This LiDAR data is within Illinois Department of Transportation District 2 and includes Stephenson County, Illinois. The data is updated from its original format to LAS version 1.2. The LiDAR data was collected in March 2009 as 'Stephenson County, Illinois LiDAR Acquisition' - ILDOT Project No. P-30-007-08, PTB 146, Item41. Data was acquired by Quantum Spatial as project 1080110 with an Optech ALTM Gemini sensor equipped with an inertial measuring unit (IMU) and GPS receiver. The acquisition was to produce first return ASCII, bare earth ASCII, DAT and TIN files.