Hi Olaf,
The installation is done in a directory relative to your top-level RTTOV directory. For example, if your RTTOV directory is ~/rttov/ and you specify “install” (without the quotes) as the installation directory, then RTTOV will be built in ~/rttov/install/.
If this doesn’t work for you, then can you let me know what output you are getting from the build?
Once the compilation is complete you can move the resulting libraries and binaries wherever you want, although to run the test suite (for example to run the tests to ensure the build worked correctly, or to run the example code described in the Quick Start Guide) you need to specify the directory containing the binaries relative to the RTTOV top-level installation directory (this would be install/bin in the example above).
Best wishes,
James