Smith Sandwell missing files

[mdsumner]

ftp://topex.ucsd.edu/pub/global_topo_1min/

Apr 27 2016 00:00         1625 README_PERMISSIONS.txt
Jan 14 2019 19:44        16987 README_V19.1.txt
Jan 14 2019 19:44         8022 REFERENCES_V19.1.txt
Oct 16 2007 00:00         8248 arcinfo_2min.html
Aug 27 2007 00:00    Directory gmt_examples
Jul 25 2012 00:00      2851712 survey_tool.zip
Jan 14 2019 19:42    746496000 topo_19.1.img
Sep 17 2008 00:00          822 topo_19.1.img.ers

we are missing a couple of files, particularly "topo_19.1.img.ers"

#./global_topo_1min$ 
ls | grep 19
README_V19.1.txt
REFERENCES_V19.1.txt
topo_19.1.img