On 10/24/2020 00:48, Matthew Shupe - NOAA Affiliate wrote:
> All,
> After a long time I have finally modified the height specification in the radiosonde base station at Summit.  
It is now based on the latest and greatest GPS survey information from Sam and team with the appropriate geoid corrections. 

Recall that back when the station was moved from the Greenhouse to the SMG, the onsite folks updated parameters for the station 
heights and used the wrong height information (not correcting for geoid). Then, after a number of new on-site height measurements
 were made, these seemed to be inconsistent with my understanding of how the station was actually moved. Sam and team did some 
additional measurements and consulted some GPS experts to arrive at the best estimate of current station heights and so those 
are now in the system. I still feel that they are a few meters inconsistent from how operations were before the move.... 
but at this point there is no way that I see to resolve this issue any further. 
>
> I don't think this will be an issue going forward, but there are two points I'd like to highlight to the full group here.  

(1) if/when the sounding station moves in the future, there should definitely be a discussion about that process before any 
adjustments are made to station parameters in the software.  

(2) the Vaisala software appears to be wrong in how they use one
 of the parameters. They define the launch offset as a distance from the base station, however when done this way in the 
software the first measurement height in the files is not correct. However, if the launch offset is based on a difference 
from the GPS antenna then the first height in the files is correct.  This should not matter much to you all, but I just wanted 
to keep you informed. 


>
> Current parameters are:
> Station altitude:  3211.87m
> Launch site offset:  -8.71m (this should be -3.58 if the Vaisala software behaved correctly)
> Surface barometer offset:  -2.57m
> GPS antenna offset:  5.13m
>
> Cheers,  Matt