Determining the Accuracy of Launch Acceptability Regions

Chiawei Lee, Weapons System Integration Flight, Air Force Flight Test Center, Edwards AFB, CA

Abstract

Background
With the advanced technology in current and future precision guided munitions (PGM), the ability to strike targets with surgical accuracy has become a reality. One of the greatest challenges in air-to-ground weapons delivery is predicting when and where to release these PGMs. The prediction is a balancing act of ensuring the weapon has enough kinetic energy to maneuver to the target while keeping the aircrew and the aircraft at safe distances from enemy air defenses. Any significant deviation from this equilibrium may result in weapons missing their targets or worse, the loss of life and/or aircraft. The aircraft delivery symbology which indicates where the weapon should be released is commonly called the launch acceptability region (LAR). LAR errors arise from the fact that the LAR predicted by the aircraft simulation model is not always up to date with the latest weapon autopilot software, which determines the capability of the weapon. The conditions at release will also affect the time until impact (TUI) of the weapon, which is also outputted by both the aircraft simulation model and the weapon telemetry (TM) model. Accurate TUI information is crucial to friendly troops on the ground which may be in close proximity to the target during close air support (CAS) situations.

Objectives
Previously, error analysis was accomplished by comparing the aircraft LAR (thru information obtained from the HUD) with computer simulation models that were potentially outdated. This paper presents a method of comparing the aircraft LAR model with the LAR calculated by the weapon itself (outputted in TM). The weapon TM is considered the truth source and is, by definition, the most updated model.

Results
The method presented in this paper will provide the warfighter with more accurate aircraft LAR and TUI by using the most up to date truth source. Accurate LAR information will facilitate not only mission planning but also be used in revising tactics training for aircrew to ensure maximum weapons effectiveness, increase aircrew survivability, and minimize collateral damage during CAS. This information will also be invaluable to software designers in refining their models for future aircraft software updates.