A Development of Microcontroller Based LED Sunphotometer with Sun-tracking System for Measuring Aerosol Optical Depth

Aerosol Optical Properties is important for earth's surface. Aerosols can affect the earth's surface depending on its chemical and physical properties. These can be by scattering and absorption process. The goal of this research is to develop a simple and portable system that can measure aerosol optical properties in the atmosphere. This research will be used for air pollution monitoring in the Philippines. The people involved in air pollution research may use the data gathered from this device especially the aerosol optical properties. The research focuses on developing a five-channel LED-based sunphotometer to measure direct sunlight at specific wavelength bands. Also, a microcontroller-based data acquisition will be developed for the sunphotometer. There will be a tracking system that can point the sunphotometer directly to the sun. With the use of Langley method, the researchers will be able to calibrate the LED sunphotometer. Correlation of data was done with the data of sunphotometer with ground-based systems. The aerosol optical depth data is collected using the device and other surface-based sunphotometers. The researchers got 0.75 which means high correlation. The aerosol optical properties using LED channel sunphotometer is comparable to the commercially available sunphotometer.