Wireless laser spectroscopic sensor node for atmospheric CO_2 monitoring-laboratory and field test

摘要

We developed a low-power, portable, wireless laser spectroscopic sensor for atmospheric CO_2 monitoring. The sensor is based on tunable diode laser absorption spec-troscopy with a 2-μm wavelength VCSEL as a source and wavelength modulation technique for spectroscopic signal detection. The sensor allows measurement of CO_2 concentration changes with a 1σ sensitivity of 0.14 ppmv Hz~(-1/2). This sensor was both laboratory and field tested under varying environmental conditions. It was used to measure a soil respiration rate of topsoil in the lab and of forest floors in the field. Measurement results are compared with those of commercial non-dispersive infrared sensors and very good agreement is found.