LiDAR Calibration Lights Up Durban SkiesGeneral

(Left): the LiDAR laser beam in the process of calibration. (Right) With an LiDAR system are (from left): UKZN’s Mr Ameeth Sharma, Professor Sivakumar Venkataraman, Ms Priyanka Singh, Dr Barbara Duigan, Ms Constance Mphula, Ms Senamile Sithole, and Dr Ruchith R Devaki.(Left): the LiDAR laser beam in the process of calibration. (Right) With an LiDAR system are (from left): UKZN’s Mr Ameeth Sharma, Professor Sivakumar Venkataraman, Ms Priyanka Singh, Dr Barbara Duigan, Ms Constance Mphula, Ms Senamile Sithole, and Dr Ruchith R Devaki.

Light Detection and Ranging (LiDAR) equipment in the School of Chemistry and Physics (SCP) on UKZN’s Westville campus was recently calibrated as part of an experiment to operate all three LiDARs simultaneously and interpret their performance.

The LiDARs were the fixed and portable UKZN ones as well as the Council for Scientific and Industrial Research (CSIR) National Laser Centre (NLC) mobile LiDAR.

According to Professor Sivakumar Venkataraman, the system was calibrated for the lower atmosphere up to a 30km-40km range.  Initial results show all three LiDARs are in agreement in terms of their detection of atmospheric features and locations.

The equipment, one of only two LiDAR systems in the country, assists research into remote sensing techniques and atmospheric pollution measurements conducted by the Atmospheric Research Group in the SCP, and is calibrated when necessary. The latest calibration came after refurbishment of the equipment, which was moved to the Westville campus from Howard College eight years ago.

According to Venkataraman, calibration of this nature ideally takes place at night in a clear atmosphere to avoid external light interference to the laser backscattering. The calibration was conducted over five days in early September, with result accuracy varying according to signal-to-noise ratio (SNR).

Running of the equipment is facilitated by National Research Foundation (NRF) research grants, UKZN funding and the Rental Pool Project (RPP) of the Department of Science and Technology-funded (DST) CSIR-NLC. One LiDAR system was donated to UKZN from the Université de la Réunion through a Memorandum of Understanding.

UKZN’s fixed LiDAR conducts daily observations for understanding the aerosol and cloud structure over Durban. Aerosol measurements indicate atmospheric pollution levels.

UKZN’s portable LiDAR has scanning capability and is used for studying pollution dispersion and bio-mass burning evolutions in the atmosphere (eg farmers’ burning of agricultural land for re-cultivation). The group is also involved in joint collaborative research with Algeria, which involves the building of a system for forest fire detection, with two masters and three PhD students conducting research on this subject.

The CSIR-NLC LiDAR was built under Venkataraman’s leadership and is now part of an agreement for transmitting the system to the University of Zululand (UniZulu).

In future, there could be joint observations between UKZN and UniZulu for addressing the aerosol/pollution transport between their two regions.

Christine Cuénod