Design and Implementation of Low Cost IoT Sensor System for Urban Heat Island Observation

Urban Heat Island (UHI) is a phenomenon that deserves some considerations because of the effect on humans living in a certain environment. It is characterized by higher temperatures in urban than in rural area. Generally, there are 2 typical identification methods for UHI: indirect measurement such as remote sensing, and direct measurement such as fixed stations and mobile traverses. Remote sensing is a common approach, especially in Indonesia. However, fixed stations are difficult to establish due to economic factors. A system that collects data from various point of observation to figure out the surrounding area, similar to and an alternative of fixed station, can be beneficial for Indonesia. Therefore, we propose a UHI monitoring system based on Internet of Things (IoT). In the design of low-cost IoT sensor node, sensor boards are encapsulated in enclosure and sensor point tip is covered by custom Stevenson screen to reduce solar radiation. Temperature and humidity data are collected every minute and sent through the internet using MQTT protocol every hour. Gathered and stored data are subscribed automatically using the Amazon Web Service, and an API is provided to access the data. Based on the implementation, we analyze the data and showed that there are distinctions in temperature and humidity between roadway and residential area. The result also showed that this system can retrieve data from a low-cost IoT sensor node that can be collected, stored, and accessed by a cloud service via API.