{'fraction_non_alphanumeric': 0.027385892116182572, 'fraction_numerical': 0.0016597510373443983, 'mean_word_length': 5.380952380952381, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Development and operational testing of a sub-meter Positive Train Location system

Leidos has developed an operational test-ready navigation system for Positive Train Location (PTL) demonstrating position accuracies that enable cross-track discrimination using low-cost onboard components and no trackside infrastructure. The system combines information from multiple sensors and a track database (when available) in the Leidos Embedded Data-fusion Geospatial Engine (EDGE) sensor fusion algorithms to create optimal state estimates for position, velocity, and attitude. In Phase I of the PTL development effort, Leidos tested a proof-of-concept system using both simulation and real-world track testing at the Transportation Technology Center (TTC) test track in Pueblo, Colorado. The system demonstrated position errors less than 20 cm in the along-track and across-track axes as measured by a fixed-base station Real-Time Kinematic (RTK) GPS reference system. In Phase II, the hardware has been redesigned to support operational railroad installation and testing. The production design has been tested at both the TTC test track as well as on United States Class I railroad operational track territory.