De La Salle University - Manila

LIDAR

SUNPHOTOMETER

The DLSU Sunphotometer System

The sunphotometer used is the Middleton SP02 (Figure 2), which composed of four silicon photodiodes (368, 500, 675 and 862 nm) with bandpass filters (10-nm bandwidth) and 5º field-of-view. It has a maximum output voltage of +4.5VDC full-scale. It operates at the rooftop of the STRC building, DLSU, Manila (14°33.967'N, 120°59.518'E) for 5 weeks using a customized sun-tracking system. Four 30-meter network cables and two 30-meter 3-line power cords were used to connect he tracking system to the DAQ system located on the LIDAR Laboratory (Rm.313).

The tracking and acquisition are done through a data acquisition card. Its 8 digital I/O lines are used to control the motors and data were acquired using its 12-bit analog inputs, which can acquire from ±0.05 to ±10.0 VDC. Ordinary network cables were used to connect to the driver box of the stepper motors and output lines of the sunphotometers.

Figure 2. The Middleton SP02 Sunphotometer