Figure 5.

Observing the effects of cloud cover, sunrise, sunset, lights-ON, lights-OFF and buildings around the data collection site on the ambient light in a built environment for two continuous days (48 h). The solid-orange bars (❚) depict the amount of ambient light sensed by the color sensor in Lumen per square meter (LUX). The solid-blue circles (●) depict the local cloud cover in percentage of local sky covered by clouds. The sunrise and sunset times are indicated with the rising and setting sun symbols, respectively, using the upward and downward arrows. The yellow and black bulbs specify the lights-ON and lights-OFF times, respectively. The skyscraper symbol indicates the time when the Sun goes behind a skyscraper and causes a shadow onto the location where ambient light was being tracked. Data upload is depicted by binary values and a cloud node.