Submitted to: Journal of Applied Remote Sensing (JARS)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/31/2009
Publication Date: 7/15/2009
Citation: Zavyalov, V.V., Marchant, C.C., Bingham, G.E., Wilkerson, T.D., Hatfield, J.L., Martin, R.S., Silva, P.J., Moore, K.D., Swasey, J., Ahlstrom, D.J., Jones, T.J. 2009. AGLITE Lidar: Calibration and Retrievals of Well Characterized Aerosols from Agricultural Operations using a Three-wavelength Elastic Lidar. Journal of Applied Remote Sensing (JARS). 3(1):033522. Available: http://dx.doi.org/10.1117/1.3122363. Interpretive Summary: Measurement of particulates released from agricultural operations is difficult to quantify because of the large variation in these concentrations both in space and time. The use of traditional point samplers measure a single point surrounding a facility or field and may not represent the variation in the dynamics in particulates from agricultural operations. This is a serious shortcoming that limits our ability to provide realistic estimates of the amount of particulates that are released from a facility or agricultural operation. To address this problem a three-wavelength lidar (Light Detection and Ranging) system was constructed for the purpose of measuring the particulate concentration in a plume of air above an agricultural facility. This unit represents an advance in our understanding of particulate measurement and links the point measurements collected with the traditional samplers with the lidar measurements to estimate the movement of particulates. This advance in understanding the complexities of air movement will help scientists collect better information about particulate movement and ultimately be able to compare among different practices that improve air quality.
Technical Abstract: Lidar (Light Detection And Ranging) provides the means to quantitatively evaluate the spatial and temporal variability of particulate emissions from agricultural activities. AGLITE is a three-wavelength portable scanning lidar system developed at the Space Dynamic Laboratory (SDL) to measure the spatial and temporal distribution of particulate concentrations around an agricultural facility. The retrieval algorithm uses simultaneous measurements at three laser wavelengths (355, 532, and 1064 nm) to extract particulate optical parameters, convert these parameters to volume concentration, and estimate the particulate mass concentration of a particulate plume. Quantitative evaluation of particulate optical and physical properties from the lidar signal is complicated by the complexity of particle composition, particle size distribution, and environmental conditions such as heterogeneity of the ambient air conditions and atmospheric aerosol loading. Additional independent measurements of particulate physical and chemical properties are needed to unambiguously calibrate and validate the particulate physical properties retrieved from the lidar measurements. The calibration procedure utilizes point measurements of the particle size distribution and mass concentration to characterize the aerosol and calculate the calibration parameters. The Aglite system is able to map the spatial distribution and temporal variation of the particulate mass concentration (TSP, PM10, PM2.5, and PM1) of an aerosol plume.