get_ned

A Raster* or Spatial* object to serve 
as a template for cropping, and perhaps resolution.

template

A character string naming the study area.

label

A character string representing the desired resolution of the NED. "1"
indicates the 1 arc-second NED (the default), while "13" indicates the 1/3 arc-second dataset.

A character string indicating where raw downloaded files should be put.
The directory will be created if missing. Defaults to "./RAW/NED/".

raw.dir

A character string indicating where the extracted and cropped DEM should be put.
The directory will be created if missing. Defaults to "./EXTRACTIONS/NED/".

extraction.dir

If an extraction for this template and label already exists, should a new one be created?

force.redo


<code>get_ned</code> returns a <code>RasterLayer</code> of elevation data cropped to a given
template study area.


Functions to automate downloading geospatial data available from
several federated data sources (mainly sources maintained by the US Federal
government). Currently, the package allows for retrieval of five datasets:
The National Elevation Dataset digital elevation models (1 and 1/3 arc-second;
USGS); The National Hydrography Dataset (USGS); The Soil Survey Geographic
(SSURGO) database from the National Cooperative Soil Survey (NCSS), which is
led by the Natural Resources Conservation Service (NRCS) under the USDA; the
Global Historical Climatology Network (GHCN), coordinated by National Climatic
Data Center at NOAA; and the International Tree Ring Data Bank. Additional
data sources are in the works, including global DEM resources (ETOPO1, ETOPO5,
ETOPO30, SRTM), global soils (HWSD), MODIS satellite data products, the National
Atlas (US), Natural Earth, PRISM, and WorldClim.

get_ned: Download and crop the 1 (~30 meter) or 1/3 (~10 meter) arc-second National Elevation Dataset.

Description

Usage

Arguments

Value