David Jupp

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Retired scientist involved in applications of remote sensing and image processing since 1978. Original background of applied mathematics, physics and geophysics. Since retirement have had further interests in the use of 3S technology for investigating China's ancient Plank Roads and in old maps.
Address: Canberra, Australian Capital Territory, Australia

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A Dual Wavelength Echidna® Lidar (DWEL) for Forest Structure Retrieval

AGUFM, Dec 1, 2012

Using airborne and ground-based ranging lidar to measure canopy structure in Australian forests

Canadian Journal of Remote Sensing, Oct 1, 2003

Airborne and ground-based lidars are useful tools to probe the structure of forest canopies. Such... more Airborne and ground-based lidars are useful tools to probe the structure of forest canopies. Such information is not readily available from other remote sensing methods but is essential for modern forest inventory in which growth models and ecological assessment are becoming increasingly important. This study was undertaken to investigate the capacity of current airborne and ground-based ranging systems to provide data from which useful forest inventory parameters can be derived. Additional data collected included standard forest inventory, hemispherical photography, and optical point-quadrat sampling. Four contrasting study sites were established within an existing study area in the Bago and Maragle State Forests, New South Wales, Australia. A simple and standard set of models was fitted to the data to establish consistency between methods and current practice. Methods to reduce the bias induced by interaction of the size of the airborne laser scanner (ALS) footprint and thresholding used in ranging systems are demonstrated by the use of first and last returns and the intensity of the returns. A measure analogous to predominant height was calculated from an average of a number of the highest ALS returns within an area. This estimate agreed with field measured predominant heights within the uncertainty of the measurements. Data from a ground-based scanning rangefinder system were used to model leaf area index (LAI). These LAI estimates coincided with those from hemispherical canopy photographs. The validation work presented in this paper justifies further development of the instrumentation and analyses to combine results from multi-angular systems with data from airborne systems to alleviate some of the problems associated with the vertical view. Current laser ranging systems can be used to derive canopy structural parameters such as height, cover, and foliage profile provided information based on multiple returns or the intensity of returns is used to minimize the bias induced by the size of the footprint and the detection threshold. Résumé. Les lidars aéroportés et au sol sont des outils utiles pour déterminer la structure des couverts forestiers. Une telle information n'est pas disponible directement à partir des autres méthodes de télédétection, mais elle est essentielle pour un inventaire forestier à l'ère moderne où les modèles de croissance et l'évaluation écologique ont de plus en plus d'importance. Cette étude a été réalisée pour examiner le potentiel des systèmes aéroportés et au sol actuels de mesure de distances à fournir des données à partir desquelles on peut dériver des paramètres utiles à l'inventaire forestier. Des données additionnelles ont été collectées incluant des données conventionnelles d'inventaire forestier, des photographies hémisphériques et des données optiques d'échantillonnage point-quadrat. Quatre sites d'étude différents ont été établis à l'intérieur d'un site d'étude existant dans les forêts d'état de Bago et Maragle, NSW, en Australie. Un ensemble simple et standard de modèles a été ajusté aux données pour établir la correspondance entre les méthodes et la pratique actuelle. On fait la démonstration des méthodes utilisées pour réduire le biais induit par l'interaction entre la taille de l'empreinte du balayeur laser aéroporté et le seuillage utilisé dans les systèmes de mesure de distances à l'aide du premier et du dernier retour et de l'intensité des retours. Une mesure analogue à la hauteur prédominante a été calculée à partir de la moyenne d'un certain nombre des retours SLA les plus élevés à l'intérieur de la zone. Cette estimation était en accord avec les valeurs de hauteur prédominante mesurées sur le terrain à l'intérieur de l'incertitude des mesures. Les données d'un système de télémétrie à balayage au sol ont été utilisées pour modéliser l'indice de surface foliaire (LAI). Ces estimations de LAI correspondaient aux estimations dérivées des photographies hémisphériques du couvert forestier. Le travail de validation présenté dans cette étude fait appel à des développements additionnels au niveau de l'instrumentation et des analyses pour pouvoir combiner les résultats des systèmes multi-angulaires avec les données des systèmes aéroportés pour remédier à certains des problèmes associés à la visée verticale. Les systèmes actuels de mesure de distances par laser peuvent être utilisés pour dériver des paramètres structuraux des couverts forestiers tels que la hauteur, le type de couvert et le profil du feuillage pourvu que l'on utilise l'information basée sur les retours multiples ou l'intensité des retours dans le but de minimiser le biais induit par la taille de l'empreinte et le seuil de détection. [Traduit par la Rédaction]

