How to Change Absolute Cell Reference based on a couple of conditions

I have a workbook that contains a column, G, which includes a formula that calculates distances (based on lat, long coordinates) to a training site ("TS" going forward) from other sites within the same district as that TS.
There are numerous TS's in the company, usually 1 per district (but some districts do not have a training site), and I am trying to find a way to change my distance formula that will automatically detect which site is a TS, and then calculate the distances of those other sites in that same district to their respective TS's.

As it stands, I have to manually change an absolute cell reference every time I encounter one of these TS locations in the file (designated by a "TS" in Col F), and rerun the distance formula down the column.
I would hate to have to do this several hundred times.


Attached is a sample file.
Again, Col G contains the formula for distance calculation, and you will notice that the absolute cell references change each time a TS is encountered -- I have been doing this manually.
Additionally, I would be curious to know if there is a way to spot any Districts that lack a TS, as in District 493, and specify that in Col G.


I would be eternally grateful for any assistance provided.