get_landsat: Get Landsat SR Products

In joshualerickson/exploreRGEE: Explores Google Earth Engine

Get Landsat SR Products

Description

This function gets 30-m USGS Landsat 8, 7 , 5 and 4 (Surface Reflectance Tier 1 (SR)) satellite images from various bands. The image processing for time series can either use methods by Roy et al. (2016) (e.g. harmonization) so that all three Landsat missions will be scaled for a harmonized time series analysis ('harm_ts') or you can just get time series without harmonizing ('ts'). All the methods will use Zhu et al. (2015) masking function and filter image properties by cloud cover less than 50% and Geometric RMSE Model less than 10.

Usage

get_landsat(
  aoi,
  method = "ld8",
  param = NULL,
  stat = "median",
  cloud_mask = TRUE,
  startDate = "1984-01-01",
  endDate = "2020-10-30",
  mask = FALSE,
  m.low = NULL,
  m.high = NULL,
  c.low = 1,
  c.high = 12
)

Arguments

aoi	A sf object indicating the extent of the geom.
method	A character indicating what method to use, e.g. 'ld8', 'ld7', 'ld5', 'ld4', 'ts', 'harm_ts'.
param	A character indicating what band to visualize, e.g. 'Blue' or c('Green', 'Red', 'NIR') or NULL returns all bands.
stat	A character indicating what to reduce the imageCollection by, e.g. 'median' (default), 'mean', 'max', 'min', 'sum', 'sd', 'first'.
cloud_mask	logical whether to mask out certain cloud artifacts. TRUE (default).
startDate	character format date, e.g. "1999-10-23"
endDate	character format date, e.g. "1999-10-23"
mask	logical whether to mask out certain ranges
m.low	numeric low value for mask, e.g. greater than 'm.low'
m.high	numeric high value for mask, e.g. less than 'm.high'
c.low	numeric lower month value for calendar range
c.high	numeric higher month value for calendar range

Details

The methods currently available (more to come):

• harm_ts: Harmonizing Landsat Missions; 1984-01-01 - 2021-01-22.

• ts: Combining Landsat Missions; 1984-01-01 - 2021-01-22.

• ld8: LANDSAT/LC08/C01/T1_SR; 2013-04-11 - 2021-01-22.

• ld7: LANDSAT/LC07/C01/T1_SR; 1999-01-01 - 2021-01-21.

• ld5: LANDSAT/LC05/C01/T1_SR; 1984-01-01 - 2012-05-05.

• ld4: LANDSAT/LC04/C01/T1_SR; 1982-08-22 - 1993-12-14.

The param (bands) currently available (more to come):

• Blue, Green, Red, NIR,SWIR1, SWIR2, NDVI, NDWI, NBR

Value

A list of Earth Engine Objects and arguments.

Note

If you want to use this with #eemont functions then make sure cloud_mask is set to FALSE. Also, 'harm_ts' and 'ts' can take a long time to process in other function viz, rr and band so be aware!

Examples

## Not run: 
# Load Libraries

library(rgee)
ee_Initialize()
library(exploreRGEE)

# Bring in data
huc <- exploreRGEE::huc

ld8 <- get_landsat(huc, method = 'ld8', startDate = '2014-01-01',
                  endDate = '2018-12-31', c.low = 6, c.high = 11)



## End(Not run)

joshualerickson/exploreRGEE documentation built on May 9, 2022, 10:33 p.m.