BUILDING LASER-SCAN AND PHOTOGRAMMETRIC IMAGE MAPS AND MODELS FOR PRESENT AND BURIED TRACKSITES AT DINOSAUR STATE PARK, ROCKY HILL CT

Terrestrial laser scanning (TLS) with powerful new digital-photogrammetric (PG) techniques are increasingly used to visualize and analyze surface topography for a wide range geologically significant sites. We are using TLS and PG to map, model, and measure the character of the Eubrontes tracksite at Dinosaur State Park (DSP) in Rocky Hill, CT. Some 600 tracks are within an enclosed interpretive center (IC), while an additional ≈1500 tracks occur adjacent to IC buried beneath ≈2.5 m of protective fill. This tracksite was photographed following discovery in the 1960’s and then covered. We utilize scans and imagery: for the IC tracksite a Trimble VX spatial station to define a local coordinate system, survey ground control points (GCP), and scan a ≈0.9 cm spaced point cloud for the tracksite. Approximately 110 near-vertical and overlapping full-frame images with GCP were collected from a 7.6 m tall pole-platform and used to build an image-map. Also ≈500 full frame images of tracks at 12 sites in the IC were collected and processed with Agisoft Photoscan to create point clouds (≈0.1 cm point spacing) and 3D models. Similar data processing of historical images of the buried tracksite is ongoing. These efforts produced an educational poster for the park and several prototype physical models (3D prints) of selected tracks. The poster includes a rectified image-map of the IC tracksite that is superimposed on an older hand-drafted map used for paleontological studies and to identify individual tracks. DSP staff have commented on the value of presenting both types of maps together as an illustration for school groups of the cumulative nature of science. Our data will be used to create down-sized 3D prints of Eubrontes models that require less materials for school groups to cast. We are also using PG data to help the park produce a 1.5x1.5 m section of the tracksite for a life-sized display that children visitors can unearth and walk on. We will also compare conventional caliper-based measurements for individual tracks identified in the hand-drafted map with similar TLS and PG measures. This will quantify the reliability of digital measurements which may be more feasible for some tracksites. Finally, it will be exciting to share our initial efforts to visualize the original DSP discovery site which was buried nearly 50 years ago.