solarHourAngle: Compute solar hour angle

In environmentalinformatics-marburg/satelliteTools: What the package does (short line)

Description

Compute the solar hour angle which is defined as the time difference from noon times 15 degrees per hour (i.e., negative during the morning and positive during the afternoon).

Usage

## S4 method for signature 'POSIXt'
solarHourAngle(x, unit = c("radians", "degrees"))

## S4 method for signature 'character'
solarHourAngle(x, unit = c("radians", "degrees"), ...)

## S4 method for signature 'Raster'
solarHourAngle(x, origin = strptime("1993-01-01",
  "%Y-%m-%d"), unit = c("radians", "degrees"), ...)

Arguments

x	A date-time object of class POSIX*, or a character object that can be coerced by strptime, or a Raster* object holding such information.
unit	character, determines whether to return the hour angle in radians (default) or degrees.
...	If x is a character object, formatting arguments passed on to strptime, or if x is a Raster* object, formatting arguments related with the specified origin.
origin	A POSIX* or character object that defines the starting point of x, defaults to the origin of MOD05_L2 'Scan_Start_Time' (midnight of 1 January 1993, see https://modis-atmosphere.gsfc.nasa.gov/MOD05_L2/format.html).

Value

numeric solar hour angle(s), or if x is a Raster* object, a Raster* object with pixel-wise solar hour angles.

Examples

## current solar hour angle
solarHourAngle(Sys.time(), unit = "degrees")

environmentalinformatics-marburg/satelliteTools documentation built on May 16, 2019, 8:16 a.m.