HydraProbe Field Portable Used to Validate the Soil Moisture Active Passive Satellite Data in Manitoba

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

Read the full report published in the Journal of Hydrology

Related Articles

Improved Water Supply Forecasts Using Soil Moisture Data

HydraProbe used to improve water supply forecast from 3 SNOTEL sites in Idaho over traditional antecedent conditions using the principle component forecast model Much of the water in the Western United States used for irrigation, municipal supplies and hydro-electric production originates as winter snow pack at higher elevations. Since the early 1900s, the correlation between

Read More »

OSU Researchers Deploy Stevens Equipment in Study of Green Infrastructure Treatment for Groundwater Runoff

Stormwater runoff pollution is a serious issue that faces almost every urban and suburban environment. In older city infrastructure, runoff from roofs, parking lots, and streets flows directly into the sewer system and must be handled by the municipal wastewater treatment facility, increasing the amount of work the system must undertake. For the past 30

Read More »

Calibration of a Capacitance Soil Sensor Required to Achieve the Level of Accuracy Required for Satellite Ground Truthing

This study published in American Meteorological Society’s BAMS journal demonstrates the extent of variability in readings one can expect with a soil moisture sensor based on capacitance technology. To obtain the highest level of accuracy that is required for remote sensing applications, capacitance-based soil sensors often need to be recalibrated. The HydraProbe is an impedance-based

Read More »