English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We retrieved the total content of the atmospheric water vapor (or IntegratedWater Vapor, IWV) from extensive sets of photometric data obtained since 1995at Lindenberg Meteorological Observatory with star and sun photometers.Different methods of determination of the empirical parameters that arenecessary for the retrieval are discussed. The instruments were independentlycalibrated using laboratory measurements made at Pulkovo Observatory with theVKM-100 multi-pass vacuum cell. The empirical parameters were also calculatedby the simulation of the atmospheric absorption by water vapor, using theMODRAN-4 program package for different model atmospheres. The results arecompared to those presented in the literature, obtained with differentinstruments and methods of the retrieval. The reliability of the empiricalparameters, used for the power approximation that links the water vapor contentwith the observed absorption, is analyzed. Currently, the total (frommeasurements, calibration, and calculations) errors yield the standarduncertainty of about 10% in the total column water vapor. We discuss thepossibilities for improving the accuracy of calibration to ~1% as indispensablecondition in order to make it possible to use data obtained by opticalphotometry as an independent reference for other methods (GPS, MW-radiometers,lidar, etc).

Analysis of the application of the optical method to the measurements of  the water vapor content in the atmosphere - Part 1: Basic concepts of the  measurement technique