Propagation and antenna studies using WSPR

Many of you may wonder what the huge amount of data available in the WSPR-DB may be used for...
Just for the newcomers, I am spotting here again some work I have done using the WSPR-data. (just updated)
You may find ideas for you own work. Please spot any propagation, antenna or other related study you may have done using WSPR.

Thanks and best regards - Patrick