2D/3D Map Scale in RCAD

Dear Shuhai Zheng :

There are times when you may run into map data that has different unit bases for X-Y data and elevation data. For example, USGS DEM files have their X-Y coordinate data in UTM (Universal Transverse Mercator) units (which are metric coordinates), whereas the elevation component of the DEM data is often in feet.

Note that the 2D/3D Map Scale and 3D Elevation Scale configuration entries in the Configure Topo Map dialog box can be used to specify unit conversion factors so that the cross-section geometry that is cut from topo map is in the same unit base for both X-Y and elevation data.

To convert meters to feet, a scale factor of 3.28084 should be used. To convert feet to meters, a scale factor of 0.3048 should be used. Therefore, to create cross-sections in feet from a USGS DEM contour map, a scale factor of 3.28084 should be specified for the 2D/3D Map Scale entry. Similarly, to create cross-sections in meters, a scale factor of 0.3048 should be specified for the 3D Elevation Scale entry.

If you have any additional questions or need any further information, please contact me again.

Sincerely,

Chris E. Maeder, M.S.
Senior Technical Engineer
chris.maeder@bossintl.com

Dear Chris:

I talked with you about this subject before, but I like to get your answer
one more time.

Enclosed please find a DXF file, which is created from tagging 1:24,000
USGS paper quad. This tagged vector coverage (TVC) was projected in UTM
NAD83. A GIS specialist created the DXF file for me. As I understand, the x
and y are in meters and the z is in foot.

My work is to cut cross-sections from this DXF file, and then compute flow
depth in English units.

After I opened the DXF file, how should I configure it (especially Topo Map
Configuration) before cutting cross-sections?

I would really appreciate a configured file (.FLX) in RCAD, and three
cross-sections cut at those marked locations. So I confirm if what I have
done is correct. BTW, those annotations are section number, invert
elevation, discharge, and slope (in clockwise).

Thanks in advance!

Shuhai