This dataset contains soil moisture sampling protocols and calibration algorithms for Campbell Scientific Hydrosense-I and II units used at burned and unburned sites in the ABoVE project domain. The soil moisture sampling protocols document provides guidance for sampling in situ soil moisture to relate to synthetic aperture radar (SAR) data collections. Two additional documents describe algorithms for calibrating handheld Hydrosense units used to measure volumetric water content in soils. One calibration document applies to organic soils in fire-affected sites of the Northwest Territories and Alaska. A second document provides calibrations for samples collected in non-burned tundra, boreal bog, fen, upland deciduous and conifer sites located in Alberta and tundra sites in Alaska. The information is provided in portable document format (PDF).