Eyes in the sky: ESA images forests in 3-D to analyse biomass
Nowadays there is a lot of research into analysing the capacity of ecosystems to act as 'carbon sinks' as they offer a potential way to mitigate climate change by storing carbon dioxide from the atmosphere. Producing accurate forest biomass estimates, and how they are changing over time, are a critical challenge to environmental scientists to whom national governments are turning for help in meeting their international obligations to stabilise greenhouse-gas emissions under the Kyoto Protocol.
Recent research revealed that not all forest types and not all locations would be suitable for afforestation, reforestation or conservation aimed at soaking up greenhouse gases, as some of the forests are and would be net CO2-contributors. This should make people think more critically about fashionable carbon offset schemes ('plant a tree to reduce your carbon footprint'), as some of these initiatives may actually worsen climate change (earlier post). On the other hand, understanding the amount of carbon forests store allows environmental economists to estimate the true 'ecoservice value' of an ecosystem (earlier post).
The European Space Agency is contributing to this kind of research by developing tools that allow forests to be seen from space in 3-D. It is also training scientists to use the new visualisation technique. 140 scientists and researchers from 22 countries have attended ESA's weeklong POLinSAR 2007 workshop, “Science and Applications of SAR Polarimetry and Polarimetric Interferometry,” hosted at ESRIN, ESA’s Earth Observation centre in Frascati, Italy, to hear the first space borne results and to attend interactive training sessions.
The technique is called 'polarimetric interferometry' and is performed using two polarimetric SAR (synthetic aperture radar) images acquired from slightly different directions. The study of these data sets permits scientists to retrieve information related to the 3-D structure of forest or other natural volume scatterers, such as underlying topography, forest height (image, click to enlarge) and to estimate forest biomass – a quantitative estimate of the entire amount of organic material in a particular forest habitat.
bioenergy :: biofuels :: energy :: sustainability :: earth observation :: SAR :: radar :: forests :: biomass :: carbon sink :: climate change ::
Workshop participants saw the first POLinSAR in-orbit results from the Japan Aerospace Exploration Agency’s (JAXA) Advanced Land Observing Satellite (ALOS). Launched on 24 January 2006, ALOS is supported as an ESA Third Party Mission.
Also at the workshop, ESA provided additional interactive training opportunities for the POLSARPRO tool developed by the University of Rennes 1, France, which includes a wide-ranging tutorial in Polarimetry and Polarimetric Interferometry. To date, some 700 registered users from 62 countries worldwide are using the tool.
Over the last 2 years, ESA has trained some 250 scientists to exploit Polarimetric airborne/spaceborne SAR data for science and applications development using in particular the POLSARPRO software and educational tool.
"POLinSAR is the starting point of future applications because we are at the point where new satellites will be launched, such as Germany’s TerraSAR-X and Canada’s Radarsat-2, that can provide polarimetry and interferometry," said Prof. Eric Pottier, head of the Radar Polarimetry Group at the University of Rennes. "Processing this kind of data will open many new application doors, so it is very important to train young students now to be able to handle this kind of data."
Image: ALOS PALSAR first forest height estimates by means of Single-Baseline Polarimetric Interferometry (POLinSAR) at L-Band obtained by German Aerospace Centre (DLR) on the Oberpfaffenhofen test site. The POLinSAR research group at DLR, supported by ESA, is studying the methodology for forest height measurement and validation. Credits: JAXA, ESA, DLR
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Recent research revealed that not all forest types and not all locations would be suitable for afforestation, reforestation or conservation aimed at soaking up greenhouse gases, as some of the forests are and would be net CO2-contributors. This should make people think more critically about fashionable carbon offset schemes ('plant a tree to reduce your carbon footprint'), as some of these initiatives may actually worsen climate change (earlier post). On the other hand, understanding the amount of carbon forests store allows environmental economists to estimate the true 'ecoservice value' of an ecosystem (earlier post).
The European Space Agency is contributing to this kind of research by developing tools that allow forests to be seen from space in 3-D. It is also training scientists to use the new visualisation technique. 140 scientists and researchers from 22 countries have attended ESA's weeklong POLinSAR 2007 workshop, “Science and Applications of SAR Polarimetry and Polarimetric Interferometry,” hosted at ESRIN, ESA’s Earth Observation centre in Frascati, Italy, to hear the first space borne results and to attend interactive training sessions.
The technique is called 'polarimetric interferometry' and is performed using two polarimetric SAR (synthetic aperture radar) images acquired from slightly different directions. The study of these data sets permits scientists to retrieve information related to the 3-D structure of forest or other natural volume scatterers, such as underlying topography, forest height (image, click to enlarge) and to estimate forest biomass – a quantitative estimate of the entire amount of organic material in a particular forest habitat.
"POLinSAR allows us to estimate key environmental parameters that are needed today. For instance, it allows us to make estimations of forest biomass on a global scale. The conclusions from these global estimates may also be important for climate change modellers and decision makers." -- Konstantinos Papathanassiou, a researcher with the Radar and Microwaves Institute at German Aerospace Centre.The capability of radar to penetrate ground cover and 'see' the underlying terrain, coupled with POLinSAR techniques to detect forest canopies, make it possible to classify trees and estimate their height using SAR imagery. This may sound of interest only to a narrow band of scientists, until one realizes that determining the types and heights of trees in a forest are critical ingredients in determining its biomass:
bioenergy :: biofuels :: energy :: sustainability :: earth observation :: SAR :: radar :: forests :: biomass :: carbon sink :: climate change ::
Workshop participants saw the first POLinSAR in-orbit results from the Japan Aerospace Exploration Agency’s (JAXA) Advanced Land Observing Satellite (ALOS). Launched on 24 January 2006, ALOS is supported as an ESA Third Party Mission.