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Variance in images of woodlands - A problem and opportunity

Image Analysis & Stereology, Nov 1, 1985

Re-Scaling Lower Resolution Slope by Histogram Matching

Springer eBooks, Feb 20, 2008

Slope is a key parameter for regional scale hydrology, soil erosion, and relevant land surface pr... more Slope is a key parameter for regional scale hydrology, soil erosion, and relevant land surface process modelling. Slope information is usually extracted from moderate and lower resolution DEMs because of time and financial limitations. But research has shown that the slope will become flatter as the resolution of the DEMs becomes coarser. That is, slope reduction (SR) has occurred. Due

Introduction to remotely sensed data

SIDALC - Servicio de Informacion y Documentacion Agropecuaria de las Americas.

Mapping coral reef benthic substrates using hyperspectral space-borne images and spectral libraries

Estuarine Coastal and Shelf Science, Nov 1, 2006

The suitability of Hyperion, the first civilian hyperspectral sensor in space, for mapping coral ... more

The BRIAN handbook : an introduction to Landsat and the BRIAN (Barrier Reef Image ANalysis) system for users

Retrieval of Vegetation Structural Parameters and 3-D Reconstruction of Forest Canopies Using Ground-Based Echidna® Lidar

AGU Fall Meeting Abstracts, Dec 1, 2010

A ground-based, scanning, near-infrared lidar, the Echidna® validation instrument (EVI), built by... more A ground-based, scanning, near-infrared lidar, the Echidna® validation instrument (EVI), built by CSIRO Australia, retrieves structural parameters of forest stands rapidly and accurately, and by merging multiple scans into a single point cloud, the lidar also provides 3-D stand reconstructions. Echidna lidar technology scans with pulses of light at 1064 nm wavelength and digitizes the full return waveform sufficiently finely

Further Studies of Forest Structure Parameter Retrievals Using the Echidna® Ground-Based Lidar

AGUFM, Dec 1, 2012

Monitoring Forest Change and Ice Storm Disturbance to Forest Structure Using Echidna® Ground-Based Lidar

AGU Fall Meeting Abstracts, Dec 3, 2011

ABSTRACT The ground-based, upward-scanning, near-infrared (1064 nm), full-waveform lidar, the Ech... more ABSTRACT The ground-based, upward-scanning, near-infrared (1064 nm), full-waveform lidar, the Echidna° Validation Instrument (EVI), built by CSIRO Australia, is used to monitor forest change over a 2- or 3-year time period through changes in retrievals of mean stem diameter, stem density, basal area, above-ground standing biomass, leaf area index, foliage profile, and canopy height. The changes were validated by comparison with direct field measurements, or in the case of canopy height, with data from the Laser Vegetation Imaging Sensor (LVIS). Site-level EVI-retrieved values of mean DBH, stem count density, basal area and above-ground biomass matched the field measurements well, with R2 values of 0.84, 0.97, 0.96 and 0.98 respectively. Furthermore, the changes in EVI retrievals had the same trend as the change in field measurements over these 2-3 year periods. Based on five scans within each 1-ha plot, we focused on detecting forest change over a 2- or 3-year period at three New England forest stands: a second-growth conifer stand thinned as a shelterwood, an aging hemlock plantation, and a young second-growth hardwood stand. The first stand provided the opportunity to look for change in a stand containing many co-dominant and intermediate trees recently released by removal of selected over-story trees, while the other two stands suffered significant damage in an ice storm during the change period. At the shelterwood conifer site at Howland Experimental Forest, mean DBH, aboveground biomass, and leaf area index (LAI) all increased between 2007 and 2009. An ice storm struck the Harvard Forest in December, 2008, providing the opportunity to detect damage between 2007 and 2009 or 2010 with EVI scans at two sites : hemlock and hardwood. Retrieved leaf area index (LAI) was 13 percent lower in the hemlock site in 2009 and 10 percent lower in the hardwood site in 2010 as compared to 2007. The decrease of LAI quantifies a loss of biomass from the canopy, and broken tops were both recorded by the field teams and visible in the Echidna scans in the 2010 data. Stem density decreased and mean DBH increased at both sites, as smaller and weaker trees were felled by the ice. Canopy heights derived from the EVI-retrieved foliage profile closely matched those derived from the airborne Laser Vegetation Imaging Sensor (LVIS).

