- 1). Locate a reference point directly behind the target object, such as a radio tower or mountaintop.
- 2). Move directly to the left or right with respect to the target object until there is a measurable angle between the target object and the reference point.
- 3). Measure the angle between the target object and the reference point using a compass or telescope cross hair. This is the parallax angle of the target object.
- 4). Measure the distance between your original location and the new location.
- 5). Convert the distance to the unit of distance in which you want to measure the target object. For example, if you moved 20 feet and you want to measure the distance in miles, convert the feet to miles by dividing by 5,280 to get 0.0038 miles.
- 6). Plug the distance and parallax angle into the formula D = (360 * X) / (2 * pi * A), where X is the distance you moved, pi = 3.14159 and A is the parallax angle. For example, if you moved 0.0038 miles and the parallax angle was 0.5 degrees, plug the values into the formula to get D = (360 * 0.0038) / (2 * 3.14159 * 0.5) = 0.43 miles.
previous post