rsaga.insolation {RSAGA}R Documentation

Incoming Solar Radiation (Insolation)

Description

This function calculates the amount of incoming solar radiation (insolation) depending on slope, aspect, and atmospheric properties.

Usage

rsaga.insolation(in.dem, in.vapour, in.latitude, in.longitude, 
    out.direct, out.diffuse, out.total, horizontal = FALSE, 
    solconst = 8.164, atmosphere = 12000, water.vapour.pressure = 10, 
    type = c("moment", "day", "range.of.days", "same.moment.range.of.days"), 
    time.step = 1, day.step = 5, days, moment, latitude, bending = FALSE, 
    radius = 6366737.96, lat.offset = "user", lat.ref.user = 0, 
    lon.offset = "center", lon.ref.user = 0, ...)

Arguments

in.dem Name of input digital elevation model (DEM) grid in SAGA grid format (default extension: .sgrd)
in.vapour Optional input: SAGA grid file giving the water vapour pressure in mbar
in.latitude Optional input: SAGA grid file giving for each pixel the latitude in degree
in.longitude Optional input: SAGA grid file giving for each pixel the longitude in degree
out.direct Optional output grid file for direct insolation
out.diffuse Optional output grid file for diffuse insolation
out.total Optional output grid file for total insolation, i.e. the sum of direct and diffuse insolation
horizontal logical; project radiation onto a horizontal surface? (default: FALSE, i.e. use the actual inclined surface as a reference area)
solconst solar constant in Joule; default: 8.164 J
atmosphere height of atmosphere in m; default: 12000m
water.vapour.pressure if no water vapour grid is given, this argument specifies a constant water vapour pressure that is uniform in space; in mbar, default 10 mbar
type type of time period: "moment" (equivalent: 0) for a single instant, "day" (or 1) for a single day, "range.of.days" (or 2), or "same.moment.range.of.days" (or 3) for the same moment in a range of days; default: "moment"
time.step time resolution in hours for discretization within a day
day.step time resolution in days for a range of days
days numeric vector of length 2, specifying the first and last day of a range of days (for types 2 and 3)
moment if type="moment" or "same.moment.range.of.days", moment specifies the time of the day (hour between 0 and 24) for which the insolation is to be calculated
latitude if no in.latitude grid is given, this will specify a fixed geographical latitude for the entire grid
bending should planetary bending be modeled? (default: FALSE)
radius planetary radius
lat.offset latitude relates to grids "bottom" (equivalent code: 0), "center" (1), "top" (2), or "user"-defined reference (default: "user"); in the latter case, lat.ref.user defines the reference
lat.ref.user if in.latitude is missing and lat.offset="user", then this numeric value defines the latitudinal reference (details??)
lon.offset local time refers to grid's "left" edge (code 0), "center" (1), "right" edge (2), or a "user"-defined reference.
lon.ref.user if in.longitude is missing and lon.offset="user", then this numeric value defines the reference of the local time (details??)
... optional arguments to be passed to rsaga.geoprocessor, including the env RSAGA geoprocessing environment

Details

Calculation of incoming solar radiation (insolation). Based on the SADO (System for the Analysis of Discrete Surfaces) routines developed by Boehner & Trachinow.

Value

The type of object returned depends on the intern argument passed to the rsaga.geoprocessor. For intern=FALSE it is a numerical error code (0: success), or otherwise (default) a character vector with the module's console output.

Note

This function uses module 3 from SAGA library ta_lighting.

Author(s)

Alexander Brenning (R interface), Olaf Conrad (SAGA module)

See Also

rsaga.solar.radiation, rsaga.hillshade


[Package RSAGA version 0.9-5 Index]