Satellite Based Energy Balance for Mapping Evapotranspiration with Internalized Calibration (METRIC) Model
Mapping evapotranspiration at high resolution with internalized calibration (METRIC) is a satellite based image processing model for calculating evapotranspiration (ET) as a residual of the surface energy balance. METRIC uses as its foundation the pioneering SEBAL energy balance process developed in The Netherlands by Bastiaanssen, where the near surface temperature gradients are an indexed function of radiometric surface temperature, thereby eliminating the need for absolutely accurate surface temperature and the need for air temperature measurements. The surface energy balance is internally calibrated using ground based reference ET to reduce computational biases inherent to remote sensing based energy balance and to provide congruency with traditional methods for ET. Slope and aspect functions and temperature lapsing are used in applications in mountainous terrain. METRIC algorithms are designed for relatively routine application by trained engineers and other technical professionals who possess a fami.