Accession Number:

ADA162210

Title:

Probability and Conditional Probability of Cumulative Cloud Cover for Selected Stations Worldwide.

Descriptive Note:

Final rept. Dec 83-Jul 85,

Corporate Author:

OPTIMETRICS INC BEDFORD MA

Report Date:

1985-07-01

Pagination or Media Count:

229.0

Abstract:

Cloud cover has a major impact on both visible and infrared electro-optical sensors. Climatological statistics of the probability of cloud cover would be useful to tactical commanders planning missions over hostile or contested territory where observations are unavailable. This report presents tables of the historical probability, by okta, of cumulative cloud cover at or below 15 given altitudes. The data consist of routine surface weather observations from the ETAC DATSAV database. Out of 41 stations considered from four regions Germany, Korea, the Middle East, and Central America, 29 stations had data suitable for analysis. Analyses performed for each station were broken down by season and time of day 0000 to 0559, 0600 to 1159, 1200 to 1759, and 1800 to 2359 local time, then averaged separately over season and over time of day, and over all seasons and times of day. Graphical and tabular results are presented for all stations for the average over all seasons and time of day and for a selected station Bitburg, West Germany averages by season and time of day are given. The full set of tables is available on tape. Another goal is to answer the question suppose that a remote measurement indicates that a cloud is or is not present at or below a given altitude, how much additional information does this measurement add to the historical probabilities--i.e. how much different are the conditional probabilities of cumulative cloud cover given that a cloud is or is not reported compared to the unconditional historical probabilities Tables of these conditional probabilities are presented.

Subject Categories:

  • Meteorology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE