This layer represents the grids for available LiDAR data from the State of Iowa. Users will have access to this layer in the side pane when a Location of Interest (LOI) is placed near available records. Coverage encompasses the entire state. The grid polygons were received from the Iowa LiDAR consortium then attributed with URLs linking to the LAS, and ASCII files within the specific tile. When the user selects a tile, the pop-up bubble will show all available data with URLs and title of tile.
This collection consists of ASCII files of bare earth elevations and intensity (x,y,z,i) and, LAS (version 1.0 lidar data interchange standard) binary files that include all 1st and last returns, intensity and bare earth classification.
Horizontal Positional Accuracy
Standard LiDAR Specifications: -Sanborn prepares flight plans as parallel flight lines with at least one cross flight line to assure positional accuracy and quality control. -Sanborn uses only automated filtering for Standard LiDAR products with the following minimum performance for bare earth elevation models: -89% of artifacts or more removed depending on terrain and vegetation -90% of all outliers removed -90% of all vegetation removed -93% of all buildings removed
1.4 meter average point spacing -Scan frequency and angles based on project area terrain and landcover
1 meter RMSE -No independent field verification
FEMA Compliant LiDAR Specifications: -Sanborn flight plans are parallel flight lines with at least one cross flight line to assure positional accuracy and quality control, and collection verified with both kinematic and static collections. -Sanborn uses automated and manual filtering for LiDAR products with the following minimum performance for bare earth elevation models: -90% of artifacts or more removed depending on terrain and vegetation -95% or better of all outliers removed -95% of all vegetation removed -98% of all buildings removed
In addition to Standard LiDAR specifications: -Sanborn field verification -3 classes, 20 pts. each
Vertical Positional Accuracy
Standard LiDAR Specifications: +/- 18 cm
Bare Earth: 18.5 cm RMSE Vegetation: 37 cm RMSE