@InProceedings{CāmaraFreiCasa:1995:FiObAl,
               author = "C{\^a}mara, Gilberto and Freitas, Ubirajara Moura de and 
                         Casanova, M. A.",
                title = "Fields and objetcts algebra for GIS operations",
            booktitle = "Anais...",
                 year = "1995",
                pages = "407--423",
         organization = "Simp{\'o}sio Brasileiro de Geoprocessamento, 3.",
             keywords = "GEOPROCESSAMENTO, {\'a}lgebra, Sistemas de Informa{\c{c}}{\~a}o 
                         Geogr{\'a}fica (sig), linguagem (computador), legal, spring, 
                         Sistema de Processamento de Imagens Georreferenciadas (SPRING), 
                         languagem programminggeographical informatiom systems.",
             abstract = "Este trabalho discute o problema da defini{\c{c}}{\~a}o formal 
                         das opera{\c{c}}{\~o}es em Sistemas de informa{\c{c}}{\~a}o 
                         geogr{\'a}fica. Os dados geogr{\'a}ficos s{\~a}o divididos em 
                         duas classes: geo-objetos e geo-campos, o que reflete a natureza 
                         dual (discreto-continuo) das representa{\c{c}}{\~o}es da 
                         realidade geogr{\'a}fica. Estudam-se as opera{\c{c}}{\~o}es 
                         sobre campos, geo-objetos e as transforma{\c{c}}{\~o}es entre 
                         geo-campos e geo-objetos. A analise deste trabalho serve de base 
                         para LEGAL, uma linguagem espacial utilizada no sistema SPRING, 
                         desenvolvido pelo INPE com apoio da IBM Brasil e da EMBRAPA. 
                         ABSTRACT: This paper addresses the problem of formal definition of 
                         the operations on geographical information systems (GIS). 
                         Geographical data is divided in two main classes: geo-objects and 
                         geofields, which portray discrete and continuous representations 
                         of reality. We study the operations over geo-fields, geo-objects, 
                         and the transformations between geo-fields and geo-objects. This 
                         analysis has been used as the basis for LEGAL, a general spatial 
                         language, which is used in the SPRING GIS, developed by INPE, with 
                         support fiom IBM Brasil and EMBRAPA.",
  conference-location = "Sao Paulo, BR",
      conference-year = "12-14 jul. 1995",
           copyholder = "SID/SCD",
                label = "8940",
             language = "pt",
           targetfile = "1995_camara2.pdf",
        urlaccessdate = "05 maio 2024"
}