确定对象是否远离某个点而朝着某个点移动

Question

I am trying to practice my skills with using latitude and longitude and I'm attempting to determine the following: given a center point X on a map and a point around it called Y, how do I tell whether or not the points around the center are moving away from the center object or towards it using latitude and longitude?

Right now I have the center latitude and longitude and am focusing on one of the points around it. I have used the Haversine method to calculate distance in miles between two lats and longs. Using this I measured the initial distance the from X to Y and assigned it to a variable. Upon Y's first move I recalculated the overall distance from X to Y and compared it with the initial. If the new measurement is greater than the old then your distance from the point X is increasing, if not it's decreasing. Also, I have check to make sure what I'm working with the point Y is ACTUALLY moving some distance with each move, not just going around the radius of point X in some weird fashion.

Is the way I'm doing things sound alright? I keep feeling like I need to fine tune something but I just can't put my finger on it.

Hopefully everything I'm saying makes sense and is not falling on deaf ears and this doesn't get flagged as an non-constructive question. It definitely is.

Answer 1

Yes, this is the correct way, I have done this some years ago:
In praxis you get the coordinates from a GPS device. Therfore you may consider additional filtering, eg ignore situtions where the device stands still. Because this may introduce positional jumps. In your question I saw that you already use a filtering by distance moved: this is suitable!

You can use the haversine formula, like you propose. For high load situations, there are faster distance formulas, for your task (small distances), which do not need so much trigonometric calls, but this is a minor topic.