{"id":568485,"date":"2025-11-18T16:20:22","date_gmt":"2025-11-18T19:20:22","guid":{"rendered":"https:\/\/revistapesquisa.fapesp.br\/?p=568485"},"modified":"2025-11-18T16:20:22","modified_gmt":"2025-11-18T19:20:22","slug":"radambrasil-project-celebrates-50-years","status":"publish","type":"post","link":"https:\/\/revistapesquisa.fapesp.br\/en\/radambrasil-project-celebrates-50-years\/","title":{"rendered":"RadamBrasil project celebrates 50 years"},"content":{"rendered":"

\u201cThe most daring project developed by man since Apollo,\u201d the series of space missions coordinated by NASA between 1961 and 1972. That\u2019s how Manchete<\/em> magazine described the RadamBrasil project on October 23, 1976, reflecting the pride of the time. The occasion marked the release of the first Amazon mapping results. Launched in 1975, RadamBrasil was an expansion of the earlier Radam project (short for Radar na Amaz\u00f4nia<\/em>, or Radar in the Amazon), created five years earlier. It marked the beginning of an even more ambitious undertaking: to map the entire Brazilian territory and its natural resources.<\/p>\n

As they explored vast, uncharted regions of the country, the project’s researchers had reason to feel like the pioneers of the Apollo program. \u201cWe were in a demographic void, surrounded by untouched nature,\u201d recalls geologist Pedro Edson Leal Bezerra, of the Brazilian Institute of Geography and Statistics (IBGE) in Par\u00e1. He joined the RadamBrasil project in 1977 and remained until its conclusion in 1986, when IBGE absorbed the team and the data it had collected.<\/p>\n

Bezerra participated in interpreting the radar images. A side-looking radar, manufactured by the American company Goodyear, with a spatial resolution of 16 meters, had been installed on a Caravelle aircraft\u2014a short- and medium-range jet that flew at an altitude of 12 kilometers (km) and a speed of 700 km per hour. The radar\u2019s microwave transmission and reception antenna were located in the belly of the aircraft. \u201cWe did the visual interpretations and selected the points for field verification. The Logistics Department flew over and chose a location where the camp would be set up, and we could stay there for up to three months,\u201d he recalls.<\/p>\n

\"\"

INPE <\/span>Joaquim Barbosa, from the Navy, examines a RadamBrasil map in the mid-1970s to accurately demarcate the country’s bordersINPE <\/span><\/p><\/div>\n

In the field, they collected samples of rocks, minerals, and soil. There were also teams focused on vegetation. \u201cWe measured trees and collected plant samples, which were later identified and classified by a botanist,\u201d summarizes forest engineer Joana D\u2019Arc Ferreira, from IBGE in Par\u00e1, who worked on Radam from 1974 to 1986. \u201cSince 1977, IBGE maintained an herbarium in the Roncador Ecological Reserve in the Federal District and later incorporated the RadamBrasil collection.\u201d Located in Salvador since 1980, the herbarium holds around 52,000 plant specimens, mainly from the North and Northeast.<\/p>\n

RadamBrasil brought together around 800 professionals. \u201cWe were practically hunted down in graduate programs at universities\u2014mainly the federal universities of Minas Gerais, Rio de Janeiro, and Pernambuco, as well as the University of S\u00e3o Paulo,\u201d says Jurandyr Ross, a retired geographer from USP, who worked on the project from 1977 to 1983 in the Midwest and southern Amazon.<\/p>\n

This large-scale mobilization led to many discoveries\u2014such as the 1976 identification of an estimated 3 billion tons of niobium reserves in Seis Lagos hill, Amazonas, one of the largest deposits in the world. It also highlighted areas susceptible to erosion and regions well-suited for building hydroelectric plants. \u201cWe didn\u2019t even know the exact course of the Amazon River,\u201d says geologist M\u00e1rio Ivan Cardoso de Lima, who joined Radam in 1971 and stayed until his transfer to IBGE, where he worked for another 34 years before retiring. He later compiled his experiences in the book Projeto Radam: Uma saga amaz\u00f4nica<\/em> (The Radam Project: An Amazonian Saga<\/em>) (Bel\u00e9m, Paka-Tatu, 2008).<\/p>\n

