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View Full Version : Help with Map 3d Setup

terpsguy
21st Mar 2009, 07:33 am
Trying to set up Map 3d 2009. Please have patience, until 2 weeks ago, I hadn't used ACAD since I had my last monochrome monitor (many, many versions ago) so I am still learning the basics. I understand how to use most of the drawing tools, however, I am having several issues setting up the basic template.
I need to set up the drawing to use lat/longs vice Cartesian/Polar coordinates (display and input), set the angle direction control to N0/E90/S180/W270 and scale the drawing to specific map scales (i.e. 1:24000 (1"=2000')).
I have assigned LL84 (WGS84) datum to the drawing and drew a line representing a runway at 36.13361389/-86.65927778 to 36.11271317/-86.66764320. The distance between the points should be right on 8000'. I set the units (Setup>Formatting Options>Units) to feet, however the distance tool still shows 0.029 between the points and the geodetic distance shows 7608.8135' which is a much greater difference than you should see over this short distance with earth curvature. Also, ACAD appears to be rounding the L/L to 4 decimal places (which probably accounts for the 400' difference) and I need at least 6 (preferably 8 ) for accuracy standards. Regarding the azimuth, I checked "clockwise" in units and selected North in the directions window but the azimuth still shows E0/S90/W180/N270. I also tried setting the North direction from Y axis to 0 in the COGO setup window which did not seem to work either. My primary need for the azimuth is for ACAD to display the azimuth based on 360 deg clockwise with N=0. Any assistance you all can provide would be much appreciated. Thanks in advance.

terpsguy
23rd Mar 2009, 03:35 am
Ok, I have managed to solve (or narrow down) most of my issues on my own. I re-entered the lat/longs in a new dwg and the geodetic distances are now accurate on all four runways at the airport. However, it seems that the issue with the distance displayed is that when I specify LL84 (WGS84) as the coordinate system, it defaults the units to "degree" with no apparent way to change this. Does anyone know how this could be changed? I specifically need the units to be feet for use on offset and azimuth/distance functions. Regarding the azimuth settings, when I go to the properties box, the azimuth (angle) displayed is correct, it's just when I am drawing that the angle displayed is still based on E0/S90/W180/N270. Again, any assistance is very much appriciated.