AIRBORNE RADIOMETER AT L-

BAND (ARIEL)

Dakota Henke

EECS 823

12/9/2014

Purpose and Applications UAV-Based Radiometer

UPC Why UAVs?

ProsCons

Soil Moisture and Water Salinity MeasurementsAgriculturalCoastal

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 - 15.88 dBEfficiency - 96.5%

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 SumsVarying Resolutions

Pre/Post-Flight Calibration ‘a(t)’ and ‘b(t)’Hot Sensitivity 0.84 KCold 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 ContentTransisition 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, 1729-1735.

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-1176-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, 786-794.

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, 288-296.

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, 1978-1987.

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):1662-1679.