Modify Google Earth Viewshed Radius
One of the tasks Google Earth Pro is really useful is getting a quick idea of the viewshed from a specific location. This is particularly useful for planning solar installations or other infrastructure projects such as LoRaWAN gateway deployments.

Whilst the tool is quite powerful, it has a very limited viewshed (roughly 5km) and this is not really useful when looking at gateway deployments that in flat regions of Australia easily can reach 25km+. Also it is not at all obvious how to modify the radius of the viewshed since that has not been a feature in the GUI and it is not documented at all.
Enable GeoIP lookups on CentOS
GeoIP enables you to identify the location, organization, connection speed, and user type of your website visitors.
yum install GeoIP mod_geoip
cd /usr/share/GeoIP/
wget http://geolite.maxmind.com/download/geoip/database/GeoLiteCountry/GeoIP.dat.gz
wget http://geolite.maxmind.com/download/geoip/database/GeoLiteCity.dat.gz
gunzip GeoIP.dat.gz
gunzip GeoLiteCity.dat.gz
rm -f *.gz
Edit the VirtualHost settings in httpd.conf
<ifmodule mod_geoip.c>
GeoIPEnable On
GeoIPDBFile /usr/share/GeoIP/GeoIP.dat Standard
GeoIPDBFile /usr/share/GeoLiteCity.dat Standard
</ifmodule>
Restart Apache
/etc/init.d/httpd restart