TIMESAT - a program for analyzing time-series of satellite sensor data

Summary, in English

Three different least-squares methods for processing time-series of satellite sensor data are presented. The first method uses local polynomial functions and can be classified as an adaptive Savitzky-Golay filter. The other two methods are more clear cut least-squares methods, where data are fit to a basis of harmonic functions and asymmetric Gaussian functions, respectively. The methods incorporate qualitative information on cloud contamination from ancillary datasets. The resulting smooth curves are used for extracting seasonal parameters related to the growing seasons. The methods are implemented in a computer program, TIMESAT, and applied to NASA/NOAA Pathfinder AVHRR Land Normalized Difference Vegetation Index data over Africa, giving spatially coherent images of seasonal parameters such as beginnings and ends of growing seasons, seasonally integrated NDVI and seasonal amplitudes. Based on general principles, the TIMESAT program can be used also for other types of satellite-derived time-series data.

• Författare: Per Jönsson; Lars Eklundh
• Avdelning/ar: Atomfysik; Institutionen för naturgeografi och ekosystemvetenskap
• Publiceringsår: 2004
• Språk: Engelska
• Sidor: 833-845
• Publikation/Tidskrift/Serie: Computers & Geosciences
• Volym: 30
• Issue: 8
• Fulltext: - 469 kB; Download statistics
• Länkar: http://dx.doi.org/10.1016/j.cageo.2004.05.006
• Dokumenttyp: Artikel i tidskrift
• Förlag: Pergamon Press Ltd.
• Ämne: Atom and Molecular Physics and Optics; Physical Geography
• Nyckelord: NOAA; TIMESAT; phenology; seasonality; function fitting; data smoothing; CLAVR; NDVI; AVHRR
• Aktiv: Published
• Projekt: TIMESAT - software to analyze time-series of satellite sensor data
• ISBN/ISSN/Övrigt: ISSN: 1873-7803