Variance in bidirectional reflectance over discontinuous plant canopies

An exploratory study of the variance of the bidirec- instruments. Also, directional

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The Lake Frome field campaign in support of Hyperion instrument calibration and validation

Lake Frome, a dry salt lake in South Australia, was chosen as a calibration site for Hyperion pri... more Lake Frome, a dry salt lake in South Australia, was chosen as a calibration site for Hyperion primarily for its brightness, but also for its temporal invariance and spatial homogeneity. Surface spectral data were collected along a transect through the centre of the lake, during a four-day period prior to the Hyperion overpass. Meteorological data collected by a portable weather station and a multi-frequency shadow-band radiometer installed at the lake shore, along with data from a nearby radiosonde and CIMEL sun photometer sites were used to measure atmospheric conditions at the time of overpass. The spectra were processed to reduce noise and modeled to at-sensor radiance for the 242 Hyperion spectral bands. The Hyperion images were geo-located using distinct ground features. Spectra for the ground sites were compared with those taken in the field, overall the agreement was excellent. The combination of field and laboratory measurements have provided some hypotheses of the systematic and causal way the lake behaves and changes spectrally.

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Radiometric calibration validation of the Hyperion instrument using ground truth at a site in Lake Frome, Australia

Proceedings of SPIE, Jan 21, 2002

The Hyperion instrument mounted on the EO-1 spacecraft was launched November 21, 2000 into an orb... more The Hyperion instrument mounted on the EO-1 spacecraft was launched November 21, 2000 into an orbit following LANDSAT-7 by 1 minute. Hyperion has a 7.5 km swath width, a 30 meter ground resolution and 10 nm spectral resolution extending from 400 nm to 2500 nm. The first portion of the mission was used to measure and characterize the on-orbit radiometric, spectral, image quality and geometric performance of the instrument. Lake Frome, a dry salt lake in South Australia was chosen as a calibration site for Hyperion. Surface spectral data were collected along a transect through the center of the lake prior to the Hyperion overpass. This paper discusses the incorporation of the Lake Frome ground measurements and analysis into the performance verification of the instrument.

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Modeling bidirectional reflectance of forests and woodlands using boolean models and geometric optics

Remote Sensing of Environment, Dec 1, 1990

Principles of geometric optics and Boolean models for random sets in a three-dimensional space pr... more Principles of geometric optics and Boolean models for random sets in a three-dimensional space provide the mathematical basis for a model of the bidirectional radiance or reflectance of a forest or woodland as remotely sensed by radiometric instruments. The model may be defined at two levels: whole-canopy and individual-leaf. At the wholecanopy level, the forest scene is treated as a collection of discrete canopy envelopes with simple geometric shapes that are arranged on a contrasting background. The scene includes four components: sunlit canopy, shadowed canopy, sunlit background, and shadowed background. The radiance or reflectance of the scene as a whole is modeled as the sum of the radiances or reflectances of the individual components as weighted by their areal proportions. The areal proportions of the components are determined by 1) principles of geometric optics as applied to the shapes of the canopy

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Retrieval of forest structural parameters using a ground-based lidar instrument (Echidna<sup>®</sup>)

