Evaluation of Low-Cost Radiometer for Surface Reflectance Re-trieval and Orbital Sensor’s Validation
Thesis - Open Access
Master of Science (MS)
Department / School
Electrical Engineering and Computer Science
Arable Mark 2, Cross-Calibration Gain, Landsat 8, Level 2 Validation, Low-Cost Radiometer, Surface Reflectance Calibration
This paper evaluates the Arable Mark 2 sensor, an automated and low-cost radiometer, for its potential to retrieve surface reflectance data and validate orbital sensors such as the Landsat-8 (L8) Operational Land Imager (OLI) Level 2 product. While orbital sensors are widely used for monitoring solar radiation changes, managing natural resources, and understanding climatic trends, atmospheric effects can make it challenging to obtain accurate measurements. Equipped with multiple sensors, including long-wave and short-wave radiometers, the Arable Mark 2 sensor can measure upwelling and downwelling irradiance to calculate surface reflectance. To assess the accuracy and consistency of the Arable Mark 2 sensor, the study performed a cross-calibration using a ground truth measurement collected with the Analytical Spectral Device (ASD) as the reference point. Additionally, a spectral band adjustment factor (SBAF) was applied across the calibrated Arable surface reflectance to compare it against the orbital sensor. An automated library aided in calculating SBAF for the days with unavailable hyperspectral data. The study found that the Arable Mark 2 sensor can provide accurate surface reflectance data that can be used for orbital sensor validation. The Arable sensor was successfully calibrated against the ASD FieldSpec with a bias of less than 1/10 reflectance unit for the blue, green, yellow, and red bands. The red-edge and NIR-1 bands showed a bias of less than 1/2 reflectance units, while the NIR-2 band had a bias of less than 1/10 reflectance unit of calibration accuracy. The calibrated Arable surface reflectance data was then compared against orbital sensor surface reflectance data, and the results showed good agreement between the two datasets. The study concludes that the low-cost and automated nature of the Arable Mark 2 sensor makes it a promising tool for surface reflectance retrieval and orbital sensor validation.
South Dakota State University
Siriwardana Pathiranage, Dinithi, "Evaluation of Low-Cost Radiometer for Surface Reflectance Re-trieval and Orbital Sensor’s Validation" (2023). Electronic Theses and Dissertations. 585.
Available for download on Monday, November 06, 2023