Ian, The further the distance, the less accurate it needs to be. So +/- 1 degree is probably the best way to represent the accuracy I need. e.g. roughly +/- 1.7km @ 100km and 1.7m @ 100m etc.
Cheers Tim -----Original Message----- From: SCISOFT [mailto:[EMAIL PROTECTED] Sent: 02 July 2004 10:15 To: Tim Smith; 'Nielsen, Erik R' Cc: [EMAIL PROTECTED] Subject: RE: MI-L New lat/long from distance/bearing Tim What sort of accuracy do you need? You talk about less than 100km distances, but is accuracy to +/- 20m or to +/- 1m what you can tolerate? Ian Thomas GeoSciSoft - Perth, Australia > -----Original Message----- > From: Tim Smith [mailto:[EMAIL PROTECTED] > Sent: Friday, 2 July 2004 4:57 PM > To: Nielsen, Erik R > Cc: [EMAIL PROTECTED] > Subject: RE: MI-L New lat/long from distance/bearing > > Erik, > > Thanks for your reply. > > I am also working over small spaces (< 100km area), so I could use > normal trig as you mention. But I must first convert the lat/long to a > meter grid because my distance is in meters. This is because X2= x1 + > L > * sin(ang) will mean nothing if x1 is in decimal degrees and L is in > meters. > > Kind regards > > Tim > > -----Original Message----- > From: Nielsen, Erik R [mailto:[EMAIL PROTECTED] > Sent: 02 July 2004 09:43 > To: Tim Smith > Subject: RE: MI-L New lat/long from distance/bearing > > > Tim, > I've been following this with interest. I don't know MapX that well > and I'm normally working with smaller areas, that can be assumed > euklidean spaces (even if in lat-long). I liked Uffe's link, and those > calculations should work fine. Sorry not to be of more help. Cheers > Erik > > > -----Original Message----- > From: Tim Smith [mailto:[EMAIL PROTECTED] > Sent: 02 July 2004 09:36 > To: [EMAIL PROTECTED] > Subject: RE: MI-L New lat/long from distance/bearing > > > Hi Erik, > > This is fine. But I need to know how to convert from WGS84 lat-long > into a meter grid so I can do the trig. > > Tim > > > This email and any attached files are confidential and copyright > protected. If you are not the addressee, any dissemination of this > communication is strictly prohibited. Unless otherwise expressly > agreed in writing, nothing stated in this communication shall be > legally binding. > > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please visit http://www.messagelabs.com/email > ______________________________________________________________________ > > > X2= x1 + L * sin(ang) > Y2 = Y1+ L* cos(ang) > > Or switch sin or Cos if it doesn't look right, don't test with 45 > degree angle, test with zero or 90. Best regards Erik > > -----Original Message----- > From: Tim Smith [mailto:[EMAIL PROTECTED] > Sent: 29 June 2004 15:56 > To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: RE: MI-L New lat/long from distance/bearing > > > Hi, > Thanks for people who have helped so far with this, > > I want to draw a line in MapX between two points. The function in MapX > to do this takes two WGS-84 lat/long points. I don't have two lat/long > points. I have one lat/long, an angle in degrees and a length in > meters. I need to calculate the second lat/long (unless there is a > MapX function that can draw a line - given a position, angle and > distance). > > A C++ algorithm to do it would be fine. I can't believe MapX doesn't > support such a calculation. > > Tim > > > > -----Original Message----- > From: Terry McDonnell [mailto:[EMAIL PROTECTED] > Sent: 29 June 2004 15:42 > To: Tim Smith > Subject: RE: MI-L New lat/long from distance/bearing > > > Is your problem what algorithm to create to do this or how to do it > Mapx or code it in C++? IOW do you not know how to go about it? > > Terry > > -----Original Message----- > From: Tim Smith [mailto:[EMAIL PROTECTED] > Sent: 29 June 2004 12:42 > To: [EMAIL PROTECTED] > Subject: MI-L New lat/long from distance/bearing > > > Hi List, > > I have a latitude and longitude in WGS-84. > I want to calculate a new point based on a bearing and distance from > this position. > > Difficult bit - > I want to calculate this using MapX, or alternatively I could use some > C/C++ code. > > Thanks for any help with this > > Kind regards > > Tim Smith > > --------------------------------------------------------------------- > List hosting provided by Directions Magazine | www.directionsmag.com | > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > Message number: 12390 > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please visit http://www.messagelabs.com/email > ______________________________________________________________________ > > --------------------------------------------------------------------- > List hosting provided by Directions Magazine | www.directionsmag.com | > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > Message number: 12395 > > > This email and any attached files are confidential and copyright > protected. If you are not the addressee, any dissemination of this > communication is strictly prohibited. Unless otherwise expressly > agreed in writing, nothing stated in this communication shall be > legally binding. > > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please visit http://www.messagelabs.com/email > ______________________________________________________________________ > > --------------------------------------------------------------------- > List hosting provided by Directions Magazine | www.directionsmag.com | > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > Message number: 12431 ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. 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