In this video, I’ll quickly show you how to determine the bearing (direction of travel) from 2 points using paper & pen. At the end, I’ll show you how to get the same as answer on your GPS. This is part 2 of my previous video on using UTM to measure the distance between 2 waypoints.
Much like the previous video, you simply have to continue with your trigonometry skills from high school and determine the angle that you want to calculate.
In order to solve this, we do the first step which is to substract the easting & northing. So, in this example, we’re using coordinates for the Halifax citadel (P1) and ives point (P2), two military fortifications used up to WWII.
Now P1 453995 4943961
P2 457154 4940993
Now we use the math function Arc Tangent to solve this
Since the direction of travel is south, we need to do a final calculation of (180-47)= 133 degrees. To verify this final answer, simply grab your compass and determine the bearing on the map.
In our example, I got 131 degrees, but if I had larger scale map, I probably would have gotten closer. Then finally we used our garmin gpsmap62 and used our map page to determine that the bearing from P1 to P2 is 133 degree, matching our paper result.