Abstract: An improved method for correlating between targets in an air traffic control system. A methods or systems according to the invention compare selected components of a first target report to the components of a second target report, produce a confidence level on each component comparison, and determine whether to declare the targets similar based on the confidence level on each component compared. The first and second target reports may include ADS-B target reports and TIS target reports. The individual components of the reports may be range, bearing, track angle, and relative altitude. The methods or systems may use a fuzzy logic probability model to produce a continuous confidence level on each component comparison.

Abstract: Systems, devices and methods are provided to integrate navigation data, such as GPS navigation data, with Personal Digital Assistant (PDA) expense reporting functions to flexibly, accurately and efficiently determine travel distances for expense reports. One aspect provided herein is a method of using a Personal Digital Assistant (PDA) to provide travel expenses for an expense report. Navigation data is used to determine a travel distance, which is associated with a PDA expense report entry. In one embodiment, a procedure for determining a travel distance is selected. One procedure involves calculating a route between a starting location and an ending location. Another procedure involves determining a distance along a track log between the starting location and the ending location. Another procedure involves incrementing a counter to monitor a distance traveled from the starting location. Other aspects are provided herein.