Brazil began investing in training professionals and developing infrastructure to enable the application of remote sensing techniques at the end of the 1960s, with the implementation of the Remote Sensing Project at the Institute for Space Research. In the early 70s, all activities focused on receiving and using MSS orbital images from Landsat series satellites. However, the knowledge available at that time was restricted to enabling the identification of specific features existing on the terrestrial surface, which, in turn, enabled the elaboration of varied thematic maps.
In the mid-1980s, with the launch of the Thematic Mapper (TM) sensor aboard the Landsat 4 satellite and later on the Landsat 5, the finer spatial resolution and greater number of spectral bands explored by this sensor in relation to its predecessor MSS , opened up new possibilities for the application of remote sensing techniques, including not only thematic mappings but also studies aimed at quantifying biophysical parameters (for example, forest biomass) through the use of radiometric data derived from the generated images.
Regardless of the academic nature of the activities linked to the use of remote sensing techniques (many of the works were the result of master’s dissertations or doctoral theses), at this time, the first companies focused on the application of this technology to meet market demands also began to appear. These companies started to sell services, exploiting the knowledge that was being acquired by research institutions such as the National Institute for Space Research (INPE). They also began to develop their own solutions to problems that emerged as a result of providing increasingly sophisticated and specific services. Thus, the country has innumerable possibilities for the application of remote sensing techniques, which have even been undergoing conceptual changes.
The works that previously focused on the use of orbital images or aerial photographs aiming only at the mapping of a certain feature or classes of land surface coverage, now include the quantification of geophysical and biophysical parameters, which required a deepening of the knowledge of the principles on which remote sensing techniques are based. This knowledge is increasingly necessary due to the new possibilities of using data from sensors with increasingly finer spatial resolutions and which are enabling the realization of services considered impossible to be made possible through the use of sensors previously available as the MSS and TM. This is the case of the sensor placed on board the IKONOS satellite, which aims to generate images that enable the identification of objects with dimensions around 4 to 5 meters, in spectral ranges ranging from visible to near infrared.
This opens up new possibilities in the application of data generated from remote sensing techniques, creating alternatives for the development and application of other techniques, now called geoprocessing techniques or simply geotechnologies. Remote sensing now moves to another stage in its history in the country.
References:
Campbell, James B., and Randolph H. Wynne. Introduction to remote sensing. Guilford Press, 2011.
Colwell, Robert N. “Manual of remote sensing.” (1985).
Lo, Chor Pang. “Applied remote sensing.” (1986): 60-60.
Cracknell, Arthur P. Introduction to remote sensing. CRC press, 2007.
