I would like to enter a series of points along a certain angle in ArcMap. I have a UTM coordinate as a starting point, and from that I'd like to enter 10 points at a 120 degree bearing every 50 meters. What is the best way to do this?
From the context menu while digitizing a new line I would use Absolute X,Y to enter the coordinates of the start vertex and Direction/Length to do the second (and last) vertex 120 degrees and 500 metres away.
You then have a selected line which is ready for Construct Points which "creates new point features at intervals along a selected line".
perhaps draw the line using the create features tool. right click for angle/bearing (can't remember) and put 120 degrees. Then right click and hit length, enter 50 meters. This will lock your draw feature tool into a 50 meter line at 120 degrees. continue this 10 more times then use Data Management > Features > Feature Vertices to Points.
There is probably a better way but this should work
This seems like a simple trigonometry task, perhaps excel is the easiest approach. You should be able to set up a simple recursive spreadsheet using the equations below.
Assuming your 0 degree line coincides with the positive direction on the y axis then:
x1 = x + 25
y1 = y + 25*sqrt(3)
Where (x,y) is the coordinates of your starting point and (x1,y1) give you the first point. Now just repeat 49 more times :)
You can use the Direction-Distance tool from the Editor toolbar:
The tool creates a point using a distance from a known point plus a direction from a known point to define a bearing line.
A step by step instruction can be found in ArcGIS help.