SEPTA is installing a Positive Train Control (PTC) System on its Commuter Rail System. These project specifications called for the physical survey of all of the data and information necessary to design the PTC system. The data acquisition and base mapping obtained for this project were required to comprise a geographically and coordinately intact database, which could be utilized to implement the Positive Train Control System.
As part of our scope, RAS obtained low altitude photography to cover a width of 1800′ along the flight paths over all SEPTA right-of-way in full stereoscopic coverage. Data files for planimetric drawings were prepared for 1″=20′ scale and provided in AutoCAD and GIS formats in Pennsylvania State Plane Coordinate System, NAD83, and NAVD88.
All visible features were mapped in addition to significant break lines, approximate centerlines of swales and/or ditches, tops and bottom of banks to the limits of the SEPTA right-of-way in open areas. All features were located to an accuracy of no less than 0.10′ vertically and horizontally. Digital Ortho Photographs were provided at a scale of 1 “=200’. RAS also obtained LlDAR data by high-rail mounted equipment in order to extract features obscured from the aerial photography