Also at the workshop, ESA provided additional interactive training opportunities for the POLSARPRO tool developed by the University of Rennes 1, France, which includes a wide-ranging tutorial in Polarimetry and Polarimetric Interferometry. To date, some 700 registered users from 62 countries worldwide are using the tool.
Over the last 2 years, ESA has trained some 250 scientists to exploit Polarimetric airborne/spaceborne SAR data for science and applications development using in particular the POLSARPRO software and educational tool.
"POLinSAR is the starting point of future applications because we are at the point where new satellites will be launched, such as Germany’s TerraSAR-X and Canada’s Radarsat-2, that can provide polarimetry and interferometry," said Prof. Eric Pottier, head of the Radar Polarimetry Group at the University of Rennes. "Processing this kind of data will open many new application doors, so it is very important to train young students now to be able to handle this kind of data."
Image: ALOS PALSAR first forest height estimates by means of Single-Baseline Polarimetric Interferometry (POLinSAR) at L-Band obtained by German Aerospace Centre (DLR) on the Oberpfaffenhofen test site. The POLinSAR research group at DLR, supported by ESA, is studying the methodology for forest height measurement and validation. Credits: JAXA, ESA, DLR
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Tuesday, January 30, 2007
The bioeconomy at work: protein fibers from wheat gluten, similar to wool
Describing their simple production method in Biomacromolecules (open access article), Narendra Reddy and Yiqi Yang write that there is a long history of attempts to make natural cellulose fibers from lignocellulosic agricultural byproducts in an effort to add value to agricultural crops and to make the fiber industry more sustainable in the long run. Already during the 1930s and 1940s, efforts were made to use plant proteins such as soybeans, corn, and peanut and also milk proteins (casein) for fiber production. The higher cost, use of relatively environmentally unfriendly production processes, and inferior properties of the regenerated protein fibers as compared to those of the regenerated cellulose and synthetic fibers led to the abandoning of artificial protein fiber production.
Abundant feedstock, large market
However, the increasing use of cereal grains for biofuels and other industrial applications has led to the abundant availability of zein, soyprotein, and also wheat gluten as byproducts at low prices. Therefore, researchers have more recently attempted to produce fibers from zein, casein, and soyprotein and in addition from the blends of these proteins. Unfortunately, none of these attempts have been commercially successful to produce 100% protein fibers mainly due to the high cost and poor quality of the fibers. Reddy and Yang's wheat gluten fibers have now changed this situation.
Wheat gluten fibers would have a major cost advantage over both wool and silk, the two existing commercial natural protein fibers, according to the researchers. While wool sells for about US$5-8 per pound, and silk for US$10-$14 per pound, wheat gluten fetches less than 50 cents per pound and some 500,000 tons are available worldwide each year. This makes wheat gluten a cheap, abundant, and renewable source for producing protein fibers. In addition, wheat gluten has good stability to water and heat, excellent elasticity, and easy degradability, properties that are desirable for fibers. The annual world fiber market is about 67 million tons including about 2.3 million tons of the two natural protein fibers, wool and silk. Therefore, fibrous applications of the plant based material provide an opportunity for high value addition and offer a new, large market for consumption of wheat gluten:
biomass :: bioenergy :: biofuels :: energy :: sustainability :: wheat gluten :: fibers :: biomaterials :: bioeconomy ::
Although wheat gluten has previously not been used for fiber production, it has been used to produce bioplastics especially as films for food packing, as a binder for textile printing pastes, and as nanofibers via the electro-spinning process. The major limitations of the wheat gluten films are their relatively poor mechanical properties and higher cost as compared to those of the synthetic polymer-based films. Using wheat gluten as a binder is relatively expensive and also has limited market potential. This leaves the use of wheat gluten as a feedstock for biofibers.
The researchers developed a simple production method to obtain high-quality wheat gluten fibers, and the structure and properties of the fibers are promising. Wheat gluten fibers have breaking tenacity of about 115 MPa, breaking elongation of 23%, and a Young's modulus of 5 GPa, similar to those of wool. Wheat gluten fibers have better tensile properties than soyprotein- and casein-based biomaterials. In addition, the wheat gluten fibers have resistance similar to that of PLA (polylactic acid) fibers to water in weak alkaline and slightly lower resistance in weak acidic conditions at high temperatures.
In their paper, the authors discuss the method of producing 100% wheat gluten fibers, the effect of various production variables on the properties of the fibers, and the structure and properties of the fibers developed. The structure and properties of the fibers have been compared to the most common natural protein fiber, wool, and also to protein fibers produced from 100% zein and soyproteins.
They conclude that the protein fibers have mechanical properties similar to those of wool and better than those of 100% soyprotein and zein fibers have been produced successfully. They found that only a narrow range of concentration of wheat gluten, time, and temperature of aging is required to produce good quality fibers, and the properties of the fibers are improved by drawing and annealing. Although the fibers have low % crystallinity and poor orientation as compared to wool, they have good stability to weak acidic and weak alkaline conditions at high temperatures. The increasing availability of wheat gluten at low prices will provide an opportunity to develop cheap and environmentally friendly protein-based bioproducts. Wheat gluten fibers are suitable for biomedical applications because they have better properties than those of soyprotein-, zein-, and casein-based materials.
Image: Dyed Wheat Gluten Fibers, Courtesy of Yiqi Yang, Usage Restrictions: None.
More information:
Narendra Reddy and Yiqi Yang, "Novel Protein Fibers from Wheat Gluten", Biomacromolecules, Web Release Date: January 10, 2007; print release: February, 2007.
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posted by Biopact team at 4:30 PM 0 comments links to this post