Canadian Journal of Remote Sensing, Nov 21, 2008

A prototype upward-scanning, under-canopy, near-infrared light detection and ranging (lidar) syst... more A prototype upward-scanning, under-canopy, near-infrared light detection and ranging (lidar) system, the Echidna ® validation instrument (EVI), built by CSIRO Australia, retrieves forest stand structural parameters, including mean diameter at breast height (DBH), stand height, distance to tree, stem count density (stems/area), leaf-area index (LAI), and stand foliage profile (LAI with height) with very good accuracy in early trials. We validated retrievals with ground-truth data collected from two sites near Tumbarumba, New South Wales, Australia. In a ponderosa pine plantation, LAI values of 1.84 and 2.18 retrieved by two different methods using a single EVI scan bracketed a value of 1.98 estimated by allometric equations. In a natural, but managed, Eucalypus stand, eight scans provided mean LAI values of 2.28-2.47, depending on the method, which compare favorably with a value of 2.4 from hemispherical photography. The retrieved foliage profile clearly showed two canopy layers. A "find-trunks" algorithm processed the EVI scans at both sites to identify stems, determine their diameters, and measure their distances from the scan center. Distances were retrieved very accurately (r 2 = 0.99). The accuracy of EVI diameter retrieval decreased somewhat with distance as a function of angular resolution of the instrument but remained unbiased. We estimated stand basal area, mean diameter, and stem count density using the Relaskop method of variable radius plot sampling and found agreement with manual Relaskop values within about 2% after correcting for the obscuring of far trunks by near trunks (occlusion). These early trials prove the potential of under-canopy, upward-scanning lidar to retrieve forest structural parameters quickly and accurately. Résumé. Un lidar proche infrarouge prototype à balayage vers le haut et opérant sous le couvert, l'instrument EVI (Echidna ® validation instrument), construit par CSIRO Australia, a permis d'extraire les paramètres structurels des peuplements forestiers incluant le diamètre moyen à hauteur d'homme (DBH), la hauteur du peuplement, la distance par rapport à l'arbre, la densité des tiges (tiges/surface), l'indice de surface foliaire (LAI) et le profil du feuillage du peuplement (LAI plus hauteur) avec une très bonne précision lors des premiers essais. Nous avons validé les extractions avec des données de réalité de terrain acquises sur deux sites situés près de Tumbarumba, New South Wales, en Australie. Dans une plantation de pins ponderosa, les valeurs de LAI de 1,84 et de 2,18 extraites à l'aide de deux différentes méthodes utilisant un seul balayage de EVI ont enregistré une valeur de 1,98 estimée selon les équations allométriques. Dans un peuplement d'eucalyptus à l'état naturel mais sous gestion, huit balayages ont donné une valeur de LAI de 2,28 à 2,47, dépendant de la méthode, ce qui se compare favorablement avec la valeur de 2,4 dérivée de la photographie hémisphérique. Le profil du feuillage extrait montrait clairement deux couches de couvert. Un algorithme pour trouver les troncs (« find trunks ») a traité les balayages d'EVI pour les deux sites dans le but d'identifier les tiges, de déterminer leurs diamètres et de mesurer leurs distances à partir du centre du balayage. Les distances ont été extraites de façon très précise (r 2 = 0,99). La précision de l'extraction des diamètres d'EVI a diminué quelque peu avec la distance en fonction de la résolution angulaire de l'instrument, mais elle est demeurée non biaisée. Nous avons estimé la surface terrière du peuplement, le diamètre moyen et la densité des tiges à l'aide de la méthode Relaskop d'échantillonnage à rayon variable et nous avons trouvé une concordance avec les valeurs manuelles de Relaskop à l'intérieur de 2 % après correction pour le phénomène des troncs arrières qui sont cachés par les troncs plus en avant (occlusion). Ces premiers essais démontrent le potentiel du lidar opérant sous le couvert et à balayage vers le haut pour l'extraction rapide et précise des paramètres structurels de la forêt. [Traduit par la Rédaction] 440 S426

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Geometric-Optical Modeling of Forests as Remotely-Sensed Scenes Composed of Three-Dimensional, Discrete Objects

Springer eBooks, 1991

Mathematical modeling of the interaction of electromagnetic radiation with vegetation canopies is... more Mathematical modeling of the interaction of electromagnetic radiation with vegetation canopies is a research field that has been highly active in recent years. Modeling a canopy as a “turbid medium” of leaf and foliage elements in a slab geometry, the general equations of radiative transfer (Chandrasekhar 1950) have been approximated and solved in various ways and with varying types of description of the canopy. For example, both Suits (1972) and Verhoef (1984) use a four-stream approximation of the radiation flow and its interaction with canopy elements that has its origin in work by Schuster (1905) and Schwartzchild (1914). Cooper et al. (1982) and Kimes (1984) also use multistream approximations which, along with a variety of models for photon transport, are comprehensively reviewed in Myneni et al. (1989). In these models, the canopy elements are parameterized by such variables as the reflectance and transmittance of the leaf, leaf area index, and the leaf angle distribution. Many of these models are one-dimensional, in that the canopies vary only with height above the soil or ground surface.