\"\"

M\u00e1rio Ivan Cardoso de Lima\u2009\/\u2009IBGE. Desbravar, Conhecer, Mapear<\/strong>. 2018<\/span>Researchers in the field arrived at radar-indicated locations either by compass, as in the Madeirinha River (AM) in 1974, or by helicopter, as in the Iriri River (PA) in 1976M\u00e1rio Ivan Cardoso de Lima\u2009\/\u2009IBGE. Desbravar, Conhecer, Mapear<\/strong>. 2018<\/span><\/p><\/div>\n

Partnership with NASA<\/strong>
\nRadam\u2019s connection to NASA goes beyond mere boastful comparison. According to Lima, the project\u2019s origins can be traced to a 1965 partnership between the US space agency and the National Commission for Space Activities (CNAE), the forerunner of today\u2019s National Institute for Space Research (INPE). \u201cNASA proposed a collaboration in the field of remote sensing, which would be used in lunar studies,\u201d he explains. This gave rise to Project Sere\u2014an acronym for Remote Sensing\u2014initially focused on the Iron Quadrangle in Minas Gerais, using data from various remote sensors, including radar. The success of that effort paved the way for its expansion to the Amazon and eventually to the entire country.<\/p>\n

\u201cSere included Radam, but it was later transferred to the Ministry of Mines and Energy,\u201d says INPE geographer Evlyn de Moraes Novo, a pioneer in satellite-based environmental monitoring. From then on, the two initiatives proceeded separately: the Satellite Remote Sensing Program, which used data from the ERTS (Earth Resources Technology Satellite, later renamed Landsat) series, and the Amazon Radar project.<\/p>\n

The use of radar for mapping the Amazon was a strategic choice, due to the region\u2019s persistent cloud cover. \u201cOptical satellite sensors operate in the visible spectrum and rely on sunlight reflected from the Earth\u2019s surface. They cannot penetrate clouds,\u201d explains INPE geographer Hermann Kux, who worked on RadamBrasil from 1977 to 1980. Radar, by contrast, emits electromagnetic waves that bounce off the surface and return to the receiver, making it effective even in cloudy conditions, both day and night, as it does not depend on sunlight.<\/p>\n

\"\"

Virlei \u00c1lvaro de Oliveira\u2009\/\u2009IBGE | Jaime Heitor Lisboa Pithan \/ IBGE. Desbravar, Conhecer, Mapear <\/strong>. 2018<\/span>Soil research team camp, set up on the banks of the Von Den Steinen River (MT) in 1979 and a landing strip used in 1977 (location unspecified<\/em>)Virlei \u00c1lvaro de Oliveira\u2009\/\u2009IBGE | Jaime Heitor Lisboa Pithan \/ IBGE. Desbravar, Conhecer, Mapear <\/strong>. 2018<\/span><\/p><\/div>\n

The mapping was organized into five thematic areas, each handled by a dedicated team: cartography, geology, terrain, soils, vegetation, and potential land use. These areas cross-referenced data to determine the most appropriate uses for each region. Understanding Brazil\u2019s natural resources was a strategic goal of the military government, which in 1970 launched the National Integration Program (PIN). Its slogans\u2014\u201cIntegrate so as not to surrender\u201d and \u201cLand without men for men without land\u201d\u2014reflected its aim: to occupy the Amazon using labor from northeastern migrants displaced by drought. The construction of the Trans-Amazonian Highway, initiated in 1970, was part of this broader objective (see<\/em> Pesquisa FAPESP issue n\u00b0 309<\/em><\/a>).<\/p>\n

