...I wasn't sure if this question was best suited to GIS, SO or Math, so after reading GIS Topics I decided to ask here, but I'll relocate if necessary... :-)

I'm working on automating various analyses of movement and activities based on various sizable (50K→500K) sets of datetime/latitude/longitude data.

I'd like to determine "Average Moving Speed".

  1. Parts of the recordset will have little or no movement
  2. Other parts will have movement of varying speeds (ie., walking or driving), and,
  3. A few records will (frustratingly) contain what I assume are GPS errors: Sudden "hops" to an unrealistic distance, returning to the previous location in the following record.

Is there a standard method of determining Average Moving Speed?

  • Perhaps a minimum distance that is considered "actual movement" as opposed to GPS resolution or reporting issues, or

  • Maybe there is a standard formula or algorithm that I haven't found yet.

I'm comfortable with coding and I've brainstormed and experimented with a few methods but each seems to have it's own issues.

Possible methods:

  • Skipping every n records (Surely the worst option.)

  • Skipping records between "whole minutes" or "whole 3 minutes" etc (Some legitimate movement would be missed.)

  • An interpretation of Rolling Average.

I figure that once I can extrapolate Average Moving Speed, I will be able to deduce Activity Type -- ie., whether the movement was most likely walking, driving, flying, idle, etc... but I'd be interested to hear thoughts about that as well.

From what I understand Rolling Average would be, instead of looking at the current record, take an average of n records before and n records after the current record.

If that's the case, there could still be various interpretations:

  • Take separate averages of the n + n + 1 Lon's & Lat's and use those numbers to calculate movement

  • Averages of each n + n + 1 records elapsed time, divided by Averages of each n + n + 1 records' distance traveled

  • I will try out any ideas you may have and report my findings back here.

An example of the data (with distance [meters] and time [seconds] added, at individual-record level): (and this link to a downloadable 200-record CSV sample)

example data

Some places I've looked for insight (without success, unless I missed something):

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