Estimating forest LAI profiles and structural parameters using a ground-based laser called 'Echidna(R)

Tree Physiology, Dec 5, 2008

There are many techniques for measuring leaf area index (LAI) and forest canopy foliage profiles ... more There are many techniques for measuring leaf area index (LAI) and forest canopy foliage profiles but their accuracy is questionable. This paper briefly reviews current methods of estimating forest LAI and presents a novel, ground-based laser system, Echidna Ò that can make a wide range of measurements of forest structure, including LAI. Here, use of the system to provide field data and derived gap probabilities in the form of a 'hemispherical photograph with range' is demonstrated. The results show consistency and reproducibility and do not depend on special conditions for the natural light field.

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Atmospheric Correction and Water Surface Issues for Aquatic Applications of Landsat 8

Landsat 8 has a higher radiometric resolution than the previous Landsat series which offers the p... more Landsat 8 has a higher radiometric resolution than the previous Landsat series which offers the possibility that, if well processed, the data will be more suitable for effective monitoring of coastal and inland waters. In this paper, as part of a validation of Landsat 8 surface reflectance over water surfaces, some issues in calibration and radiative transfer modelling are investigated. Atmospheric correction using the MODTRAN 5.4 radiative transfer model is applied to Landsat 8 images at a site in Northern Queensland where ground aerosol and water reflectance measurements are available from an AERONET site to create a matched data series. The atmospheric corrections included aerosol and Rayleigh scattering, gas and aerosol absorption as well as sky and sun glint effects. The surface reflectance values from Landsat 8 were then compared with surface reflectance measurements. The results show that with a suitable solar irradiance model and accounting for surface roughness, the retrieved surface reflectance values have good agreement with surface measured values. It also achieves an acceptable reflectance signature for inland and ocean water. These signature are very important for inland water quality and shallow water bathymetry application.

Discrete-object modeling of remotely sensed scenes

Remotely sensed scenes can be modeled as collections of discrete, three-dimensional objects that ... more Remotely sensed scenes can be modeled as collections of discrete, three-dimensional objects that cast shadows on a background. Approaching scenes from this perspective has led to two related lines of research. First is the geometric/optical modeling of a forest canopy, in which conifers are modeled as cones whose size and spacing vary according to functions established by field measurements. This canopy model is 'L-resolution' in nature - the objects are smaller than the resolution cells of the image and cannot be resolved individually. Second is scene modeling in which image variance is taken as a function of the relationship between the size, shape and spacing of objects and the resolution cell size of the digital image derived from the scene. This modeling is 'H-resolution' in nature - the objects in the scene are assumed to be larger than the resolution cells of the image, and thus can be individually distinguished. Both approaches illustrate the utility of the discrete-object scene model in extracting information from remotely sensed scenes.

Some Research and Applications in the CSIRO (Australia) Earth Observation Centre on Scene Brightness Due to BRDF

Advances in global change research, 2000

Scientists at CSIRO (Australia) engage in a coordinated group of related projects involving land ... more Scientists at CSIRO (Australia) engage in a coordinated group of related projects involving land surface reflectance anisotropy. One of the underlying themes of the work is to test/establish the existence of a stable underlying "typology" of BRDF directly attributable to land surface spectral and structural parameters that will allow sensible selections of the "shape functions" used in correction and inversion algorithms. This requires the existence and use of well established field sites and a range of measurements other than radiometer data. There exist established sites now and there are serious canopy and land cover missions planned in the future which may provide more of this type of data. BRDF research in CSIRO EOC Research involves Data Normalisation (AVHRR, Scanners, Videos, Air Photos, calibrations Sites, Panels) Atmospheric Correction (AVHRR, Scanners) Determining Landcover Structure (Photography, Scanners) and BRDF characterisation. At many current Calibration and Validation sites modelled so far around the world, semi-empirical functions seem sufficient. However, for more complex land surfaces, atmospheric & BRDF effects will need to be separated and it is not clear whether and how consistent the results obtained will be. In all cases of the application of scene brightness correction from AVHRR NDVI to video data mosaicking, we have a fundamental issue of whether there is a consistent and simple typology of BRDF? Photography and scanner data, as well as video & AVHRR are all being collated and documented at established sites in Australia in mapped ecological regions to help test the feasibility of the proposed Landcover BRDF Typology and to assess the Australian Structural Typology using simple and detailed models.

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David Jupp

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