Through the capture of nighttime aerial images with a drone provided by the Cielos de Chile Foundation, a team of university researchers identified points of light pollution in the city of Antofagasta.
A team from the Astronomy Center of the University of Antofagasta, composed of Eduardo Unda-Sanzana, Christian Adam, Nicolás Mac-Lean, and Juan Pablo Colque, presented the first light map of the city. The study shows how the city is illuminated and presents a methodology that can be replicated in other municipalities in the country.
The map was created based on 416 individual shots taken along the coastal edge of Antofagasta, using a drone provided by the Cielos de Chile Foundation. According to Eduardo Unda-Sanzana, director of the UA Astronomy Center, the project’s goal was to generate a tool to optimize the inspections of polluting light sources.
According to the expert, drone technology proved to be more efficient than other methodologies, making the work less laborious and more precise. “We wanted to do something that, in a relatively short time frame, would allow us to generate a representation of the entire city and that this could, with the necessary resources, start to be repeated more systematically in the future and you could see how the situation evolves,” explained Eduardo.
Three key findings: new polluting sources, greater presence of cold lights along the coast, and differentiated lighting by area
The study presents three key findings regarding light pollution and the use of outdoor lighting in the municipality. One of them is that a significant number of paddle courts and sports fields of educational establishments use lighting with a greater presence of blue light that remains on during the night. As the authors note in the study, these spaces “function as large polluting reflectors” of the city.
On the other hand, a surprising element was the significant presence of cold lights in the coastal area, raising the alarm about the negative effects this type of lighting has on marine ecosystems, especially on coastal birds. For Eduardo, this could be related to the use of more recreational lighting on the waterfront and also by some industrial installations.
Additionally, they observed that the color of the lights in the city is not homogeneous and the colder lights are more concentrated in the north of the municipality. In light of this finding, the research mentions the existence of “light segregation,” a concept from the North American academy, where lower social class neighborhoods have lighting with a higher index of light pollution compared to the upper neighborhoods of a city.
“We wondered if something similar could be happening here in Chile and, in particular, in our city. And, indeed, we quickly began to see that the type of lighting is significantly different,” pointed out Eduardo. He adds that this could be explained by the development of new works that use colder lights to offer a greater sense of security, public space projects that also use cold lights, and that these lights tend to be more economical.
A new tool for the enforcement of the new lighting regulations
Eduardo Unda-Sanzana points out that the work done with the Astronomy Center presents the initial guidelines to replicate this project in other municipalities in Chile. Additionally, they highlight the positive effects of preferring to use technology like drones to more effectively monitor the outdoor lighting of a city.
Months before the New Lighting Standard comes into effect in October 2024, this experiment, Eduardo assures, also serves as input for inspectors, who will know what type of establishments and in which areas to pay more attention.
“It is about having a methodology that allows authorities to quickly identify which are the focal points where it is advisable to pay more attention, either because it coincides with recurring complaints or to open lines of dialogue with those responsible for some main sources of light pollution,” he concluded.
