gps-track-filter
Fixes typical GPS data errors.
Quick start
Tuple<double, double, DateTimeOffset>[] rawGpsTrack =
{
Tuple.Create(55.6519383333333, 37.490125, new DateTimeOffset(2018, 12, 4, 13, 16, 19, 789, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6515131, 37.4893632, new DateTimeOffset(2018, 12, 4, 13, 16, 23, 789, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6519383333333, 37.490125, new DateTimeOffset(2018, 12, 4, 13, 16, 27, 789, TimeSpan.FromMinutes(0))),
Tuple.Create(55.65135, 37.4892033, new DateTimeOffset(2018, 12, 4, 13, 16, 43, 789, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6519383333333, 37.490125, new DateTimeOffset(2018, 12, 4, 13, 16, 47, 789, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6513234, 37.4891682, new DateTimeOffset(2018, 12, 4, 13, 17, 3, 790, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6519383333333, 37.490125, new DateTimeOffset(2018, 12, 4, 13, 17, 7, 790, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6518866666667, 37.4900783333333, new DateTimeOffset(2018, 12, 4, 13, 17, 23, 790, TimeSpan.FromMinutes(0))),
Tuple.Create(55.65179, 37.4899816666667, new DateTimeOffset(2018, 12, 4, 13, 17, 27, 790, TimeSpan.FromMinutes(0))),
Tuple.Create(55.651485, 37.4896166666667, new DateTimeOffset(2018, 12, 4, 13, 17, 35, 790, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6514033333333, 37.4895116666667, new DateTimeOffset(2018, 12, 4, 13, 17, 39, 791, TimeSpan.FromMinutes(0))),
Tuple.Create(55.651, 37.4899566666667, new DateTimeOffset(2018, 12, 4, 13, 17, 59, 791, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6509624, 37.4892313, new DateTimeOffset(2018, 12, 4, 13, 18, 3, 791, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6505566666667, 37.489675, new DateTimeOffset(2018, 12, 4, 13, 18, 19, 792, TimeSpan.FromMinutes(0))),
Tuple.Create(55.65011, 37.489775, new DateTimeOffset(2018, 12, 4, 13, 18, 39, 793, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6505939, 37.488777, new DateTimeOffset(2018, 12, 4, 13, 18, 43, 793, TimeSpan.FromMinutes(0))),
Tuple.Create(55.649861, 37.4901316, new DateTimeOffset(2018, 12, 4, 13, 19, 3, 793, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6507395, 37.4888707, new DateTimeOffset(2018, 12, 4, 13, 19, 43, 794, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6499716666667, 37.489845, new DateTimeOffset(2018, 12, 4, 13, 19, 47, 794, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6505815, 37.4891906, new DateTimeOffset(2018, 12, 4, 13, 20, 3, 795, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6506916666667, 37.48999, new DateTimeOffset(2018, 12, 4, 13, 20, 11, 795, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6511295, 37.4892963, new DateTimeOffset(2018, 12, 4, 13, 20, 23, 796, TimeSpan.FromMinutes(0))),
Tuple.Create(55.651045, 37.489525, new DateTimeOffset(2018, 12, 4, 13, 20, 27, 796, TimeSpan.FromMinutes(0))),
Tuple.Create(55.65148, 37.4898816666667, new DateTimeOffset(2018, 12, 4, 13, 20, 39, 796, TimeSpan.FromMinutes(0))),
Tuple.Create(55.651895, 37.4902716666667, new DateTimeOffset(2018, 12, 4, 13, 20, 43, 797, TimeSpan.FromMinutes(0))),
Tuple.Create(55.6527777, 37.4899073, new DateTimeOffset(2018, 12, 4, 13, 20, 47, 797, TimeSpan.FromMinutes(0)))
};
var filter = new GpsTrackFilter();
var gpsTrack = filter.Filter(rawGpsTrack);Algorithms
GpsTrackFilter implements follow algorithms:
- Zero/Negative timespan removing.
- Outline speed points removing.
- Zero speed drift smoothing.
- Simplified Kalman filtering.
Parameters
var filter = new GpsTrackFilter();
filter.ZeroSpeedDrift = 8.3;
ZeroSpeedDrift defines minimal speed to zero/negative drift filter. Default value is 7.99 kmh.
filter.OutlineSpeed = 130.0;
OutlineSpeed defines maximal speed to outline speed filter. Default value is 110.0 kmh.
filter.ModelPrecision = 4.14;
filter.SensorPrecision = 0.53;
ModelPrecision and SensorPrecison define standard deviations of physical model and GPS sensor in Kalman filter. Default values are 2.13 and 0.77.
Example
Raw track
Filterd track
