Talk:Collocation (remote sensing)
It should be pointed out that the Polarstern radiosondes have an unusually low ascent rate.
According to the WMO CIMO guide (http://w1npp.org/wx1gyx.org/manuals/NOAA_H~1/CIMO/PA5661~0.PDF):
"Radiosondes are usually carried by balloons rising with a rate of ascent of between 5 and 8 m s-1, depending on the specification and characteristics of the balloon in use (see Chapter 10, Part II). These rates of ascent allow the measurements to be completed in a timely fashion - i.e. about 40 minutes to reach 16 km and about 90 minutes to reach heights above 30 km - so that the information can be relayed quickly to the forecast centres. The designs and positioning of the temperature and relative humidity sensors on the radiosonde are usually intended to provide adequate ventilation at an ascent rate of about 6 m s-1. Corrections applied to temperature for solar heating errors will usually only be valid for the specified rates of ascent. "
Actually I'm wondering if much of that discussion shouldn't be changed or removed. The equation was derived assuming the balloon stays in thermal equilibrium with the air, but it would probably be more realistic to assume adiabatic decompression. If this is done, it doesn't work out nearly so neatly. Peteymills (talk) 00:22, 17 December 2013 (UTC)