Visibility Data Filters for Europe
Abstract
The purpose of the report is to present the methodology for filtering the European meteorological visibility data from undesirable and erroneous data. Seven data filters were devised and imposed on the European synoptic visibility data set. The data set consisted of fourteen years of meteorological data (1973- 1986) for about 1600 station in Europe. The European data set was extracted from the DATSAV global weather database maintained by the U.S. Air Force, ETAC, Scott Air Force Base. The raw meteorological data set consisted of over 1000 magnetic tapes containing about 30 gigabytes of data. The first step in the data processing involved compacting the data set into a binary form, which reduced the data size to a 3 gigabytes. Next, from the daily visibility data, the quarterly cumulative distribution functions for extinction coefficient B(ext) an visibility were computed. Most of the subsequent data filtering was performed using the distribution functions and the Voyager data exploration software. The data cleaning filters fell into three categories: (1) precipitation and humidity filters, (2) filters based on the year to year fluctuation of extinction coefficient, and (3) filters that eliminated entire stations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 14, 1990
- Accession Number
- ADA225985
Entities
People
- Bret A. Schichtel
- Rudolf B. Husar
Organizations
- University of Washington