The gbon module#

GBON resolution#

This gbon module encodes the applicable GBON horizontal resolutions for different station types within the function:

get_resolution(station_type: str, over: str = 'land', high_density: bool = False) → int[source]

Returns the GBON horizontal resolution for a given station type.

Parameters:

  • station_type (str) – one of ['surface', 'upper-air'].

  • over (str, optional) – one of ['land', 'sea']. Defaults to 'land'.

  • high_density (bool, optional) – if True, will return the GBON high density value. Defaults to False.

Returns:

the GBON horizontal resolution in km

Return type:

int

Example

To get the GBON horizontal resolution for a surface station over land, with standard density:

from wmoutils import gbon

res_in_km = gbon.get_resolution(station_type='surface', over='land', high_density=False)

GBON radius of influence#

The true raison d’être of the gbon module is to ease the derivation of the radius of influence of GBON stations, via the function:

get_influence_radius(station_type: str, over: str = 'land', high_density: bool = False) → float[source]

Returns the so-called radius of influence of a GBON station given its type.

The radius of influence is computed as R = (GBON horizontal resolution)/2 x sqrt(2), and represent the radius of the circle that ought to be drawn around each GBON stations when assembling network maps.

Parameters:

  • station_type (str) – one of ['surface', 'upper-air'].

  • over (str, optional) – one of ['land', 'sea']. Defaults to 'land'.

  • high_density (bool, optional) – if True, will return the GBON high density value. Defaults to False.

Returns:

the radius of influence in km.

Return type:

float

Example

To get the the GBON radius of influence for a surface station over land, with standard density:

from wmoutils import gbon

radius_in_km = gbon.get_influence_radius(station_type='surface', over='land',
                                         high_density=False)

Notes

The concept of radius of influence for GBON stations was first introduced in Appendix A of the SOFF National Contribution Plan for the Democratic Republic of Congo, see Vogt et al. (2024). What follows is a summary of the relevant section of this document, to which we refer the interested reader for more details.

The radius of influence R_inf of a GBON station corresponds to the maximum horizontal distance between the station and any geographical location situated closer to this station than any other GBON station.

When performing a so-called baseline GBON gap analysis, WMO adopts the premise that GBON stations are being distributed on a regular, orthogonal, two-dimensional grid, with a horizontal/vertical distance between stations equal to the relevant GBON horizontal resolution.

Under this specific premise, all stations thus have the same baseline radius of influence of:

R_inf = sqrt(2)/2 x (GBON horizontal resolution)

which represent the longest distance between any geographical point and its closest GBON station.