Heightmap data for elevations are available:

https://www.iea-software.com/ftp/Emeraldv6/geography
https://dds.cr.usgs.gov/srtm/

To install unzip heightmap file(s) to Emerald\heightmaps folder.

Finally click 'Apply' from Emerald Admin menu for change to take effect.

SRTM1 heightmaps have 1 arc-second (30 meter) resolution
SRTM3 heightmaps have 3 arc-second (90 meter) resolution

When downloading 1 degree square heightmaps for Southern latitudes or
Western longitudes please be sure to add 1 to south and or west
dimension. For example to obtain elevations for coordinate North 47.5 by
117.3 West heightmap file covering this is N47W118.

For United States "SRTM1" maps provide more detailed
terrain charting and improve accuracy of path loss prediction.

https://www.iea-software.com/ftp/Emeraldv6/geography/North_America/United_States/Elevations/SRTM1/
https://dds.cr.usgs.gov/srtm/version2_1/SRTM1/

Note: Emerald supports elevation data of any resolution.
Elevations from other sources can be used provided data is first
converted to SRTM HGT compatible format with files partitioned into 
1 degree squares and labeled similarly.
