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Station Equipment Questions / Re: Meteorological station
« on: July 19, 2018, 12:46:10 PM »
Serna Yebes
I think that all participants on the Networks and Engineering Standing Committee Forum will agree on the following points:
• The coordinates and in particular the height difference between the barometric sensor in use and the telescope invariant point should be included, measured and known in the local geodetic network.
• The sensors (and in particular the barometer, which is the most difficult to calibrate “in situ”) should be calibrated periodically, (how we define “periodic” will be another looooong discussion).
• What is now the sampling data rate of the current Yebes meteorological station?
Most SLR and GPS stations works at 10 minutes (at sharp second) sampling rate.
Remember that the pressure resolution asked is 0.1 milibar, and most of time, the pressure change rate in 10 minutes is less or equal than that.
• The meteodata should be time tagged and available immediately at the local network, not only the last measurement done, but also the proceeding ones.
• This is because the best practice is to include both pre- and post- meteorological values on the Normal point and this Normal Point file should be generated and delivered as soon as possible.
But if you do the “batch filtering” every few hours, you need to have access to the data of at least the last couple of days (to have a monthly file is a good compromise)
• If the “local microclimate” at Yebes is (more or less) the same at the meteorological and SLR places, for example both places are surrounded by grass, this distance is not a problem.
In Riga we are using a common meteorological station at a distance of 32m (GPS) and 50m (SLR)
• Do the current meteorological station has an anemometer?
Do you have strong winds at Yebes?
Because for really strong winds, automatically closing the roof/cupola/clamshell will be a good security measure against flying objects.
At the new buildings at GFZ Potsdam, all the windows have external Venetian blinds connected to a central anemometer. When the wind reaches a limit all the blinds are automatically lowered to protect the windowpanes
• Invest the money on the best clarity/rain sensor in which the rain/snow alarm can be used to automatically close the SLR roof AND on a high quality all-Sky camera!
When several satellites are visible and it is partially cloudy, the all-Sky camera is the best tool for the on-the-spot tracking optimization.
And if you have a LOT of money project, and buy the independent, well calibrated SLR basic meteorological station situated at the SLR invariant height, no one at the SLR community will complain!.
I think that all participants on the Networks and Engineering Standing Committee Forum will agree on the following points:
• The coordinates and in particular the height difference between the barometric sensor in use and the telescope invariant point should be included, measured and known in the local geodetic network.
• The sensors (and in particular the barometer, which is the most difficult to calibrate “in situ”) should be calibrated periodically, (how we define “periodic” will be another looooong discussion).
• What is now the sampling data rate of the current Yebes meteorological station?
Most SLR and GPS stations works at 10 minutes (at sharp second) sampling rate.
Remember that the pressure resolution asked is 0.1 milibar, and most of time, the pressure change rate in 10 minutes is less or equal than that.
• The meteodata should be time tagged and available immediately at the local network, not only the last measurement done, but also the proceeding ones.
• This is because the best practice is to include both pre- and post- meteorological values on the Normal point and this Normal Point file should be generated and delivered as soon as possible.
But if you do the “batch filtering” every few hours, you need to have access to the data of at least the last couple of days (to have a monthly file is a good compromise)
• If the “local microclimate” at Yebes is (more or less) the same at the meteorological and SLR places, for example both places are surrounded by grass, this distance is not a problem.
In Riga we are using a common meteorological station at a distance of 32m (GPS) and 50m (SLR)
• Do the current meteorological station has an anemometer?
Do you have strong winds at Yebes?
Because for really strong winds, automatically closing the roof/cupola/clamshell will be a good security measure against flying objects.
At the new buildings at GFZ Potsdam, all the windows have external Venetian blinds connected to a central anemometer. When the wind reaches a limit all the blinds are automatically lowered to protect the windowpanes
• Invest the money on the best clarity/rain sensor in which the rain/snow alarm can be used to automatically close the SLR roof AND on a high quality all-Sky camera!
When several satellites are visible and it is partially cloudy, the all-Sky camera is the best tool for the on-the-spot tracking optimization.
And if you have a LOT of money project, and buy the independent, well calibrated SLR basic meteorological station situated at the SLR invariant height, no one at the SLR community will complain!.