gshhsMask: A land mask based on the GSHHS data set

In SWotherspoon/Marseille: Telemetry Track Filtering and Simulation

Description

Generate a land mask function based on the Global Self-consistent, Hierarchical, High-resolution Geography Database. The mask is provided at two (approximate) spatial resolutions: 0.1 degree and 0.05 degrees. The latter requires significantly more memory.

Usage

gshhsMask(res = c("0.1", "0.05"), land = FALSE, latmin = -90,
  latmax = 90)

Arguments

res	the spatial resolution of the mask, in degrees
land	the logical value returned for land
latmin	the minimum allowable latitude
latmax	the maximum allowable latitude

Details

Returns a function of three arguments

'tm'

time

'lon'

longitude

'lat'

latitude

This mask is time independent and the tm argument to the mask is ignored.

Value

function of three arguments (tm,lon,lat) that returns a logical indicating whether (lon,lat) is at sea or on land and inside the allowable latitude range

References

Wessel, P., and W. H. F. Smith, A Global Self-consistent, Hierarchical, High-resolution Shoreline Database, J. Geophys. Res., 101, #B4, pp. 8741-8743, 1996. https://www.ngdc.noaa.gov/mgg/shorelines/gshhs.html

See Also

dcrwSimulate

Examples

mask  <- gshhsMask() ## initialize land mask function
mask(0,100,-65) ## test point - time lon,lat

SWotherspoon/Marseille documentation built on May 9, 2019, 12:05 p.m.