In the past, navigators, cartographers, scientists and many people observed the movements of the Sun and stars to guide themselves and make decisions. Today, the sky looks at us and provides us with information such as: location, satellite images and telecommunications. Based on this data, and with the advancement of technology in recent decades, our lives have transformed and, today, we are able to obtain information almost in real time from anywhere on the globe.
The context of wars ended up boosting the advancement of some technologies, such as, for example, launching nuclear missiles and space rockets. With regard to space technology, the leap was greater. After the Second World War, the first artificial satellite, Sputnik 1, and the first man into space were sent by the Soviet space program, which began the space race in which the North Americans and Soviets competed for technological hegemony linked to the exploration of space. space. Another important milestone was the launch of GPS signal satellites. Initially exclusively for military use (to determine the exact position of the target to be hit by a missile), today GPS systems are present in cell phones, cars and even watches!
“The Earth is blue,” said Yuri Gagarin, the first man sent into space, in 1961. A year earlier, the first weather satellite was successfully launched into space by NASA. TIROS 1 (Television Infrared Observation Satellite) obtained the first image of the Earth seen from space, but in the image it appeared in shades of gray. It was clear that there was still a lot to evolve. It didn't matter just to have a colorful and beautiful image. The TIROS program presented innovative technology for the time and tested various solutions for spacecraft such as instruments, data and operational parameters. The main objective was to improve the acquisition of information about the Earth for eventual decision-making, such as: "Should we evacuate the coast because of a particular hurricane?".
The successful launch of the TIROS program (1960-1978) provided the first images and data collected from space to make weather forecasts more accurate. The success of TIROS, with many instruments and orbital configurations, led to the development of other more sophisticated meteorological observation programs, such as: NOAA (from 1979 to the present day), MetOp (from 2006 to the present day) and GOES (from 1975 to the present day) XNUMX to present day). Weather and climate forecasting centers around the world use information from weather satellites about the Earth's atmosphere and surface to improve weather forecasting and climate research.
The Center for Meteorological and Climate Research Applied to Agriculture (Cepagri) also makes up this list, with a long history of receiving data and images from meteorological satellites, starting just two years after its creation, in 1983. The first system of reception and analysis of images from meteorological satellites acquired by Cepagri was the UAI-R (Image Analysis Unit – Remote), in partnership with the National Institute for Space Research (Inpe), which was active for twelve years. In addition to being used for weather forecasting, these images have been used in research into agriculture and the environment. From the great demand for the use of these satellite images, one of the Center's main areas of activity arose, the processing of remote sensing images.
In 1994, the second system for receiving and processing images from meteorological satellites of the AVHRR/NOAA (Advanced Very-High Resolution Radiometer/National Oceanic and Atmospheric Administration) series was acquired. In 2004, the system was updated with the acquisition of more modern equipment, allowing it to capture and process images from satellites in the AVHRR/MetOp (Meteorological Operational Satellite Programme) series, which operated until 2018. The images received since April 1995 are stored in the database of the Center, constituting one of the main image banks of the AVHRR/MetOp/NOAA series satellites in Brazil and abroad.
Cepagri currently has the most modern meteorological satellite image reception system in the world, GOES-16, from the new generation GOES-R (Geostationary Operational Environmental Satellites). Unicamp is the first Brazilian public university to receive images from this satellite, placing the Center in a prominent position nationally and worldwide. The images have high temporal and spatial resolution. Its temporal resolution is five minutes, when extreme events occur, and ten minutes, for image acquisition of the entire globe. In the previous generation of satellites (GOES-13), these intervals were of one hour or at least 30 minutes. Regarding spatial resolution, the pixel reaches 500 meters and one kilometer in resolution, four times more refined than the previous generation of satellites (GOES-13).
Today, the biggest challenge is maintaining, organizing and making Cepagri's database of meteorological satellite images available free of charge. In addition to the long time series of images, spanning more than 30 years, the Center receives more than 2.300 images daily, occupying 160 GB of database storage. In a year, there are approximately 840 thousand images and 60 TB of data to store, in addition to the products that are generated by these images, reaching 100 TB of data annually. The products from GOES-16 provide a series of benefits to society, such as more accurate weather forecasting and better subsidies for researchers to carry out more refined monitoring and studies aimed at both agriculture (soil, plantation and harvest forecasting), and for the environment (forests and water bodies). This information can also contribute to triggering actions aimed at reducing food, material, social and economic losses and damages.
From the use of aerial photographs to satellite images, there has been a major advance, not only in the quality of information, but also in the way data is made available. Access to satellite images, both meteorological and environmental, has become popular. It is possible to obtain information on the Earth's surface in real time, free or at low cost. The use of this technology is no longer just for military purposes. Over time, it has been widely used for scientific research, government planning actions, weather forecasts and decision making. It is up to each of us to use the available information in the best way possible, to improve our quality of life and preserve planet Earth.
*Renata Ribeiro do Valle Gonçalves has a degree in Cartographic Engineering, a master's degree and a doctorate in Agricultural Engineering from Unicamp. His area of expertise is Remote Sensing (Time Series of Satellite Images). She has been an employee of Cepagri since 2013, having been director of the Center from August 2014 to August 2020.
This text is an opinion article and does not necessarily reflect the opinion of Unicamp.
