This resource is published by Jarvis et al. (2008) "Hole-filled seamless SRTM data V4". The layer represents the 30m global terrestrial digital elevation model from the NASA Shuttle Radar Topographic Mission (SRTM), available for download as 5 degree x 5 degree tiles. It is encoded as meter, representing the elevation at the particular grid cell.
Details
Important Note:
As of January 2023, the SSL certificate of the website where this resource is downloaded from has expired. We include a check and inform users that this resource might not be downloaded without unsetting SSL certification checks on their own risk. The maintainers of the website have been contacted and asked to renew the certificate. Until then, users can decide to disable the SSL certification checks for their preferred downloading method. Using wget as an example, the following options can be set to disable the SSL checks at your own risk:
httr::set_config(httr::config(ssl_verifypeer = 0L))
options(download.file.method="wget", download.file.extra="--no-check-certificate")
This assumes that your are not using the aria2 downloader.