Middlesex County Office of Information TechnologyFor fastest download of the entire dataset, choose file geodatabase. To download a smaller dataset in shapefile format, zoom into your area of interest and download a filtered dataset (this may not be quicker but would save disc space). This dataset contains 2 foot contours for Middlesex County, NJ and was created from LiDAR data collected in April and May of 2017. Data is in NAD_1983_2011_StatePlane_New_Jersey_FIPS_2900_Ft_US, NAVD88 Geoid12B, US survey Feet. LiDAR for this dataset was classified and quality controlled by EagleView. Digital Elevation Models, Contours, and Hydrographic breaklines were generated by Ground Point and subsequently quality controlled by EagleView. LiDAR nominal point spacing was 0.387 meters and point density was 6.674 points per square meter. The RMSEz was computed to be 0.09 meters. AccuracyZ has been tested to meet 18.2 cm Fundamental Vertical Accuracy at 95 percent confidence level using (RMSEz * 1.9600) as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (3DEP)/ASPRS Guidelines. LiDAR data meets USGS Quality Level 2 (QL2) standards. Contours were derived from LiDAR. The contours are created from the DEM. The contours were edited in the following manner: Lines shorter than 18 ft (1.5 raster cells) are removed and the shape of the contour lines along the edge of water ways are checked to make sure they do not weave into the waterways. The contour lines are smoothed using a PAEK algorithm with a 3m smoothing tolerance. Attributes are added for 10ft, 20ft, and 50ft index contours.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/e0bb4c92ac6040e089f29e3f8813d2a9_0engNew Jersey Geographic Information Network (NJGIN) Open Data PortalPublicMiddlesex County NJ 2Foot Contours [New Jersey]Web servicesNew JerseyLast Modified: 2020-08-12