author = "Petry, Adriano and Pereira, Andr{\'e} Grahl and Souza, Jonas 
                         Rodrigues de",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universidade Federal do Rio Grande do Sul (UFRGS)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)}",
                title = "An approximate nearest neighbors search algorithm for 
                         low-dimensional grid locations",
              journal = "Earth Science Informatics",
                 year = "2017",
               volume = "10",
               number = "2",
                pages = "183--196",
                month = "June",
             keywords = "Approximate nearest neighbors, Ionosphere dynamics, Spatial 
             abstract = "We propose a new algorithm for the problem of approximate nearest 
                         neighbors (ANN) search in a regularly spaced low-dimensional grid 
                         for interpolation applications. It associates every sampled point 
                         to its nearest interpolation location, and then expands its 
                         influence to neighborhood locations in the grid, until the desired 
                         number of sampled points is achieved on every grid location. Our 
                         approach makes use of knowledge on the regular grid spacing to 
                         avoid measuring the distance between sampled points and grid 
                         locations. We compared our approach with four different 
                         state-of-the-art ANN algorithms in a large set of computational 
                         experiments. In general, our approach requires low computational 
                         effort, especially for cases with high density of sampled points, 
                         while the observed error is not significantly different. At the 
                         end, a case study is shown, where the ionosphere dynamics is 
                         predicted daily using samples from a mathematical model, which 
                         runs in parallel at 56 different longitude coordinates, providing 
                         sampled points not well distributed that follow Earths magnetic 
                         field-lines. Our approach overcomes the comparative algorithms 
                         when the ratio between the number of sampled points and grid 
                         locations is over 2849:1.",
                  doi = "10.1007/s12145-016-0282-2",
                  url = "http://dx.doi.org/10.1007/s12145-016-0282-2",
                 issn = "1865-0473 and 1865-0481",
                label = "self-archiving-INPE-MCTI-GOV-BR",
             language = "en",
           targetfile = "petry_an.pdf",
        urlaccessdate = "23 nov. 2020"