(Link to Metadata) This metadata record describes the acquisition and production of 30 centimeter ground sample distance (GSD) natural color and color infrared digital ground orthoimagery covering a portion of Vermont State, which were used to derive greyscale (black and white). The digital orthophotography and color infrared digital orthos are composed of 24 bit natural color digital orthos with a 0.3 meter GSD. Geographic extent includes portions of Addison, Chittenden, Orange, Rutland, Washington, and Windsor Counties in central Vermont, approximately 1,222 total square miles. Poor weather and ground conditions precluded capture of all areas originally planned. Product: 30-centimeter black and white orthoimagery tiles (uncompressed GeoTIFF and compressed JPEG2000) derived from original color orthoimagery tiles. Geographic Extent: The acquisition included portions of Addison, Caledonia, Chittenden, Orange, Rutland, Washington, and Windsor Counties in central Vermont, approximately 1,222 total square miles. Poor weather and ground conditions precluded capture of all areas originally planned. Dataset Description: The Vermont 2017 Imagery project called for the planning, acquisition, processing and derivative products of imagery data to be collected at an ground sample distance of 30 centimeters.Project specifications are based on the ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014). The data was developed based on a horizontal projection/datum of NAD83 (2011), State Plane Coordinate System Vermont, meters and vertical datum of NAVD1988 (Geoid 12A), meters.Raw imagery data was produced in 16-bit 4-band (RGB-IR) uncompressed format, then processed to create 24-bit 4-band (RGB-IR) orthorectified tiles. Compressed orthoimagery was produced in JPEG2000 format. An additional set of uncompressed GeoTIFF and compressed JPEG 2000 data was produced in black and white. A total of 977 of the originally planned 1,759 tiles were produced with a tile size of 1,800-meters x 1,800 meters. Tile names use the following naming convention "VT_(TILENUM)_(YYYYMMDD).(FileExtension)", where TILENUM = the 6-digit value of the TILENUM attribute in the master index files and YYYYMMDD = the flight acquisition date (or majority date) for that particular tile. Ground Conditions: Imagery was collected in spring of 2017 during minimal shadow conditions. In order to post process the imagery data to meet task order specifications, Quantum Spatial utilized 8 checkpoints provided by the Bryant Associates, Inc. These checkpoints were established throughout the project area and used to check the accuracy of the data.
