lmvt: Calculate UTC and local time from Local Solar Time

In MLezamaValdes/LocST:

Description

calculate UTC and local time from Local Solar Time, as provided e.g. in MODIS viewtime rasters

Usage

lmvt(fnam, viewtime, ra = NULL, aoiproj = NULL, ltz = NULL)

Arguments

ra	optional: extent of the area of interest, projected in the local projection to be provided in aoiproj
aoiproj	optional, but required if ra is being used: local projection of the area of interest
ltz	local time zone, e.g. "Pacific/Auckland" or "EST" to be found in R function OlsonNames()
LocST	Local solar time vector in mm:hh format or as a viewtime raster in decimal format or decimal format only
utc	UTC day that was provided e.g. via filename or the corresponding UTC day (infered based on the local time zone the local solar time was reported for conversion to UTC time), format ='%Y-%m-%d' or as POSIXlt date
lon	required only if no raster is used for LocST, to provide as decimal point numeric

Value

data frame with lon (and lat in case of raster input), as well as decimal format local solar time ("LocST"), hour format local solar time "LocST_h", UTC date calculated from LocST "utc_from_LocST", the original UTC input provided ("orgUTC") and a time difference between provided and calculated UTC times in case a POSIXlt format UTC date with time input was provided (available e.g. in case of MODIS L2/swath data)

Author(s)

Maite Lezama Valdes

Examples

library(raster)
vt_raster <-  raster(system.file("extdata", "vtr_s.tif", package="LocST"))
aoi_ext <- extent(-120775.7, -37096.71, 6686761, 6782394)
aoiproj <- "+proj=utm +zone=54 +south +ellps=WGS84 +datum=WGS84 +units=m +no_defs"

lmvt(fnam="MOD11_L2.A2018019.1350.006.2018020082352.hdf",
     viewtime = vt_raster, ra=NULL, aoiproj=NULL, ltz="Australia/ACT")

# with Swath data + optionally: cut to area of interest and calculate also local timezone
lmvt(fnam="MOD11_L2.A2018019.1350.006.2018020082352.hdf",
     viewtime = vt_raster, ra=aoi_ext, aoiproj=aoiproj, ltz="Australia/ACT")

lmvt(fnam="MOD11A1.A2018019.h29v12.006.2018020085050.hdf",
     viewtime = vt_raster, ra=NULL, aoiproj=NULL, ltz="Australia/ACT")

MLezamaValdes/LocST documentation built on June 6, 2019, 7:40 p.m.