Using GPS as a Reference System to Hit a Moving Target

The Affordable Moving Surface Target Engagement (AMSTE) project attempts to develop affordable solutions to the precise moving target surface target engagement problem. Up to this point, most of the error analysis performed for the AMSTE project has been at the error variance level, generating root-sum-square (RSS) total errors from error budgets consisting of constant error variances. In reality, the level of error for both Global Positioning System (GPS) positioning and radar targeting systems is highly dependent upon the given situation (such as the distance between sensor and target, the altitude differences, etc.) This research generates a more comprehensive model of the UPS errors based upon the underlying physics of the situation. It focuses on differential tropospheric errors and multipath, as these are the primary error source in a differential GPS targeting system. In addition to the error model development, a code-based differential GPS and differential ranging approach is implemented in simulation using a Kalman filter. This approach uses GPS measurements collected by each of the sensors and the weapon, and it uses ranging measurements from the sensors to the bomb and the target. Multiple cases are run varying 1) the number of UPS satellite measurements tracked by each receiver, 2) whether or not the common UPS errors are estimated, and 3) whether or not the bomb is tracked with the same radar sensors that are tracking the target. The horizontal DRMS position error during the terminal phase of the bomb trajectory drops from about 6 meters to about 3.5 meters

Self-Control and Forgiveness: A Meta-Analytic Review

In the 12 years since scholars first investigated the link between self-control and forgiveness (Finkel & Campbell, 2001), the literature investigating this relation has grown rapidly. The present article reports a meta-analytic review of this link across 40 independent samples and 5,105 independent observations. In addition, it investigates an array of potential moderators. Results revealed that the overall link between self-control and forgiveness is statistically robust and small to moderate in magnitude (r = .18). Consistent with the prevailing theoretical models, this link is stronger when forgiveness is assessed in terms of low vengeance (resisting retaliation: r = .31) rather than in terms of high benevolence (fostering prosociality: r = .16). Discussion focuses on the potentially crucial role of forgiveness, especially vengeance inhibition, in linking self-control to relationship well-being