[time-nuts] GPS usable for weather forecasting?
phk at phk.freebsd.dk
Sat Mar 30 00:51:24 EDT 2013
In message <5156611D.6090201 at earthlink.net>, Jim Lux writes:
>occultation is pretty heavily used now.. When you talk about weather
>forecasting, they talk about "what percentage of the variance is reduced
>by adding source X", and I seem to recall that for GPS RO it's something
>like 10-15%.. around the 3rd or 4th most useful measurement.
>Also, that whole "stated needs" is a pretty fuzzy thing. [...]
Isn't it always ?
They have a point though: LEO data of all kinds pretty much king
in global weather models these days. ECMWF has a very interesting
artile on page 5 in their latest newsletter:
"Polar-orbiting satellites crucial in successful Sandy forecasts."
>Keeping this somewhat time-nutty... It would be interesting to see what
>kind of measurement performance one could get with cheap GPS receivers
>like they use on cubesats.
The Ørsted satellite used a standard Turbo-rogue receiver in in a
high output-rate mode. Can't remember if it was 10 or 100Hz. I
seem to remember that dual-frequency carrier tracking is the enabling
technology for GPS sounding, but the Øersted papers will give
you all that.
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
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