ORCID Profile
0000-0001-5277-1112
Current Organisations
University of Melbourne VIC AU
,
RMIT University
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Publisher: Copernicus GmbH
Date: 23-06-2016
DOI: 10.5194/ISPRSARCHIVES-XLI-B8-673-2016
Abstract: This paper presents a methodology for the attribution and characterisation of Sclerophyll forested landscapes over large areas. First we define a set of woody vegetation data primitives (e.g. canopy cover, leaf area index (LAI), bole density, canopy height), which are then scaled-up using multiple remote sensing data sources to characterise and extract landscape woody vegetation features. The advantage of this approach is that vegetation landscape features can be described from composites of these data primitives. The proposed data primitives act as building blocks for the re-creation of past woody characterisation schemes as well as allowing for re-compilation to support present and future policy and management and decision making needs. & br& & br& Three main research sites were attributed representative of different sclerophyll woody vegetated systems (Box Iron-bark forest Mountain Ash forest Mixed Species foothills forest). High resolution hyperspectral and full waveform LiDAR data was acquired over the three research sites. At the same time, land management agencies (Victorian Department of Environment, Land Water and Planning) and researchers (RMIT, CRC for Spatial Information and CSIRO) conducted fieldwork to collect structural and functional measurements of vegetation, using traditional forest mensuration transects and plots, terrestrial lidar scanning and high temporal resolution in-situ autonomous laser (VegNet) scanners. & br& & br& Results are presented of: 1) inter-comparisons of LAI estimations made using ground based hemispherical photography, LAI 2200 PCA, CI-110 and terrestrial and airborne laser scanners 2) canopy height and vertical canopy complexity derived from airborne LiDAR validated using ground observations and, 3) time-series characterisation of land cover features. & br& & br& 1. Accuracy targets for remotely sensed LAI products to match within ground based estimates are ± 0.5 LAI or a 20% maximum (CEOS/GCOS) with new aspirational targets of 5%). In this research we conducted a total of 67 ground-based method-to-method pairwise comparisons across 11 plots in five sites, incorporating the previously mentioned LAI methods. Out of the 67 comparisons, 29 had an RMSE ≥ 0.5 LAIe. This has important implications for the validation of remotely sensed products since ground based techniques themselves exhibit LAI variations greater than internationally recommended guidelines for satellite product accuracies. & br& & br& 2. Two methods of canopy height derivation are proposed and tested over a large area (4 Million Ha). 99th percentile maximum height achieved a RMSE of 6.6%, whilst 95th percentile dominant height a RMSE = 10.3%. Vertical canopy complexity (i.e. the number of forest layers of strata) was calculated as the local maxima of vegetation density within the LiDAR canopy profile and determined using a cubic spline smoothing of Pgap. This was then validated against in-situ and LiDAR observations of canopy strata with an RMSE 0.39 canopy layers. & br& & br& 3. Preliminary results are presented of landcover characterisation using LandTrendr analysis of Landsat LEDAPS data. kNN is then used to link these features to a dense network of 800 field plots sites.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2013
Publisher: Elsevier BV
Date: 04-2009
Publisher: IEEE
Date: 07-2013
Publisher: IEEE
Date: 07-2013
Publisher: IEEE
Date: 07-2013
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier BV
Date: 15-06-2009
Publisher: Wiley
Date: 18-12-2016
Abstract: The vertical arrangement of forest canopies is a key descriptor of canopy structure, a driver of ecosystem function and indicative of forest successional stage. Yet techniques to attribute for canopy vertical structure across large and potentially heterogeneously forested areas remain elusive. This study introduces a new technique to estimate the Number of Strata ( NoS ) that comprise a canopy profile, using discrete‐return Airborne Laser Scanning (ALS) data. Vertically resolved gap probability ( P gap ) aggregated over a plot is generalized with a nonparametric cubic spline regression ( P s ). Subsequently a count of the positive zero‐crossings of second derivative of 1 − P s is used to estimate NoS . Comparison with inventory derived estimates at 24 plots across three erse study areas shows a good agreement between the two techniques (RMSE = 0·41 strata). Furthermore, this is achieved without altering model parameters, indicating the transferability of the technique across erse forest types. NoS values ranged from 0 to 4 at a further 239 plots, emphasizing the need for a method to quantify canopy vertical structure across forested landscapes. Comparison of NoS with other commonly derived ALS descriptors of canopy structure (canopy height, canopy cover and return height coefficient of determination) returned only a moderate correlation ( r 2 0·4). It is proposed the presented method provides a primary descriptor of canopy structure to complement canopy height and cover, as well as a candidate Ecological Bio ersity Variable for characterizing habitat structure.
