ARS | Publication request: Lidar Based Particulate Flux Measurements of Agricultural Field

Submitted to: Meeting Proceedings
Publication Type: Proceedings/Symposium
Publication Acceptance Date: July 11, 2008
Publication Date: July 11, 2008
Citation: Wojcik, M.D., Bingham, G.E., Marchant, C.C., Zavyalov, V.V., Ahlstrom, D.J., Moore, K., Wilkerson, T.D., Hipps, L.E., Martin, R.S., Hatfield, J.L., Prueger, J.H. 2008. Lidar Based Particulate Flux Measurements of Agricultural Field. International Geo. and Remote Sensing Symposium. Meeting Proceedings. CD-ROM.

Technical Abstract: A three-wavelength portable scanning lidar system was developed to derive information on particulate spatial aerosol distribution over remote distances. The lidar system and retrieval approach has been tested during several field campaigns measuring agricultural emissions from a swine feeding operation, almond orchard harvesting, and cotton gin processing. Results verify the ability of lidar measurements to quantitatively characterize particulate emissions and the spatial and temporal variations of the emitted plume as 3-D/2-D mass concentration fields. Aglite uses an integrated approach to retrieve particulate mass concentration, fusing together in-situ and remote measured data. The retrieval of optical parameters from a three-wavelength lidar, coupled with a minimum least-squares solution, was found to be a valid method for retrievals of mass concentration in aerosol plumes. In-situ measured data are used as boundary conditions for lidar retrievals, to determine the parameters of the lidar equation, and to establish a calibration factor, the MCF, for converting lidar data to mass concentration. The aerosol components during field experiments included background aerosols, emissions from agricultural facilities, and fugitive dust from unpaved roads. Calibration and validation data are derived from TSP, PM10 and PM2.5 samplers and OPC sensors. A simple calibration procedure has been developed to convert the particle size distribution as measured by the OPCs to mass concentration units. Collocated MiniVols sampler measurements and run time averaged OPC data from several locations are used to calculate a mass conversion factor for particles in the background and emitted plume. This MCF is then used to convert the OPC and lidar data to different fractions of mass concentration. The values of particulate emission mass concentration measured by the lidar agree with measurements by point-sensor instruments within the stated error bounds for all three experiment sights.