What to do when SOS reports no NAVD88 datum?

[rsignell-usgs]

When comparing observed and modeled water levels, what should we do when the SOS service provides no NAVD88 datum?

It would be great if there was a web service we could call to get the difference between NAVD88, MSL, MLLW and other datums where known at gauge locations (e.g. a web service into the data on pages like these:
http://tidesandcurrents.noaa.gov/benchmarks.html?id=8447930&type=

                            T I D A L   D A T U M S 


Tidal datums at WOODS HOLE, BUZZARDS BAY based on:

     LENGTH OF SERIES:      19 Years
     TIME PERIOD:           January 1983 - December 2001
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:   


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     HIGHEST OBSERVED WATER LEVEL (09/21/1938)         =  3.287
     MEAN HIGHER HIGH WATER                     MHHW   =  0.672
     MEAN HIGH WATER                            MHW    =  0.588
     North American Vertical Datum              NAVD88 =  0.415
     MEAN TIDE LEVEL                            MTL    =  0.315
     MEAN SEA LEVEL                             MSL    =  0.300
     MEAN LOW WATER                             MLW    =  0.043
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (02/02/1976)         = -0.995

@ mchaouchi, do we have a service for this already?

[ebridger]

CO-OPS has a very nice SOAP web service which returns this data for station ids.
http://opendap.co-ops.nos.noaa.gov/axis/ See the Datums examples.

[kknee]

Anyone know if VDATUM has a web service of their conversion grids. Would be nice to get more site specific than the NOAA water level stations.

[rsignell-usgs]

@kknee, that's a great idea! I'll ping Ed Myers and see what he thinks.

[rsignell-usgs]

@emyersnoaa, I know we can't do this tomorrow, but what do you think about developing vdatum as a web service?

It would be cool if someone could submit a URL like:

http://co-ops.noaa.gov/vdatum?lat=[42.5,43.2]&lon=[-69.0,-69.2]&units=m&format=CSV

or something, have Vdatum run on the server and get back a result (CSV in this case) with the Vdatum results at those points.

[emyersnoaa]

The VDatum team had been looking at setting up a web service years ago, but unfortunately that capability never was completed. I will use this as an opportunity, though, to mention this idea to the program manager as something the team should look at developing again. So, at this time, VDatum still needs to be downloaded as software and can then be run either as a GUI or from the command line.