A Revisit of the Field Artillery's Time-Space Wind Variability Equation

Abstract : The U.S. Army has derived artillery accuracy error budgets based on a time & space ballistic wind variance formula. The wind algorithm uses a midlatitude wind profile to derive the expected ballistic wind component variance. This time variability equation is reevaluated using 190 hourly upper air profiler soundings collected over Platteville, CO, representing 8 days of diverse weather conditions. Comparisons between the computed ballistic wind time variability and the equation estimated variability reveal the formula to be an unbiased estimator with 1 kn precise agreement at a staleness of 1 h. The equation accuracy ranges from 1.5 to 3.0 ballistic kn depending on a time staleness of 2 to 4 h, ballistic line, and season.