert Kenney 
The algorithm below will calculate great circle distances between pairs of
lat/long coordinates.  I pulled it out of one of my SAS programs, but the
syntax is pretty basic.  It uses lat/longs in radians, and the distance is
in kilometers.  Take out the 57.29578 factor to use lat/longs in degrees,
and take out the 1.852 factor to get distance in nautical miles. (Hi, Jon!)
     DISTANCE =3D 1.852 * 60 * 57.29578 * ARCOS((SIN(LAT1) *
                SIN(LAT2)) + (COS(LAT1) * COS(LAT2)) *
                COS(LON2 - LON1));
Cheers, Bob