Electromagnetic signal strength intensity maps of gsm base stations in the Istanbul Technical University main campus area

Electromagnetic signals are described as waves with particular frequencies. The electromagnetic signals may be generated by natural causes as well as by man-made wireless communication systems. The level of the electromagnetic signal exposure increases as the technological developments require the higher usage of electronic devices as well as Wireless Fidelity (WiFi) and Global System for Mobile (GSM) services. Especially in recent years, the transition to 2nd Genetration (2G), 3rd Generation (3G) mobile technologies and the investments on the new generation 4th Generation (4G) and 4.5th Generation (4.5G) technologies cause rapid developments in Turkey in terms of GSM services. The rapid development in the field of the GSM services and the consequent electromagnetic field (EMF) exposure to the human body generated the debate on the potential dangers of the services on the human health. A lot of research studies focused on the subject however there are no certain evidences about the consequences of the EMF exposure. On the other hand, there are still views suggesting such exposure might affect the human body in different ways. To reduce such effects to minimum, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) declared boundary values for the base stations, which are the main source of the electromagnetic fields, and those values are accepted by many European countries as well as some other countries all over the World in 1998. In this study, within the boundaries of the Istanbul Technical University (ITU), using pre-specified 29 stations, the power densities of the electromagnetic signals having frequencies of 900 and 1800 MHz are measured in V/m unit by using the Spectra HF-6065 device. The results are geographically analyzed and the measurements taken for each frequency are shown on a heat map. Geographic Information Systems (GIS) and spatial interpolation techniques are used for performing electromagnetic field intensity maps. 3 different spatial interpolation methods are used for creating maps and results are compared with each other. Considering the minimum mean square error, Radial Basis and Empirical Bayesian Krigging methods are selected. In addition to electromagnetic field intensity data, social media location data are used as a supportive data for analysing mobile and 3G technologies. Within the study area, location data from Twitter are collected during one month with using Twitter Application Programming Interface (API). After collecting the location data, a heatmap has been created for visualizing mobile density. In the final step of the study, EMF intensity results are compared with mobile density map, which is created by using social media location data and the relation between the two data sets are composed. Based on the results, a methodology has been suggested for identifying spatial relation between mobile density and EMF intensity values. At the same time, it is introduced that the social media location data can be used for prediction of EMF intensity values. Furthermore, the EMF intensity values are compared with the ICNIRP standards. Results showed that the exposure levels of the electromagnetic field intensities are within the limits of the ICNIRP. However, since the EMF intensity level for the human health is not known, it is not possible to confirm if the measured levels are safe for human health. The aim of this study is to create electromagnetic field intensity maps of ITU and find potential risky areas against threads in the future.