Grids

GeoGrids.jl offers a straightforward way to generate grids on a sphere, including Fibonacci and rectangular patterns. This builds on a long history of methods developed to evenly distribute points or create practical grid layouts on spherical surfaces, a challenge in fields like geospatial analysis and climate modeling. The module aims to provide a simple, flexible tool for working with these grids in a variety of applications.

Icosahedral Grid

The function icogrid returns a Vector of Point{🌐,<:LatLon{WGS84Latest}} elements, representing a global grid built with an icosahedral-based method.

grid = icogrid(sepAng=10)
plot = plot_geo_points(grid; title="Ico Grid")

At least one of N, the number of points to generate, or sepAng, the separation angle between points, must be provided.

The problem of how to evenly distribute points on a sphere has a very long history. Unfortunately, except for a small handful of cases, it still has not been exactly solved. Therefore, in nearly all situations, we can merely hope to find near-optimal solutions to this problem. Of these near-optimal solutions, the icosahedral grid is one approach that provides a more uniform distribution of points on a sphere compared to simple latitude-longitude grids. It starts with a regular icosahedron inscribed in a sphere and then subdivides its faces to create a finer mesh. This method of point distribution aims to provide a more uniform coverage of the Earth's surface, which can be particularly useful for global-scale simulations or analyses.

The function returns points in the WGS84 coordinate system, represented as latitude-longitude pairs.

Rectangular Grid

The function rectgrid generates a rectangular grid of points on the Earth's surface. It returns a Matrix of Point{🌐,<:LatLon{WGS84Latest}} elements, representing a global grid with the specified parameters. This rectangular grid can be useful for various geospatial applications, such as creating evenly spaced sampling points across the globe or defining a regular grid for data analysis and visualization.

grid = rectgrid(10)[:]
plot = plot_geo_points(grid; title="Rect Grid")

Vector Grid

The vecgrid function generates a vector of latitude points ranging from 0° (the equator) to 90° (the North Pole) at a fixed longitude of 0°. It returns a Vector of Point{🌐,<:LatLon{WGS84Latest}} elements, representing a grid of latitudes with the specified resolution.

This vector grid can be useful for various applications that require sampling or analysis along a meridian, such as studying latitudinal variations in climate data, or creating a basis for more complex grid structures.

grid = vecgrid(10)
plot = plot_geo_points(grid; title="Vector Grid")

The gridRes parameter must be provided, which is the resolution for the latitude grid spacing. This can be a real number (interpreted as degrees) or a ValidAngle.