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README.Rmd
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README.Rmd
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---
output: github_document
---
[](https://github.com/jhollist/elevatr/actions)
[](https://www.r-pkg.org/pkg/elevatr)
[](https://www.r-pkg.org/pkg/elevatr)
[](https://app.codecov.io/gh/jhollist/elevatr?branch=main)
[](https://zenodo.org/badge/latestdoi/65325400)
# Key information about version 0.99.0 and upcoming versions of `elevatr`
Several major changes have been made to `elevatr` in response to the retirement of legacy spatial packages (see
<https://r-spatial.org/r/2023/05/15/evolution4.html> for details). Version 0.99.0 has switched to using `sf` and `terra` for all data handling; however, in this version a `raster RasterLayer` is still returned from `get_elev_raster()`. Additional changes are planned for version 1+, most notably the return for `get_elev_raster()` will be a `terra SpatRaster`. Please plan accordingly for your analyses and/or packages account for this change.
# elevatr
An R package for accessing elevation data from various sources
The `elevatr` package currently provides access to elevation data from AWS Open Data [Terrain Tiles](https://registry.opendata.aws/terrain-tiles/) and the Open Topography [Global datasets API](https://opentopography.org/developers#API) for raster digital elevation models. For point elevation data,the [USGS Elevation Point Query Service](https://apps.nationalmap.gov/epqs/)) may be used or the point elevations may be derived from the AWS Tiles. Additional elevation data sources may be added as they come available.
Currently this package includes just two primary functions to access elevation web services:
- `get_elev_point()`: Get point elevations using the USGS Elevation Point Query Service (for the US Only) or using the AWS Terrain Tiles (global). This will accept a data frame of x (long) and y (lat), a Simple Features object, or `terra` SpatRaster as input. A Simple Features object is returned of the point locations and elevations.
- `get_elev_raster()`: Get elevation data as a raster (e.g. a Digital Elevation Model) from the AWS Open Data Terrain Tiles or Open Topography Global datasets. Other sources may be added later. This will accept a data frame of of x (long) and y (lat) or any `sf` or `terra` SpatRaster object as input and will return a terra `SpatRaster` object of the elevation. The extent of the SpatRaster is the full tiles that cover the bounding box of the input spatial data, but may be clipped to the shape or bounding box of the input locations.
## Installation
Version 0.99.0 of this package is currently available from CRAN and may be installed by:
```{r eval=F}
install.packages("elevatr")
```
The development version (this repo) may installed with `devtools`:
```{r, eval=F}
library(devtools)
install_github("jhollist/elevatr")
```
## Contributions and Use Cases
As `elevatr` is getting more widely used, there have been some great contributions, use cases, and additional packages that have come from the user community. If you have one you'd like to share, let me know and I will gladly add it. Here are some of the ones that I have seen. Thank you all!
- [Michaela Mulhearn's `rayshader` and `elevatr` cheatsheet](https://github.com/jhollist/elevatr/blob/main/contributions/mulhearn_rayshader_elevatr_cheatsheet.pdf)
- researchremora on twitter has created some amazing elevation maps
- [Hugh Graham's `rayvista` package uses `rayshader`, `maptiles`, and `elevatr` to create some cool visualizations](https://github.com/h-a-graham/rayvista)
- [Spencer Schien has built some fantastic shaded relief visulaizations and provided the code to recreate them](https://github.com/Pecners/rayshader_portraits)
## Attribution
Mapzen terrain tiles (which supply the AWS source) contain 3DEP, SRTM, and GMTED2010 content courtesy of the U.S. Geological Survey and ETOPO1 content courtesy of U.S. National Oceanic and Atmospheric Administration. The Open Topography API provide access to the SRTM and the ALOS World 3D datasets. See <https://opentopography.org/> for details.
## Repositories
The source code for this repository is maintained at https://github.com/jhollist/elevatr which is also mirrored at https://github.com/usepa/elevatr
## EPA Disclaimer
The United States Environmental Protection Agency (EPA) GitHub project code is provided on an "as is" basis and the user assumes responsibility for its use. EPA has relinquished control of the information and no longer has responsibility to protect the integrity , confidentiality, or availability of the information. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply their endorsement, recommendation or favoring by EPA. The EPA seal and logo shall not be used in any manner to imply endorsement of any commercial product or activity by EPA or the United States Government.