README.md

In jpshanno/nohrsc: Access NOAA National Operational Hydrologic Remote Sensing Center's Snow Analysis Data Archive

nohrsc

nohrsc is designed to make it easy to access the NOHRSC data archive. It takes common name arguments and dates to construct the proper URLs and access the correctly formatted file names. Multiple days and products can be downloaded and extracted in a single call. The extracted rasters will be converted to *.bil format and an appropriate *.hdr and *.prj will be created for each raster.

Installation

If you are using Windows you should install nohrsc by downloading the binary version (see below) of the package. Otherwise you can build nohrsc from these source files.

Windows Installation

url = "https://drive.google.com/file/d/1blFGzzeLpTuuKM_Bfq812CIGQ9m88VH2/view?usp=sharing"
fn = tempfile(fileext=".zip")
download.file(destfile = fn, url = url)
install.packages(fn, repos = NULL)

remotes Linux Installation

remotes::install_github("jpshanno/nohrsc")

or without remotes by Linux Installation without remotes package

nohrsc_source <- file.path(tempdir(), "nohrsc-master.zip")
download.file("https://github.com/jpshanno/nohrsc/archive/master.zip",
              nohrsc_source)
unzip(nohrsc_source,
        exdir = dirname(nohrsc_source))
install.packages(sub(".zip$", "", nohrsc_source),
                 repos = NULL,
                 type = "source")

Development Timeline

Minimum Viable Product

• [x] Download data (use *apply to make >1 easy)
• [ ] Automatic data handling if path not specified (via rappdirs)
• [ ] Query/Load downloaded data
• [ ] Add citations to NOHRSC data & documentation
• [ ] Unit tests
• [ ] Use assertthat to check archive/raster filenames etc

First Improvement

• [ ] Improve queries
• [ ] Delete data

Second Improvement

• [ ] Allow clipping before storage to save disk space
• [ ] Change NA values being recorded as large positive integers

Example

Download data over three days and extract SWE and melt data:

library(nohrsc)
rasters <- 
  nsa_get_snodas(product = c("snow water equivalent", "snow melt"),
                 start.date = "2015-04-01",
                 end.date = "2015-04-03",
                 path = "snodas")

jpshanno/nohrsc documentation built on Feb. 20, 2023, 7:33 p.m.