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Improving 8-dialy modis time-series to monitor forest canopy dynamics in pinus radiata plantations

conference contribution
posted on 2023-05-23, 04:01 authored by Verbesselt, J, Newnham, G, Opie, K, Sims, N, Kara BarryKara Barry, Stone, C, Caroline MohammedCaroline Mohammed, Wardlaw, T, Culvenor, D
The primary goal of this study was to evaluate and improve the quality of Moderate Resolution Imaging Spectroradiometer (MODIS) 8-daily Normalized Difference Vegetation index (NDVI) time-series to monitor changes in forest canopy of Pinus radiata plantations located at Green Hills State Forest in the Southern Highlands of New South Wales, Australia. The utility of MODIS NDVI time-series are limited by the availability of high-quality data (e.g. cloud and atmospheric scatter free). The availability of high-quality data is a critical factor in assessing forest dynamics or phenological parameters such as the onset of crown flushing. The MODIS 250 m spatial resolution NDVI 8-daily (MOD09Q1) and 16-daily time-series (MOD13Q1) from 2000 to 2006 were employed in this study. Firstly, it was shown that the vegetation usefulness index provided with the MOD13Q1 data is dominated by a sun zenith angle threshold set at 60°. The flagging of data errors was optimized by using information on aerosol quantity, atmosphere adjacency correction, mixed cloud, shadow, and satellite viewing angle. Secondly, major data errors were detected in the 8-daily time-series by using the 16-daily time-series. This approach increases the usefulness of the 8- daily time-series which offers a higher temporal resolution and a smaller influence by the compositing technique than the MOD13Q1 product. Thirdly, the Fast Fourier Transform and to a lesser extent the 'running median' approach were influenced by these major data errors. This study has shown that it is crucial to evaluate properties of remote sensing time-series before studying temporal forest growth and health dynamics.

Funding

Australian Research Council

Forestry Tasmania

Forests and Forest Industry Council of Tasmania

Gunns Limited

WA Plantation Resources

History

Publication title

Proceedings of Forest Sat 2007 Conference & Scientific Workshop

Department/School

Tasmanian Institute of Agriculture (TIA)

Publisher

Forest Sat 2007

Place of publication

Montpellier, France

Event title

Forest Sat 2007 Conference

Event Venue

Montpellier, France

Date of Event (Start Date)

2007-11-05

Date of Event (End Date)

2007-11-07

Rights statement

Copyright 2007 the Author

Repository Status

  • Restricted

Socio-economic Objectives

Hardwood plantations

Usage metrics

    University Of Tasmania

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