The advantage of the data that emerges from satellite images is that they can cover areas where conducting a conventional survey is difficult due to factors such as physical or social hazard. In addition, these photos can guarantee constant monitoring of small or inaccessible localities or areas in less developed countries, something that periodic surveys do not allow, according to Andrea Coppola, one of the authors of the World Bank study 'Estimation of poverty local using satellite images. '
In order to demonstrate their hypothesis, the researchers chose Guatemala and studied information regarding 338 municipalities provided by the National Institute of Statistics (INE). In their study, the scientists analyzed the links between existing data on rural and urban poverty obtained through censuses and household surveys and nighttime lighting (this information was provided by the US National Oceanic and Atmospheric Administration).
The researchers found that information on luminosity can go a long way in measuring rural poverty. However, it was not very useful in measuring urban poverty. As an example of the change in the intensity of night light, the satellite images of Guatemala are presented, where on the left side the black areas indicate night lighting in 2001 and on the right the same factor in 2008.
In the next photo, newer or more intense lights are indicated in orange, and less intense lights are shown in blue.
The study led the researchers to conclude that it is currently impossible to completely replace traditional satellite photo surveys when it comes to measuring poverty. However, images from space play an important role in the improvement and precision of the data obtained in a conventional way.