Evaluation of several calibration procedures for a portable soil moisture sensor

摘要: Summary The calibration and validation of remotely sensed soil moisture products relies upon an accurate source ground truth data. primary method providing this is to conduct intensive field campaigns with manual surface sampling measurements, which utilize gravimetric sampling, probes, or both, estimate the volumetric water content. Soil probes eliminate need for labor-intensive sampling. To ensure accuracy these several studies have determined various degrees localized calibration. This study examines six possible techniques using data collected during a campaign conducted in 2012, samples being over 55 fields southern Manitoba, as part Moisture Active Passive Validation Experiment 2012 (SMAPVEX12). use general equation, applied all data, resulted largest error regardless whether linear third order polynomial relationship was established probes. Calibration equations based on texture vegetation land cover reduced error; however, individual each had lowest techniques. Although average bias low techniques, equation calibrate high biases some fields.