tailieunhanh - Application of passive remote sensing to investigate transmissivities of trees canopies using ground based upward looking microwave radiometers

This paper presents the results of the study on emission and transmissivity of trees canopyusing ground-based upward-looking microwave radiometers at two bands, L and X which were manufactured and calibrated byour research group at the Space Technology Institute - Vietnam Academy of Science and Technology. | Vietnam Journal of Science and Technology 55 (6) (2017) 767-779 DOI: APPLICATION OF PASSIVE REMOTE SENSING TO INVESTIGATE TRANSMISSIVITIES OF TREES CANOPIES USING GROUND-BASED UPWARD-LOOKING MICROWAVE RADIOMETERS Doan Minh Chung1, K. G. Kostov2, Vo Thi Lan Anh1, Huynh Xuan Quang1, Tran Tuan Anh3, Mai Thi Hong Nguyen1, *, Le Dai Ngoc3 1 Space Technology Institute,Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Ha Noi, Viet Nam 2 Institute of Electronics, Bulgarian Academy of Sciences, 72 Tzarigradsko chause- Sofia1784, Bulgaria 3 Defense Mapping Agency of VietNam, Ministry of Defence, 2/198 Tran Cung, Co Nhue, Tu Liem, Ha Noi, Viet Nam * Email: mthnguyen@ Received: 10 October 2016; Accepted for publication: 13 May 2017 Abstract. In Vietnam, in recent years, remote sensing technology has developed very strongly in many different application areas. Besides, remote sensing using optical satellite, radar satellites, passive remote sensing includingmicrowave radiometers has been studied for a long time. This paper presents the results of the study on emission and transmissivity of trees canopyusing ground-based upward-looking microwave radiometers at two bands, L and X which were manufactured and calibrated byour research group at the Space Technology Institute Vietnam Academy of Science and Technology. In the field measurement campaigns in 2015 and 2016, brightness temperatures were calculated from the output signal of the radiometers that measure trees canopy, transmissivity of the canopy in L-band, and X-band was calculated from the physical temperature of the canopy,the brightness temperature of blue sky and the brightness temperature of the canopy after the radiometers were calibrated using blue sky and the black body at the corresponding frequency base on transmissivity model. These results provide empirical evidence to quantify the characteristics of microwave which is transmitted in the canopy .