rsaga.insolation: Incoming Solar Radiation (Insolation)

Description Usage Arguments Details Value Note Author(s) See Also

Description

This function calculates the amount of incoming solar radiation (insolation) depending on slope, aspect, and atmospheric properties. Module not available in SAGA GIS 2.0.6 and 2.0.7.

Usage

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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/cm2/min (=1360.7 kWh/m2; the more commonly used solar constant of 1367 kWh/m2 corresponds to 8.202 J/cm2/min)

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 Insolation (code: 3) from SAGA library ta_lighting. It is available in SAGA GIS 2.0.4 and 2.0.5 but not 2.0.6 and 2.0.7; see rsaga.pisr().

Author(s)

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

See Also

rsaga.solar.radiation(), rsaga.pisr(), rsaga.hillshade()


RSAGA documentation built on May 2, 2019, 11:01 a.m.