Auto-detect breaks/pauses

[opatut]

Sometimes I leave my device recording while I go into a store or similar.

It would be nice if we had some way of detecting this, because the GPS jitters around in the place I stopped (due to inaccuracy), and that accumulates a lot of incorrect mileage on the track that I don't like in the statistics.

Probably some moving window distance traveled/time formula could detect this, find the center of the points inside that timeframe, and clip everything from the entry to the exit of a radius around that point. This can become incredibly smart, but somethin stupid might do the trick for starters.

[FlorusCiphersmith]

Does anyone (@opatut) have a sample file which is affected by the GPS noise during a pause?

While testing a first implementation, I noticed that the files I used seem not to be affected. Indeed, there seems to be already a filter in action (on the GPS device?) which does the job well at the first glance - see the example below.

Or do we need additional filtering?

Date	Time	Millis	Comment	Latitude	Longitude	Altitude	Course	Speed	HDOP	Satellites
01.02.2021	07:40:55	5424030		48,678123	8,983156	452,5	292,01	10,59	1,09	7
01.02.2021	07:40:56	5425039		48,678143	8,983127	452,8	309,68	9,76	1,09	7
01.02.2021	07:40:57	5426045		48,678164	8,983111	452,8	326,37	9,41	1,09	7
01.02.2021	07:40:58	5427033		48,678187	8,983074	452,7	320,46	10,56	1,09	7
01.02.2021	07:40:59	5428041		48,678203	8,983031	452,7	308,73	11,13	1,09	7
01.02.2021	07:41:00	5429028		48,678203	8,983009	452,8	300,71	8,57	1,09	7
01.02.2021	07:41:01	5430038		48,6782	8,983009	452,6	300,71	2,85	1,09	7
01.02.2021	07:41:02	5431025		48,67821	8,982994	452,9	300,71	1,24	1,09	7
01.02.2021	07:41:03	5432087		48,678233	8,982957	454,7	300,71	0,3	1,09	7
01.02.2021	07:41:04	5433042		48,678241	8,98295	454,7	300,71	0,28	1,09	7
01.02.2021	07:41:05	5434040		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:06	5435024		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:07	5436030		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:08	5437036		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:09	5438028		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:10	5439038		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:11	5440024		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:12	5441032		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:13	5442039		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:14	5443024		48,678241	8,98295	454,7	300,71	0	1,09	7
01.02.2021	07:41:15	5444011		48,678241	8,98295	454,7	300,71	0	1,09	7

[amandel]

Since a while we tell the GPS Module that it should use the pedestrian profile for plausibility checks and filtering of movements. Likely this is what you observe.

From the spec: Pedestrian Applications with low acceleration and speed, e.g. how a pedestrian would move. Low acceleration assumed. MAX Altitude [m]: 9000, MAX Velocity [m/s]: 30, MAX Vertical Velocity [m/s]: 20, Sanity check type: Altitude and Velocity, Max Position Deviation: Small