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Time - Frequency Analysis of Narrow Bipolar Pulses observed in Sri Lanka

L Gunasekara; A. Vayanganie; S Jayalal; M Fernando; U Sonnadara; V Cooray (ICLP, 2016)

Narrow Bipolar Pulses (NBP) of a single thunderstorm from a coastal location in Sri Lanka were subjected to S-transformation in order to study their timefrequency information. This study is an extension to a similar study ...

Fractal Analysis of Long Laboratory Sparks of high Speed Video Recordings

A Vayanganie; L Gunasekera; M Fernando; U Sonnadara; V Cooray; M Rahman; P Hettiarachchi; O Diaz (ICLP, 2016)

Variation of fractal dimension of long laboratory sparks were studied using high speed video recordings and still images. Four sparks were selected for the study, including both positive and negative polarities in ...

Regular Pulse Trains in Chaotic pulse Bursts

R Abeywardhana; M Fernando; U Sonnadara; V Cooray (ICLP, 2016)

Electric field pulse bursts generated by lightning flashes are considered as sources of high radio frequencies. In this study, an analysis of pulse bursts in electric field records of 30 negative cloud to ground lightning ...

Collision Detection through Optical Flow

Sandaruwan, S.; Illeperuma, G.; Sonnadara, D.U.J. (IPSL, 2016)

In this paper, an analysis of collision detection via optical flow is presented. The main objective of the work is to detect and initiate a warning signal when there is a non-moving object or a moving object (such as a ...

Spatial and temporal variations of thunderstorm activities over Sri Lanka

Sonnadara, D.U.J. (2016)

Multifractal behavior of wind speed and wind direction

Weerasinghe, R.M.; Pannila, A.S.; Jayananada, M.K.; Sonnadara, D.U.J. (2016)

An assessment of CSIRO Conformal Cubic Atmospheric Model simulations over Sri Lanka

Thevakaran, A.; McGregor, J.L.; Katzfey, J.; Hoffmann, P.; Suppiah, R.; Sonnadara, D.U.J. (2016)

Characteristics of Narrow Bipolar Pulses observed from lightning in Sri Lanka

Gunasekara, T.; Fernando, M.; Sonnadara, D.U.J.; Cooray, V. (2016)

Century Scale Climate Change in the Central Highlands of Sri Lanka

De Silva, J.; Sonnadara, D.U.J. (2016)

ABSTRACT An analysis of century scale climate trends in the central highlands of Sri Lanka is presented. Monthly rainfall and temperature records of the period 1869 – 2006 from five climatological stations were analyzed. ...

Evaluation of best management practices with greenhouse gas benefits for salt-affected paddy soils in South Asia

Lokupitiya, E.Y.K.; Agrawal, Madhoolika; Ahamed, Tofyel; Mustafa, Naveed; Ahmed, Bashir; Vathani, Archana; Opatha, Kaushala; Jaiswal, Bhavna; Singh, Suruchi; Seneviratne, Gamini; Sirisena, DN; Paustian, Keith (2020)

Anthropogenic climate change has caused increased soil salinity in South Asia due to saltwater intrusion caused by sea level rise, input of fertilizers with high salt index, and irrigation malpractices, etc. Salinity has ...

Deriving Comprehensive County-Level Crop Yield and Area Data for U.S. Cropland

Lokupitiya, E.Y.K.; Breidt, F. Jay; Lokupitiya, Ravindra; Williams, Steve; Paustian, Keith (2007)

Ground-based data on crop production in the USA is provided through surveys conducted by the National Agricultural Statistics Service (NASS) and the Census of Agriculture (AgCensus). Statistics from these surveys are ...

Simulation of optical flow and fuzzy based obstacle avoidance system for mobile robots

Illeperuma, D.G.; Sonnadara, D.U.J. (2015)

Honey bees use optical flow to avoid obstacles effectively. In this research work similar methodology was tested on a simulated mobile robot. Simulation framework was based on VRML and Simulink in a 3D world. Optical ...

Evaluation of Downscaled Climate Projections over Sri Lanka

Thevakaran, A.; McGregor, J.L.; Katzfey, J.; Thatcher, M.; Suppiah, R.; Sonnadara, D.U.J. (IPSL, 2015)

This study presents an assessment of the Conformal Cubic Atmospheric Model downscaled climate projections at 8 km spatial resolution which are forced by sea surface temperature and sea ice concentration of three global ...

Automated Rain Sampler for Real time pH and Conductivity Measurements

Weerasinghe, R.; Pannila, A.S.; Jayananda, M.K.; Sonnadara, D.U.J. (IPSL, 2015)

To monitor the acidity of rain water in real time, a rain water sampling system was developed. The rain sampler detects the initial rain after a dry spell and collects a water sample. Before performing the measurements, ...

The onset, retreat and the length of growing season in the north-eastern region of Sri Lanka

Sonnadara, D.U.J. (John Wiley & Sons, Ltd., 2015)

Use of AVHRR NDVI time series and ground-based surveys for estimating county-level crop biomass

Lokupitiya, E.Y.K.; Lefsky, M.; Paustian, K. (Taylor & Francis Group, 2010)

Crop biomass and residue production are major components of cropland carbon dynamics that can be estimated using yield data from ground-based surveys. In the USA, surveyed yield data are available at county level and ...

Climate-Smart Initiatives in Sri Lankan Agriculture Sector: Experience and Perspectives in Solar Powered Water Pumping for Sustainable Crop Production

Rotawewa, Bandara; Lokupitiya, E.Y.K. (Asian Online Journals (www.ajouronline.com), 2020)

The availability of low cost and long-lasting water pumping technology is a dream of every farmer. In Sri Lanka, fuel or electricity-powered water pumps are used to irrigate thousands of hectares of field crops, Vegetables, ...

Traffic composition and variability of road traffic noise levels in the vicinity of Colombo, Sri Lanka

Kalansuriya, C.M.; Pannila, A.S.; Sonnadara, D.U.J. (NSF, 2015)

Abstract: A study was conducted to determine the contribution of different types of vehicles to road traffic noise levels. Measurements were carried out on three different categories of roads at six separate locations, ...

Interannual variability of precipitation in Sri Lanka

Jayawardene, H.; Jayewardene, D.R.; Sonnadara, D.U.J. (2015)

Abstract: Two different spectral analysis methods, the multitaper method (MTM) and the maximum entropy method (MEM) were applied to investigate the presence of low-frequency periodicities in precipitation records of ...

Fractal dimension of long electrical discharges

Amarasinghe, D.; Sonnadara, D.U.J.; Berg, M.; Cooray, V. (Elsevier, 2015)

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