download: Download of NDVI Products

In environmentalinformatics-marburg/ESD:

Description

This function serves as a wrapper around the underlying product-related download functions. Currently supported datasets originate from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra and Aqua satellite platforms and the Advanced Very High Resolution Radiometer (AVHRR) Global Inventory Modeling and Mapping studies (GIMMS).

Usage

download(type = c("MODIS", "GIMMS"), ...)

Arguments

type	character. Currently available options are "MODIS" (default) and "GIMMS".
...	Additional arguments passed to the underlying download functions for MODIS (runGdal; see 'Details') and GIMMS data (downloadGimms).

Details

Note that when working with the MODIS M*D13 product series, the optional 'SDSstring' argument passed to runGdal must at least include the following four SDS:

• 'NDVI' (or 'EVI'), #1 (or #2)

• 'VI_Quality', #3

• 'pixel_reliability', #12

• 'composite_day_of_the_year', #11

Accordingly, the minimum requirement for 'SDSstring' is "101000000011" ("011000000011") for the NDVI (EVI).

Value

If type = "GIMMS", a character vector of local filenames. Else if type = "MODIS", a list of product and date-specific output files in character format, see runGdal.

Author(s)

Florian Detsch

References

LP DAAC (2016) MOD13Q1: MODIS/Terra Vegetation Indices 16-Day L3 Global 250m Grid SIN V006. Available online: https://lpdaac.usgs.gov/dataset_discovery/modis/modis_products_table/mod13q1_v006.

See Also

runGdal, downloadGimms.

Examples

## Not run: 
## Reference extent (Schwaebische Alb)
ext <- readRDS(system.file("extdata/alb.rds", package = "ESD"))

## MODIS download
mds <- download("MODIS", product = "M*D13A1", collection = "006", 
                extent = ext, begin = "2015001", end = "2015031")
mds                 

## GIMMS download
gms <- download("GIMMS", x = as.Date("2015-01-01"), y = as.Date("2015-01-31"),
                dsn = paste0(getOption("MODIS_outDirPath"), "NDVI3g.v1_alb"))
gms                 

## End(Not run)

environmentalinformatics-marburg/ESD documentation built on May 16, 2019, 7:49 a.m.