Calculating standing times

Question

I have n objects and each object has m positions.

Every position is defined by x, y (in millimeters) and a (unix) timestamp.

{
  objId: 'a-b-c',
  x: 123,
  y: 567,
  date: 123456789,
}

Now I want to calculate how long an object didn't move.

My first algorithm always updated a list of "last" positions for every object if it got a different position. If the new position wasn't different, I increased the standing duration for that object.

Problem I encountered:

The system which tracs the objects (almost) never delivers the same coordinates even if the object didn't physically move.

x:123 -> x:120 -> x:124 -> x:123 -> ...

Should I just round to centimeters or decimenters or are there "standard" GIS-algorithms to solve this?

Answer 1

I think dwell time and trajectory are more appropriate words for this. See "Estimating the most likely space–time paths, dwell times and path uncertainties from vehicle trajectory data: A time geographic method".

-- Tang J, Song Y, Miller HJ, Zhou X (2015)