Working with spatio-temporal lat-lon fields

In this example, we demonstrate how to generate a spatio-temporal random field on geographical coordinates.

First we setup a model, with latlon=True and temporal=True, to get the associated spatio-temporal Yadrenko model.

In addition, we will use a kilometer scale provided by KM_SCALE as geo_scale to have a meaningful length scale in km. By default the length scale would be given in radians (RADIAN_SCALE). A third option is a length scale in degrees (DEGREE_SCALE).

To generate the field, we simply pass (lat, lon, time) as the position tuple to the SRF class.

We will set a spatial length-scale of 1000 and a time length-scale of 100 days.

import numpy as np

import gstools as gs

model = gs.Matern(
    latlon=True,
    temporal=True,
    var=1,
    len_scale=[1000, 100],
    geo_scale=gs.KM_SCALE,
)

lat = lon = np.linspace(-80, 81, 50)
time = np.linspace(0, 777, 50)
srf = gs.SRF(model, seed=1234)
field = srf.structured((lat, lon, time))
srf.plot()