METEOROLOGICAL TABLES AND CHARTS
GENERAL TABLES AND CHARTS FOR METEOROLOGICAL MESSAGES
a. Section I, General Tables and Charts for Meteorological Messages. These tables and charts are used in computing data for visual ballistic and computer meteorological messages.
b. Section II, Tables for Type 3 Ballistic Messages for Surface-to-Surface Trajectories. These tables include the weighting factors and the weighted quantities for density, winds, and temperatures pertaining to all artillery weapons firing at terrestrial targets.
For convenience in computing, reporting, and applying corrections, the standard atmosphere is further identified by dividing it into zones for standard heights. The zones for the various meteorological messages are illustrated in figure 2-1.
b. In this formula, D is the arc distance of the Earth's surface in meters and q is the elevation angle to a balloon at a standard height H. R is the average radius of the Earth, 6,367,650 meters.
The millibars of pressure for a certain number of inches of mercury may be determined from chart 2-1.
The conversion of surface pressure in millibars to percent of the standard mean sea level pressure is accomplished by use of chart 2-2.
The virtual temperature tables (table 2-2) are computed for an assumed station pressure of 990 millibars (mb), this being approximately the average station pressure for most areas of the United States. These tables, without correction for pressure differences, are appropriate for all artillery applications. Computations for the tables were made using table 72 (Virtual Temperature Increment of Saturated Air), Smithsonian Meteorological Tables, Sixth Edition 1951 and the Relative Humidity-Psychrometric Tables, US Department of Commerce, Weather Bureau 1953.
TABLES FOR TYPE 3 BALLISTIC MESSAGES FOR SUFACE-TO-SURFACE TRAJECTORIES
The tables and charts in this section contain the weighting factors and the weighted quantities for density, winds, and temperatures pertaining to all artillery weapons firing surface-to-surface.
The conversion of surface temperature to percent of standard surface temperature is accomplished by use of chart 2-3.
The percent of standard mean surface density for a particular height in meters may be determined from chart 2-4.
a. The weighted wind speed tables may be, used to convert zone winds to the weighted effect of these winds on the various line values of the meteorological message.
b. The Line-Zone Number values are the product of zone wind values and the weighting factor values shown in table 2-9. The values of Line-Zone Number 21 are the product of zone wind speeds and the weighting factor (.20), line 2 of Zone Number 1, table 2-9.
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