Publisher: Elsevier BV
Date: 2021
Publisher: MDPI AG
Date: 10-06-2016
DOI: 10.3390/RS8060491
Publisher: Springer Science and Business Media LLC
Date: 31-07-2020
DOI: 10.1186/S13007-020-00646-W
Abstract: Earth Observation ‘EO’ remote sensing technology development enables original insights into vegetation function and health at ever finer temporal, spectral and spatial resolution. Research sites equipped with monitoring infrastructure such as flux towers operate at a key bridging scale between satellite platform measurements and on-the-ground leaf-level processes. This paper presents the technical details of the design and operation of a proximal observation system ‘THEMS’ that generates unattended long-term high quality thermal and hyperspectral images of a forest canopy on a short (sub-daily) timescale. The primary purpose of the system is to measure canopy temperature, spectral reflectance and radiance coincident with a highly instrumented flux tower site for benchmarking purposes. Basic system capability is demonstrated through low level data product descriptions of the high-resolution multi-angular imagery and ancillary data streams. The system has been successfully operational for more than 2 years with little to no intervention. These data can then be used to derive remotely sensed proxies of canopy and ecosystem function to study temporal forest dynamics over a wide range of wavelengths, spatial scales (in idual trees to canopy), and temporal scales (minutes to multiple years). The multi-purpose system is intended to provide unprecedented spatio-temporal ecophysiological insight and to underpin upscaling of remotely sensed dynamic ecosystem water, CO 2 , and energy exchange processes.
Publisher: MDPI AG
Date: 23-09-2015
DOI: 10.3390/RS70912563
Publisher: Elsevier BV
Date: 02-2008
Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 02-2010
Publisher: IEEE
Date: 07-2013
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 09-2011
Publisher: International Society for Horticultural Science (ISHS)
Date: 10-2012
Publisher: International Society for Horticultural Science (ISHS)
Date: 10-2012
Publisher: Springer Science and Business Media LLC
Date: 20-08-2019
Publisher: American Society for Photogrammetry and Remote Sensing
Date: 08-2015
Abstract: Pulse density, the number of laser pulses that intercept a surface per unit area, is a key consideration when acquiring an Airborne Laser Scanning (ALS) dataset. This study compares area-based vegetation structure metrics derived from multi-return ALS simulated at six pulse densities (0.05 to 4 pl m -2 ) across a range of forest types: from savannah woodlands to dense rainforests. Results suggest that accurate measurement of structure metrics (canopy height, canopy cover, and vertical canopy structure) can be achieved with a pulse density of 0.5 pl m -2 across all forest types when compared to a dataset of 10 pl m -2 . For pulse densities .5 pl m -2 , two main sources of error lead to inaccuracies in estimation: the poor identification of the ground surface and sparse vegetation cover leading to under s ling of the canopy profile. This analysis provides useful information for land managers determining capture specifications for large-area ALS acquisitions.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2009
Publisher: Elsevier BV
Date: 07-2019
Publisher: International Society for Horticultural Science (ISHS)
Date: 12-2011
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 11-2013
Publisher: Elsevier BV
Date: 03-2012
Publisher: International Society for Horticultural Science (ISHS)
Date: 12-2011
Publisher: IEEE
Date: 07-2013
Location: No location found
No related grants have been discovered for Lola Suarez.