Historian Leandro Cruz, who is studying the Radam project as part of his doctoral research in the history of science and health at the Oswaldo Cruz Foundation\u2019s Casa de Oswaldo Cruz (COC-FIOCRUZ), points out that another motivation was to grant companies the right to exploit the region. \u201cThe project\u2019s reports weren\u2019t publicly accessible; some were classified. But business associations could request them from the government,\u201d he notes. \u201cBy granting private companies these rights, the state offloaded some of its responsibilities in the colonization process.\u201d<\/p>\n

Interpreting the Images<\/strong>
\nLike mapping the land itself, interpreting radar images was a puzzle to be solved. \u201cThere was no defined methodology. We used to compare the images while the plane was still in flight,\u201d says Lima. The black-and-white radar images couldn\u2019t be read the same way as conventional aerial photographs. \u201cYou might see a light-colored area and assume it\u2019s sand, but that\u2019s not how the equipment works. White simply indicates high reflectance [how much energy is reflected back] which could be a mangrove swamp, for example,\u201d he explains.<\/p>\n

Different types of vegetation responded differently to the radar waves. During his PhD, completed in 1995 at the Federal University of Par\u00e1, Lima developed a methodology to correct common misinterpretations of radar images. His work helped resolve long-standing issues and resulted in two books: Introdu\u00e7\u00e3o \u00e0 Interpreta\u00e7\u00e3o Geol\u00f3gica de Radar<\/em> (Introduction to the geological Interpretation of radar; IBGE, 1995) and Geologia de Radar \u2013 Sistem\u00e1tica dos Elementos Radargr\u00e1ficos<\/em> (Geology of Radar\u2014Systematics of Radargraphic Elements; Self-published, 2017).<\/p>\n

The government had high hopes for the mapping project. In his recently published book O Brasil na era espacial<\/em> (Brazil in the space age<\/em>; Editora Viseu, 2025), geologist Raimundo Almeida Filho, who followed the project as a researcher at INPE, recalls that in March 1971, then-Minister of Mines and Energy Ant\u00f4nio Dias Leite (1920\u20132017) presented Radam to President Em\u00edlio Garrastazu M\u00e9dici (1905\u20131985), claiming it would aid in oil exploration: \u201cThe minister told the president that radar signals penetrated up to 10 meters into the ground\u2014which is false. Radar signals are indiscriminately reflected by surface features and vegetation.\u201d Even if penetration were possible, Almeida notes, it would offer little value for oil exploration.<\/p>\n

\u201cAt that time, all we had were images and hypotheses,\u201d adds Ross. The radar images, produced at a scale of 1:250,000 (where 1 centimeter equals 2.5 km), showed terrain in a rough pattern, which allowed researchers to associate certain surface features with soil types and speculate about possible mineral deposits below. But the images alone couldn\u2019t confirm anything. \u201cThere\u2019s no magic in the image,\u201d he says. \u201cFieldwork was essential to reaching accurate conclusions.\u201d<\/p>\n<\/div>

\n \n \n \n <\/picture><\/div>
\n

Fieldwork is what remote sensing specialists refer to as \u201cground truth.\u201d In the 1970s and 1980s, establishing that ground truth meant spending long hours on boats, helicopters, or small aircrafts, often in remote and difficult-to-access locations. When camps had to be set up deep in the forest, support teams would rappel from helicopters to clear a space where researchers could establish a base. As the project expanded beyond the Amazon rainforest, researchers relied more on four-wheel drive vehicles to navigate the roads of the Cerrado and Pantanal, supporting aerial surveys conducted in small aircrafts. \u201cWe used a Votec plane, which was inexpensive to maintain\u2014everything was cheap,\u201d recalls Kux, noting that the often precarious working conditions worried the families of researchers heading out into the field.<\/p>\n

Accidents were an ever-present risk. Ross remembers one particularly frightening incident over Ilha do Bananal, in Tocantins, when the helicopter he was in suddenly lost power and dropped in altitude to regain speed. Though it ended safely, not all incidents did. Over the course of the project, 55 senior and mid-level technicians, technical assistants, and military personnel lost their lives in accidents involving aircrafts, forest clearing, or illness\u2014mainly malaria. The project recorded the loss of 10 helicopters, six airplanes, and two 30-ton boats. One of the most tragic events occurred in 1980, when an airplane disappeared between Rio de Janeiro and S\u00e3o Paulo with five geographers on board.<\/p>\n

