Geography Reference
In-Depth Information
It is interesting that we are quickly reaching the point of discussing ethical and legal issues,
such as the new limitations for the progress of orbital imaging at still greater detail levels,
which reflect problems such as invasion of privacy and national security.
In the case of Brazil, as in any other country, there is a choice of sensors which for several
reasons become interesting, and which naturally prevail over the remaining, responding for
the great majority of applications. In this investigation, we seek to focus those cases, trying
to contribute for greater clarification regarding the potential and limitations of each option,
limiting ourselves in this first approach to geometric issues. The 10 sensors presented here
constitute the first phase of our investigation line, which will have continuity in the
assessment of new sensors, such as Rapideye, Terrasar-X and Worldview 2. Another effort
that is being developed, but which is still in an initial phase, is the diligent assessment of the
potential of those products for extraction of the cartographic elements, a term which we call
interpretability, whose scale of attendance tends to be less than the one defined by
geometry.
The organization of the assessments carried out in three classes of scales was considered
important for a better orientation of applications by the users. The limits adopted, using as
important threshold the 1:25,000 scale, represent mapping challenges in Brazil, whose
scarcity at this level of detail is immense. Considering the country's growth, the demand for
reliable georeferenced information has increased a lot, which may translate a greater
concern for its attendance by specialized institutions of the sector and, on the other hand,
unfortunately, the explosion of individualized, and standalone solutions, in most cases,
without the necessary control and knowledge. It is sought therefore, to contribute for the
awareness of the community in general regarding those issues.
Author details
Carla Bernadete Madureira Cruz and Rafael Silva de Barros
Departamento de Geografia, Instituto de Geociências, Universidade Federal do Rio de Janeiro - UFRJ,
Rua Athos da Silveira Ramos, CCMN, Cidade Universitária, CEP 21941-590 - Rio de Janeiro, Brasil
Acknowledgement
Our thanks to the Research Center Leopoldo Americo Miguez de Mello (CENPES),
Petrobras, which supported this research by providing the resources necessary for its
preparation.
9. References
Journal
[8] TOUTIN, T. & CHENG, P. (2002) Comparision of Automated Digital Elevation Model
Extraction Results Using Along-Track ASTER and Across-Track SPOT Stereo Images.
SPIE Journal, Optical Engeneering, 41 (9), p. 2102-2106.
