Attached is a document describing the requirements for GRUAN station regarding the pre-launch procedures for routine soundings with Vaisala RS92 radiosondes. In order to obtain high data quality, ensure long term stability, and to make sure that measurement uncertainties are within the ranges that are reported in the product files, it is important that some ground checks are made before launch in the way described in this document and that the meta-data are reported to the GRUAN lead centre.
Protected: GRUAN recommendation for radiosonde pre-launch QC (this discussion is currently within Task Team 1 members only)2011-02-04
The paper “A guide for upper-air reference measurements” by F. Immler, J. Dykema, T. Gardiner, D. N. Whiteman, P. W. Thorne, and H. Vömel went online on the interactive Journal “Atmospheric Measurement Techniques” where it is open for public discussion for eight weeks (link).
The GRUAN station FMI-ARC in Sodankylä Finland organized an atmospheric sounding campaign in early 2010, which included participants from several countries. The first phase of the campaign was focussing on radiosonde inter-comparisons that were carried out in January-February 2010. Different commercial and research grade in situ instruments were launched with a focus on the comparison of humidity and temperature measurements in the troposphere and stratosphere.
The following paragraphs from an e-mail by John Dykema describes how co-location and coincidence could be formalized. As an example, the measurements of a temperature profile by a sensor on a balloon and a profile retrieved from microwave radiometry are assumed.
Once we have two well-characterized sensors with rigorously assessed and validated uncertainties, then we can make robust recommendations on co-location.