Summary

Description

This data set is one component of a digital terrain model (DTM) for the Southwest Florida Water Management District's FY2006 Digital Orthophoto (B089) and LiDAR Project (L470/L471), encompassing approximately 1,216 square miles across Citrus and Sumter counties. The 2006 LiDAR dataset is comprised of 3-D masspoints delivered in the LAS file format based on the District's 5,000' by 5,000' grid (1,356 cells). The other DTM component is 2-D and 3-D breakline features in the ESRI ArcGIS Personal Geodatabase format. In accordance with the 2006 SWFWMD Topographic Database Design, the following breakline features are contained within the database: closed water bodies (lakes, reservoirs, etc) as 3-D polygons; linear hydrographic features (streams, canals, swales, embankments, etc) as 3-D breaklines; coastal shorelines as 3-D linear features; edge of pavement road features as 3-D breakines; soft features (ridges, valleys, etc.) as 3-D breaklines; obscured vegetation polygons as 2-D polygons; overpasses and bridges as 3-D breaklines; 1-foot contours for visualization purposes; and island features as 3-D polygons. This data falls in Citrus and Sumter Counties. Intensity values, or the measure of reflectance of the laser are also captured. Breakline features were captured to develop a hydrologically correct DTM. Contours (1-foot) were generated from the DTM that meet the National Map Accuracy Standards for 2-foot contours (FEMA specifications). Bare earth LiDAR masspoint data display a vertical accuracy of at least 0.3-feet root mean square error (RMSE) in open unobscured areas