I have been getting disappointing results from BearingDistanceToLine_management in v10.0 when using a Polar Stereographic projection.
In, for example, the upper right quadrant (where the pole is to the lower left), feeding the tool a direction of, say 14° (measured clockwise from the y axis), plots the line traveling from the start point in a direction 14° clockwise from the direction of the pole (at 0,0)!
This behavior is rather less than useful.
I have tried feeding the spatial reference as a spatial reference string in a python script, and by Importing it from another feature class in the tool interface, with the same result either way.
The projection is:
Projection: Stereographic_North_Pole False_Easting: 0.000000 False_Northing: 0.000000 Central_Meridian: 180.000000 Standard_Parallel_1: 60.000000 Linear Unit: Meter (1.000000)
or, if you prefer: 'PROJCS["WGS_1984_Stereographic_North_Pole",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Stereographic_North_Pole"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",180.0],PARAMETER["Standard_Parallel_1",60.0],UNIT["Meter",1.0]]'
As I was doing it then (I have since developed a work around that does not use the BearingDistanceToLine tool), I had two sets of points: one that represented the start point and the other that was a dummy end point. (so I could get the angle I wanted even if the length was wrong) These were originally plotted in lat / long, and then projected to the stereographic space. I used AddXY to get the locations of the start points, and used NEAR to get the angle between them (from start to end) I had used Near on selection layers that each only contained one point: each of the matching pair, so there was no confusion about which point pairs I wanted to know about. From this I recieved an angle, albeit one measured counter-clockwise from the x axis (as NEAR is advertised to deliver). I subtracted that angle from 90 to get an angle rotated clockwise from the y axis (as I understand BearingDistanceToLine wants). I had calculated the desired distance in meters earlier.
I used the POINT_X and POINT_Y from AddXY in Stereographic for the origin (and the resulting lines start in the right place, so that is okay) I used my previously calculated length for the length (this came out fine too) and I used the 90° - NEAR_ANGLE value for the direction (and this was funky)
I tried using some other angles too. It has since occured to me to try using the same angle for all the points (scattered across the Arctic), but I have not done that yet.
2. It is a valid expectation that the tool could support an option for the Bearing values to be measured from the Y-axis. If possible, could you describe what the use case is - what is the theme you are trying to map or the analysis you are trying to do? This information would be helpful in justification for the new option/parameter.
Thank you very much for posting the question and workaround. I will follow up with these enhancements. Let me know if you have further questions or suggestions.