Terrain Data Sources
Data available through automatic download
Global Terrain Data Sources
SRTM 1" 
Global 1" DSM between 60 degrees north and 60 degrees south. Pathloss 6 can automatically download and configure SRTM terrain data.
https://www2.jpl.nasa.gov/srtm/
This data is normally used as a clutter source, but can be used as terrain data.
ASTER 1" 
Pathloss 6 can automatically download and configure ASTER terrain data. Downloading 1" ASTER data requires a NASA Earthdata Login username and password. To obtain a NASA Earthdata Login account, please visit:
https://urs.earthdata.nasa.gov/users/new/
More information on ASTER data can be found at:
https://asterweb.jpl.nasa.gov/gdem.asp
CGLC100 - Copernicus Global Land Cover 100m 
Global Land Clutter data in 100m resolution. Pathloss 6 can automatically download and configure CGLC100 terrain data.
https://land.copernicus.eu/global/products/lc
GeoJSON Editor
Create buildings or other features in the GeoJSON format and use in Pathloss 6. This is useful for adding proposed structures or structures that may not exist in other data sources. See Vector Data for instruction on using GeoJSON data
3D Building Data
3D Building data for the world in GeoJSON format. See Vector Data for instruction on using GeoJSON data
North America - US, Canada and Mexico
In addition to the the Global sources, the following data is available for North America:
USGS NED 1" 
Bare earth terrain data for North America.
https://www.usgs.gov/publications/national-elevation-dataset
United States
In addition to the the Global and North America sources, the following data is available for the USA:
USGS 1/3" NED 
https://www.usgs.gov/publications/national-elevation-dataset
USGS NLCD 1" - National Land Clutter Data 
Description clutter data for the USA. This data is updated every 3 years.
https://www.usgs.gov/centers/eros/science/national-land-cover-database
USGS 1/9" NED
Very high resolution terrain data for parts of the US. This data is in the ERDAS IMG format and can be used directly with Pathloss 6.
This data can be downloaded from:
https://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Elevation/19/IMG/
USGS LIDAR Explorer
Very high resolution DSM data. This data can be used as Clutter 2 data source to provide very detailed clutter heights.
The data must be processed and output as a GeoTIFF file either on the USGS site or by using PDAL locally.
https://apps.nationalmap.gov/lidar-explorer/#/
Canada
In addition to the the Global and North America sources, the following data is available for Canada:
High Resolution Digital Elevation Model (HRDEM)
Very high resolution elevation and surface models for select Canadian cites. The data is UTM projected and uses the BIL Projected selection in the GIS setup window.
DTM - https://ftp.maps.canada.ca/pub/elevation/dem_mne/highresolution_hauteresolution/dtm_mnt
DSM - https://ftp.maps.canada.ca/pub/elevation/dem_mne/highresolution_hauteresolution/dsm_mns
Canadian Digital Elevation Model (CDEM)
http://ftp.geogratis.gc.ca/pub/nrcan_rncan/elevation/cdem_mnec/
Canadian Digital Surface Model (CDSM)
http://ftp.geogratis.gc.ca/pub/nrcan_rncan/elevation/cdsm_mnsc/
France
https://geoservices.ign.fr/rgealti#telechargement5m
Norway
Various resolutions are available for Norway. 1m, 10m, 50m DTMs and DOM (Digital Orthophoto Maps)
https://hoydedata.no/LaserInnsyn2/