Hello
What are you doing ??
first if you use a gps you get WGS84 coords (lat, long)
This are degrees!, not meters, feet or something
What you have to do
1: make from the lat/long XY in your projected coordinate system,
2: here you can add/substract the coords out of the distcance measure
For the proper formulas just google, it is all out there.
be aware that lat / long is not equal lat/long
there are many systems, it can difference as much as 100 meter
Success
Greetings Olaf
freeman.matt@[EMAIL PROTECTED]
schreef:
> So I posted this thread over in the Bentley groups last week, but no
> responses and I'll give it a shot here...
>
> My group does a lot of mapping using Geographics, a GPS (which returns
> lat and long) and a rangefinder (which returns distance and bearing and
> heading). The five datums are written into a log file for each point we
> want to plot on a drawing. I've been tasked with writing a program
> which will read this logfile, im****t the base lat and long coordinates
> into geographics, and then offset the coordinates using the distance
> and bearing information from the rangefinder.
>
> At this point, I can break the log file entrties into the individual
> components (lat,long,dist,bear,inclin) and place these points in the
> drawing in the following manner...
>
> CadInputQueue.SendCommand "Place Point" CadInputQueue.SendCommand
> "Gcoord point " & Longitude & "," & Latitude
>
> I am also able to use trig and solve for the appropriate X and Y
> displacment like this...
>
> Angle = Angle * 3.14159 / 180
> Xdisp = Cos(Angle) * Distance
> Ydisp = Sin(Angle) * Distance
>
> Unfortunatly, this is where I run into trouble. If I simply do it like
> this...
>
> CadInputQueue.SendCommand "Gcoord point " & Longitude + Xdisp &
> "," & Latitude + Ydisp
>
> ...Geographics interprates the X and Y disp variables as degrees
> instead of feet. Needless to say, this tends to skew the offset by a
> few million feet instead of the hundred or so desired.
>
> If anyone has an idea as to how I could select the actual coordinate
> points of the last thing drawn or run the geographics coordinate
> conversion in a way to return the coordinates in a manipulable form, or
> anything that would work, please let me konw.
>
> Thanks in advance.
>
> -Matt
|
