AVHRR-based forest proportion map of the Pan-European area

Häme, Tuomas; Stenberg, Pauline; Andersson, Kristin; Rauste, Yrjö; Kennedy, Pamela J.; Folving, Sten; Sarkeala, Janne

doi:10.1016/s0034-4257(01)00195-x

Cited by 59 publications

(33 citation statements)

References 32 publications

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“…For this purpose, it was not considered meaningful to construct model canopies with very complex architecture at higher hierarchical levels, so instead we used simple Poissoncanopies with a homogeneous macroscopic structure. Although our simulations for these hypothetical canopies cannot be meaningfully evaluated against real data, results were in qualitative agreement with empirical observations (Häme et al, 2001;Loechel et al, 1997;Nilson et al, 1999;Tian et al, 2000;Zhang, Tian, Myneni, Knyazikhin, & Woodcock, 2002). That is, it seems that shoot structure can indeed explain large part of the different behavior of coniferous canopy reflectance as compared to broad-leaved canopies.…”

Section: Discussionsupporting

confidence: 87%

A method to account for shoot scale clumping in coniferous canopy reflectance models

Smolander¹,

Stenberg²

2003

Remote Sensing of Environment

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126

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The three-dimensional structure of a coniferous shoot gives rise to multiple scattering of light between the needles of the shoot, causing the shoot spectral reflectance to differ from that of a flat leaf. Forest reflectance models based on the radiative transfer equation handle shoot level clumping by correcting the radiation attenuation coefficient with a clumping index. The clumping index causes a reduction in the interception of radiation by the canopy at a fixed leaf area index (LAI). In this study, we show how within-shoot multiple scattering is related to shoot scale clumping and derive a similar, but wavelength dependent, correction to the scattering coefficient. The results provide a method for integrating shoot structure into current radiative transfer equation based forest reflectance models. The method was applied to explore the effect of shoot scale clumping on canopy spectral reflectance using simple model canopies with a homogeneous higher level structure. The clumping of needles into shoots caused a wavelength dependent reduction in canopy reflectance, as compared to that of a leaf canopy with similar interception. This is proposed to be one reason why coniferous and broad-leaved canopies occupy different regions in the spectral space and exhibit different dependency of spectral vegetation indices on LAI. D

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Section: Discussionsupporting

confidence: 87%

A method to account for shoot scale clumping in coniferous canopy reflectance models

Smolander¹,

Stenberg²

2003

Remote Sensing of Environment

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126

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“…The approach was based on segmentation of the GeoEye image, followed by k-means clustering and target variable estimation with the probability method [67]. Häme et al [65] described the methodology in more detail.…”

Section: Combining Relasphone Measurements With Satellite Imagery Formentioning

confidence: 99%

Relasphone—Mobile and Participative In Situ Forest Biomass Measurements Supporting Satellite Image Mapping

et al. 2016

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Due to the high cost of traditional forest plot measurements, the availability of up-to-date in situ forest inventory data has been a bottleneck for remote sensing image analysis in support of the important global forest biomass mapping. Capitalizing on the proliferation of smartphones, citizen science is a promising approach to increase spatial and temporal coverages of in situ forest observations in a cost-effective way. Digital cameras can be used as a relascope device to measure basal area, a forest density variable that is closely related to biomass. In this paper, we present the Relasphone mobile application with extensive accuracy assessment in two mixed forest sites from different biomes. Basal area measurements in Finland (boreal zone) were in good agreement with reference forest inventory plot data on pine (R 2 = 0.75, RMSE = 5.33 m 2 /ha), spruce (R 2 = 0.75, RMSE = 6.73 m 2 /ha) and birch (R 2 = 0.71, RMSE = 4.98 m 2 /ha), with total relative RMSE(%) = 29.66%. In Durango, Mexico (temperate zone), Relasphone stem volume measurements were best for pine (R 2 = 0.88, RMSE = 32.46 m 3 /ha) and total stem volume (R 2 = 0.87, RMSE = 35.21 m 3 /ha). Relasphone data were then successfully utilized as the only reference data in combination with optical satellite images to produce biomass maps. The Relasphone concept has been validated for future use by citizens in other locations.

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“…Maps of forest disturbances such as fire (Tansey et al, 2004;Roy et al, 2005) and insect defoliation (Wulder et al, 2006) represent special cases of forest change categorical variables. Percentage or proportion of forest cover (Häme et al, 2001;Hansen et al, 2003;McRoberts, 2006McRoberts, , 2009bMcRoberts, , 2010a and biomass (Dong et al, 2003;Blackard et al, 2008) are examples of continuous variables.…”

Section: Types Of Maps and Productsmentioning

confidence: 99%

Using remotely sensed data to construct and assess forest attribute maps and related spatial products

McRoberts

Cohen

Næsset

et al. 2010

Scandinavian Journal of Forest Research

112

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Tremendous advances in the construction and assessment of forest attribute maps and related spatial products have been realized in recent years, partly as a result of the use of remotely sensed data as an information source. This review focuses on the current state of techniques for the construction and assessment of remote sensing-based maps and addresses five topic areas: statistical classification and prediction techniques used to construct maps and related spatial products, accuracy assessment methods, map-based statistical inference, and two emerging topics, change detection and use of lidar data. Multiple general conclusions were drawn from the review: (1) remotely sensed data greatly contribute to the construction of forest attribute maps and related spatial products and to the reduction of inventory costs; (2) parametric prediction techniques, accuracy assessment methods and probability-based (design-based) inferential methods are generally familiar and mature, although inference is surprisingly seldom addressed; (3) non-parametric prediction techniques and modelbased inferential methods lack maturity and merit additional research; (4) change detection methods, with their great potential for adding a spatial component to change estimates, will mature rapidly; and (5) lidar applications, although currently immature, add an entirely new dimension to remote sensing research and will also mature rapidly. Crucial forest sustainability and climate change applications will continue to push all aspects of remote sensing to the forefront of forest research and operations.

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AVHRR-based forest proportion map of the Pan-European area

Cited by 59 publications

References 32 publications

A method to account for shoot scale clumping in coniferous canopy reflectance models

A method to account for shoot scale clumping in coniferous canopy reflectance models

Relasphone—Mobile and Participative In Situ Forest Biomass Measurements Supporting Satellite Image Mapping

Using remotely sensed data to construct and assess forest attribute maps and related spatial products

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