Research
Groundbased Observations
Real Time GPS Water Vapour
Two dimensional integrated water vapour fields give an insight in
the water vapour distribution. Using the Dutch GPS network NETPOS
and a few EUREF sites a near real time IWV product is created on an
experimental basis.
The IWV product is created every 15 minutes with a delay of
approximately 5 minutes. The latency of the data is comparable to
that of the weather radar and the Meteosat images. The data from
NETPOS is received in 5 minute batches while the EUREF data is
collected using the Ntrip system. The latter transmits GPS data
(raw or RINEX) using streaming which implies that this data is real
time in meteorological sense.
The two dimensional field is created using optimal interpolation
with the background being the previous IWV field. In the animated
gif below the change in IWV is shown. The GPS sites used in the
interpolation are depicted by the circles together with the
observed values.
| South England and The Netherlands |
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| British data courtesy of Ordnance Survey GB
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The animation is updated every 15 minutes. Note that this product is still
very experimental.
