URBAN VEGETATION MAPPING BASED ON THE HJ-1 NDVI RECONSTRCTION
- 1Department of Geographic Information Science, Hohai University, Nanjing, 211000, China
- 2Geography Graduate Group, University of California, Davis, 95616, USA
- 3Department of Civil Engineering, Monash University, 3800, Australia
- 4Department of Geographic Information Science, Nanjing University, Nanjing, 210023, China
Keywords: HJ-1 NDVI, Urban vegetation mapping, Nanjing city, Filtering algorithm
Abstract. HJ-1A/B NDVI (HJ NDVI) time-series data possess relatively high spatio-temporal resolution which is significant for the research on urban areas. However, its application is hindered by noise resulting from the restrictions of imaging quality and limits of the satellite platform. The NDVI noise reduction is necessary. Some noise-reduction techniques including the asymmetric Gaussian filter (AG), the double logistic filter (DL), the Savitzky-Golay (S-G) filter and the harmonic analysis (Hants) of NDVI time-series have been used to carry out the NDVI time series reconstruction, and based on the comparison results of different filter, S-G filter is the optimal in the application on urban areas. Finally,urban vegetation mapping is carried out based on the new HJ NDVI.