Dakota Henke EECS /9/2014

Purpose and Applications  UAV-Based Radiometer UPC  Why UAVs? Pros Cons  Soil Moisture and Water Salinity Measurements Agricultural Coastal

System Design  L-Band (1.4 GHz)  Altitude (< 300 m)  Max Air Speed - 45 m/s  GPS and IMU  Dicke Radiometer Balanced - Tref ~ 315 K  Hexagonal Antenna Beamwidth - 22° Gain dB Efficiency %  Nadir Looking  Bandwidth - 27 MHz  Rcv Noise Temp ~ 790 K  Integration Time ~ 100 ms  Theoretical Temperature Resolution ~ 1.27 K  Calibration (Hot/Cold)  Sampling Rate - 50 Hz

System Analysis/Data Processing  Multiple Passes Weighted Sums Varying Resolutions  Pre/Post-Flight Calibration ‘a(t)’ and ‘b(t)’ Hot Sensitivity 0.84 K Cold Sensitivity 1.22 K  Ignore Cosmic & Downwelling Atmosphere Radiation (relatively constant)  Upwelling and Scattered Radiation ~ 0 K, L ~ 0 dB

Soil Moisture  Dielectric constant vs. Water Content Transisition Point  First 5 cm of soil  Surface Roughness  Incidence Angle  Contribution from vegetation (b-factor)

Experimental Results

References  Kerr, Y.H.; Waldteufel, P.; Wigneron, J.; Martinuzzi, J.; Font, J.; Berger, M. Soil Moisture Retrieval from Space: The Soil Moisture and Ocean Salinity (SMOS) Mission. IEEE Trans. Geosci. Remote Sens. 2001, 39,  Valencia, E.; Acevo, R.; Bosch-Lluis, X.; Aguasca, A.; Rodriquez-Alvarez, N.; Ramos- Perez, I.; Marchan-Hernandez, J.F.; Glenat, M.; Bou, F.; Camps, A. Initial Results of an Airborne Light-Weight L-Band Radiometer. Proceedings of the IEEE International Geoscience and Remote Sensing Syposium 2008, Boston, MA. USA, 2008; pp. II II-1179  Van de Griend, A.A.; Wigneron, J. The b-Factor as a Function of Frequeycny and Canopy Type at H-Polarization. IEEE Trans. Geosci. Remote Sens. 2004, 42,  Acevo-Herrera, R.; Aguasca, A.; Bosch-Lluis, X.; Camps, A. On the Use of Compact L- Band Dicke Radiometer (ARIEL) and UAV for Soil Moisture and Salinity Map Retrieval: 2008/2009 Field Experiments. In Proceedings of the IEEE International Geoscience and Remote Sensing Symposium 2009, Cape Town, South Africa, 2009; pp IV729- IV732.  Wang, J.R.; Schmugge, T.J. An Empirical Model for the Complex Dielectric Permittivity of Soils as a Function of Water Content. IEEE Trans. Geosci. Remote Sens. 1980, 18,  Escorihuela, M.J.; Kerr, Y.H.; de Rosney, P.; Wigneron, J.; Calvet, J.; Lemaitre, F. A Simple Model of the Bare Soil Microwave Emission at L-Band. IEEE Trans. Geosci. Remote Sens. 2007, 45,  Acevo-Herrera R, Aguasca A, Bosch-Lluis X, Camps A, Martínez-Fernández J, Sánchez-Martín N, Pérez-Gutiérrez C. Design and First Results of an UAV-Borne L- Band Radiometer for Multiple Monitoring Purposes. Remote Sensing. 2010; 2(7):