TOWARD CALIBRATED MODULAR WIRELESS SYSTEM BASED AD HOC SENSORS FOR IN SITU LAND SURFACE TEMPERATURE MEASUREMENTS AS SUPPORT TO SATELLITE REMOTE SENSING

摘要

This paper presents a new method for in situ Land Surface Temperature (LST) measurements' campaigns for satellite algorithms validations. The proposed method based on Wireless Sensor Network (WSN) is constituted by modules of node arrays. Each of which is constituted by 25 smart nodes scattered throughout a target field. Every node represents a Thermal Infra Red (TIR) radiation sensor and keeps a minimum size while ensuring the functions of communication, sensing, and processing. This Wireless-LST (Wi-LST) system is convenient to be installed on a field pointing to any type of targets (e.g. bare soil, grass, water, etc.). Ad hoc topology is adopted among the TIR nodes with multi-hop mesh routing protocol for communication, acquisition data are transmitted to the client tier wirelessly. Using these emergent technologies, we propose a practical method for Wi-LST system calibration. TIR sensor (i.e. OSM101 from OMEGA society) measures temperature, which is conditioned and amplified by an AD595 within a precision of 0.1 C. Assessed LST is transmitted over the developed ad hoc WSN modules (i.e. MICA2DOT from CROSSBOW society), and collected at in situ base station (i.e. PANASONIC CF19 laptop) using an integrated database. LST is evaluated with a polynomial algorithm structure as part of developed software. Finally, the comparison of the mean values of LST(Wi-LST) in each site with the Moderate Resolution Imaging Spectro-radiometer (MODIS) sensor, obtained from the daily LST product (MOD11C1) developed by the MODIS-NASA Science Team, on board TERRA satellite during the campaign period is provided