Mapping deciduous forests by using time series of filtered MODIS NDVI and neural networks

• Main Author: Oliveira, Thomaz Chaves de Andrade
• Publication Date: 2015
• Other Authors: Carvalho, Luis Marcelo Tavares de, Oliveira, Luciano Teixeira de, Martinhago, Adriana Zanella, Acerbi Júnior, Fausto Weimar, Lima, Mariana Peres de
• Format: Article
• Language: eng
• Source: Repositório Institucional da UFLA
• Download full: http://www.cerne.ufla.br/site/index.php/CERNE/article/view/673; http://repositorio.ufla.br/jspui/handle/1/14002
• topic: Remote sensing; Signal processing; Time series; Wavelets analysis; Fourier; Sensoriamento remoto; Processamento de sinais; Séries temporais; Análise wavelet

Multi-temporal images are now of standard use in remote sensing of vegetation during monitoring and classification.Temporal vegetation signatures (i. e., vegetation indices as functions of time) generated, poses many challenges, primarily due tosignal to noise-related issues. This study investigates which methods generate the most appropriate smoothed curves of vegetationsignatures on MODIS NDVI time series. The filtering techniques compared were the HANTS algorithm which is based on Fourieranalyses and Wavelet temporal algorithm which uses the wavelet analysis to generate the smoothed curves. The study was conductedin four different regions of the Minas Gerais State. The smoothed data were used as input data vectors for vegetation classificationby means of artificial neural networks for comparison purpose. A comparison of the results was ultimately discussed in this workshowing encouraging results and similarity between the two filtering techniques used.