Pressing flowers between pages…
This dataset is a time-series of high-resolution visible and near-infrared imagery of the Gothic Townsite area surrounding Rocky Mountain Biological Laboratory, collected by an Uncrewed Aircraft System (UAS, e.g. "drone"). Image data was captured by a Micasense Altum v1 multispectral and thermal sensor attached to a quadcopter aircraft flying at 100m above the ground surface. Data has a nominal ground sample distance (pixel resolution) of approximately 5 cm, but has not been resampled from its original resolution to preserve data quality. Values represent apparent directional reflectance (proportion of reflected light) multiplied by 10000 and stored as 16-bit integers. This means that a value of 10000 represents a reflectance of 1.0000. Band order for the imagery is as follows: Band 1: Blue (center 475 nm, bandwidth 20 nm) Band 2: Green (center 560 nm, bandwidth 20 nm) Band 3: Red (center 668 nm, bandwidth 20 nm) Band 4: Near-IR (center 840 nm, bandwidth 40 nm) Band 5 Red Edge (center 717 nm, bandwidth 10 nm) Note that the bands are not in wavelength order (NIR appears before Red Edge), consistent with the band order of the Altum raw data. Thermal IR images representing radiometric surface temperatures were also captured by the sensor at the same time as the multispectral data, but these lower-resolution datasets are shared as a separate time-series. Flights were conducted approximately weekly within 3 hours of solar noon, in full-sun conditions where possible. The flights typically take approximately 75 minutes to complete, and flightlines were oriented NNW-SSE at a 28m spacing, starting in the western proportion of the imaging area and progressing east. This means that western parts of the imaging area were typically imaged approximately 1-hour beore the eastern edges. Raw images were captured as 16-bit TIFF files approximately once every 1.2 seconds, providing approximately 75 percent forward overlap and 70 percent side overlap between adjacent images. For densely forested parts of the landscape, the forward speed of the aircraft was reduced to 8 m/sec to increase the forward overlap to 85%, improving orthomosaic performance for complex vegetation. Raw image data was georeferenced and orthorectified in Agisoft Metashape software (version 1.7), using information from the UAS system's Real-time Kinematic (RTK) global satellite navigation system as well as 8-15 ground-control points geolocated to within 2 cm. Independent assessment indicates a geographic precision of approximately 5 cm (Mean Absolute Error). Radiometric calibration was performed using the sensor's built-in DLS2 light sensor as well as images of Micasense calibration targets taken before and after each flight.
Items connected by shared entities, co-authorship, citations, or semantic similarity.