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The CSIR-NLC Mobile LiDAR |
The SERA Remote Sensing Fous Area Team recently presented the first scientific results of the CSIR-NLC Mobile LIDAR, as part of its Light Detection and Ranging (LiDAR) project. The paper was presented as part of the IEEE Geoscience and Remote Sensing Symposium (IGARSS) 2009, from 12-17 July in Cape Town.
This year's event marked the first time that IGARSS has been held on the African continent and represented a milestone in the IEEE Geoscience and Remote Sensing Society's strategic objective to broaden international participation, particularly in the developing countries.
After the initial calibration and tests, the CSIR-NLC LIDAR was operated for the first time on 23 February 2008. The laser was directed vertically upward into the sky and the corresponding night was a cloudy sky. The results detailed in the Remote Sensing team's paper were compared and validated with satellite and photometer measurements. The comparison shows a reasonable agreement with the measurements.
Although ground based LIDAR systems are deployed for atmosphere studies in many developed countries, it is still a very novel technique for South Africa and African countries. There are currently two different LIDARs available in South Africa, located in Pretoria and Durban respectively. Both LIDAR systems have similar specifications which permits the establishment of simultaneous aerosol measurement studies. The Durban LIDAR is operated at University of KwaZulu-Natal as part of cooperation between the Reunion University and the Service d'Aéronomie (CNRS, IPSL, Paris) for climate research studies. It allows for studying the stratospheremesosphere (30-80 km) thermal structure and tropospherestratosphere aerosol (8-40 km).
The CSIR's mobile LIDAR system was designed and developed to contribute towards atmospheric research in South Africa and African countries. It acts as an ideal tool for making aerosol or particulate measurements over Southern Hemisphere regions and this will encourage collaboration with other partners' in terms of space-borne and ground based LIDAR measurements. At present, the system is capable of providing vertical aerosol or cloud backscatter measurements for the height region from ground to 40 km with a 10 m resolution.
The major advantage of the LIDAR is that it provides the vertical cross-section of cloud including the thickness which is important for better understanding the cloud dynamics and the earth-radiation budget. The LIDAR measurements will also elucidate the aerosol concentration, optical depth, cloud position, thickness and other general properties of the cloud which are important for a better understanding of the earth-radiation budget, global climate change and turbulence.
The team's future plans include conducting field campaign measurements in and around South Africa, qualitative industrial pollutant measurements, 3-D measurements using an XY scanner, a two channel LIDAR system, water-vapour measurements, the implementation of Differential Absorption LIDAR (DIAL) and ozone measurements.
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