The technical reports and maps produced by the RadamBrasil project were compiled in the 38-volume Natural Resources Survey<\/em> series, available at the IBGE Library. The original radar images, printed on plain and photographic paper, were digitized starting in 2004 by the Geological Survey of Brazil (SGB) through the Radam-D project. They can be accessed at: www.sgb.gov.br\/radam-d<\/a>.<\/p>\n

This collection continues to serve as a key reference for environmental impact assessments, ecological-economic zoning, and environmental monitoring studies. In 1989, Ross\u2014then a researcher at the Geomorphology Laboratory at the University of S\u00e3o Paulo (USP)\u2014used RadamBrasil data to develop a new classification of Brazil\u2019s landforms. In the 1990s, working from radar images captured in 1976, he coordinated a project that led to the publication of the Geomorphological Map of the State of S\u00e3o Paulo<\/em> in 1998, with support from FAPESP.<\/p>\n

In 2010, geographer Ricardo Tavares Zaidan, from the Federal University of Juiz de Fora, also relied on RadamBrasil data to assess soils in the Paraibuna River basin, located in the states of Minas Gerais and Rio de Janeiro. Because the digitization of the Radam-D project had not yet been completed, he had to manually digitize the radar images. \u201cEven well-known regions of Brazil, like the Southeast, had never been systematically mapped before Radam,\u201d he notes.<\/p>\n

Evlyn Novo regrets that INPE did not participate in the project as originally intended\u2014a collaboration she believes could have enriched the results. \u201cEven so, Radam\u2019s thematic maps are still widely used today as a starting point for more detailed mapping,\u201d she says. \u201cAnd the field data remains an essential baseline for understanding what the Amazon looked like before it was occupied by cattle, before deforestation, before extreme weather, and before the fires.\u201d<\/p>\n

The story above was published with the title “Brazil on the radar<\/strong>” in issue 352 of April\/2025.<\/p>\n

Books<\/strong>
\nALMEIDA FILHO, R. O Brasil na era espacial. Maring\u00e1 (PR)<\/strong>, Editora Viseu, 2025.
\nIBGE. Desbravar, conhecer, mapear: Mem\u00f3rias do Projeto Radam \/ RadamBrasil<\/strong><\/a>. Rio de Janeiro: IBGE, 2018.
\nLIMA, M. I. C. de. Projeto Radam: uma saga amaz\u00f4nica<\/strong>. Bel\u00e9m: Paka-Tatu, 2014.
\nLIMA, M. I. C. de. Introdu\u00e7\u00e3o \u00e0 interpreta\u00e7\u00e3o radargeol\u00f3gica<\/strong>. Rio de Janeiro: IBGE, 1995.<\/p>\n

Video (documentary)<\/strong>
\nMANZON, J. Via Norte, uma realidade<\/a>. RADAM, Amaz\u00f4nia (1976) Arquivo Nacional.<\/p>\n","protected":false},"excerpt":{"rendered":"Radar mapping has uncovered natural riches, trained hundreds of specialists, and is used in research on relief, geology, soils, climate, and vegetation","protected":false},"author":131,"featured_media":568494,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[152],"tags":[213,224,200,5899,240,241],"coauthors":[440],"class_list":["post-568485","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-retrospect","tag-botany","tag-ecology","tag-environment","tag-geografia-en","tag-geology","tag-history"],"acf":[],"_links":{"self":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/568485","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/users\/131"}],"replies":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/comments?post=568485"}],"version-history":[{"count":3,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/568485\/revisions"}],"predecessor-version":[{"id":568553,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/568485\/revisions\/568553"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media\/568494"}],"wp:attachment":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media?parent=568485"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/categories?post=568485"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/tags?post=568485"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/coauthors?post=568485"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}