Search satellite images

Search satellite images concerning a particular location, data product, and date interval. The function returns a records object if the region is a sf. If an rtoi is used, the function returns nothing and the records are added to the rtoi.

Usage

rsat_search(region, product, ...)

# S4 method for class 'rtoi,character'
rsat_search(region, product, verbose = FALSE, ...)

# S4 method for class 'sf,character'
rsat_search(region, product, verbose = FALSE, ...)

Arguments

region

a Spatial*, Raster*, sf or rtoi class objects defining the region of interest.

product

a character vector of product names.

...

additional arguments for searching

verbose

logical argument. If TRUE, the function prints the running steps and warnings.

Value

nothing if x is an rtoi, records class if you search a region.

Details

MODIS images are found through the NASA Common Metadata Repository (CMR). The inventory of MODIS products can be found here. The catalog shows the product short names and detailed information. MODIS surface reflectance products are named `mod09ga' and `myd09ga' for Terra and Aqua satellites. By the time rsat is released, NASA carries out the maintenance of its website on Wednesdays, which may cause an error when connecting to their server.

We use ESA's powered API (`SciHub') to find Sentinel images. The catalog of Sentinel-2 and -3 products can be found here and here, respectively. Sentinel-2 and -3 surface reflectance product names are referred to as `S2MSI2A' and `SY_2_SYN___'.

Landsat images are accessed via the Machine-to-Machine API. Details about the Landsat products can be found here. The names of Landsat products are `LANDSAT_TM_C1', `LANDSAT_ETM_C1', and `LANDSAT_8_C1' for missions 4-5, 7, and 8.

Examples

if (FALSE) { # \dontrun{
library(rsat)
set_credentials("username", "password")

# search navarre images using sf
record.list <- rsat_search(
  region = ex.navarre,
  product = "mod09ga",
  dates = as.Date("2011-01-01") + seq(1, 10, 1)
)

# creating a new rtoi
rtoi.path <- tempdir()
navarre <- new_rtoi(
  "Navarre", # name of the region
  ex.navarre, # sf of the region
  rtoi.path
) # path for the rtoi

# see the number of records in navarre
print(navarre)

# search modis images using rtoi
rsat_search(
  region = navarre,
  product = "mod09ga",
  dates = as.Date("2011-01-01") + seq(1, 10, 1)
)

# see the number of records in navarre
print(navarre)

# search landsat images using rtoi
rsat_search(
  region = navarre,
  product = "LANDSAT_8_C1",
  dates = as.Date("2016-01-01") + seq(1, 30, 1)
)

# see the number of records in navarre
print(navarre)

# search sentinel-2 (level 1 and level 2) images using rtoi
rsat_search(
  region = navarre,
  product = c("S2MSI1C", "S2MSI2A"),
  dates = as.Date("2016-01-01") + seq(1, 30, 1)
)

# see the number of records in navarre
print(navarre)

# search sentinel-3 level-2 images using rtoi
rsat_search(
  region = navarre,
  product = "OL_2_LFR___",
  dates = as.Date("2019-01-01") + seq(1, 2, 1)
)

# search sentinel-1 level-2 images using rtoi
rsat_search(
  region = navarre,
  product = "GRD",
  dates = as.Date("2019-01-01") + seq(1, 2, 1)
)

# search Landsat-5 images using rtoi
rsat_search(
  region = navarre,
  product = "LANDSAT_TM_C1",
  dates = as.Date("1988-08-01") + seq(1, 35)
)

print(navarre)

# get all records from rtoi
navarre.records <- records(navarre)

print(navarre.records)
} # }