Earth Observation from Space - The Issue of Environmental Sustainability

Remote sensing scientists work under assumptions that should not be taken for granted and should, therefore, be challenged. These assumptions include the following: 1. Space, especially Low Earth Orbit (LEO), will always be available to governmental and commercial space entities that launch Earth remote sensing missions. 2. Space launches are benign with respect to environmental impacts. 3. Minimization of Type 1 error, which provides increased confidence in the experimental outcome, is the best way to assess the significance of environmental change. 4. Large-area remote sensing investigations, i.e. national, continental, global studies, are best done from space. 5. National space missions should trump international, cooperative space missions to ensure national control and distribution of the data products. At best, all of these points are arguable, and in some cases, they're wrong. Development of observational space systems that are compatible with sustainability principles should be a primary concern when Earth remote sensing space systems are envisioned, designed, and launched. The discussion is based on the hypothesis that reducing the environmental impacts of thedata acquisition step,which is at the very beginning of the information streamleading to decision and action, will enhance coherence in the information streamand strengthen the capacity of measurement processes to meet their stated functional goal, i.e. sustainable management of Earth resources. We suggest that unconventional points of view should be adopted and when appropriate, remedial measures considered that could help to reduce the environmental footprint of space remote sensing and of Earth observation and monitoring systems in general. This article discusses these five assumptions inthe contextof sustainablemanagementof Earth's resources. Takingeachassumptioninturn,we find the following: (1) Space debris may limit access to Low Earth Orbit over the next decades. (2) Relatively speaking, given that they're rare event, space launches may be benign, but study is merited on upper stratospheric and exospheric layers given the chemical activity associated with rocket combustion by-products. (3) Minimization of Type II error should be considered in situations where minimization of Type I error greatly hampers or precludes our ability to correct the environmental condition being studied. (4) In certain situations, airborne collects may be less expensive and more environmentally benign, and comparative studies should be done to determine which path is wisest. (5) International cooperation and data sharing will reduce instrument and launch costs and mission redundancy. Given fiscal concerns of most of the major space agencies e e.g. NASA, ESA, CNES e it seems prudent to combine resources

Towards an operational use of benthic foraminifera for organic pollution monitoring in open and enclosed marine environments: case histories from the outer shelf off Congo and the Firth of Clyde in Scotland.

Foraminifera are among the most abundant protists in marine benthic environments. Because of their short life cycles, high biodiversity and specific ecological requirements of individual species, foraminifera react quickly to environmental disturbance, and can be successfully employed as bio-indicators of environmental change, such as those brought about by anthropogenic pollution. In the last decennia, foraminifera have been increasingly used to monitor pollution in a wide range of marine environments, such as intertidal mudflats impacted by oil spillages, harbours affected by heavy metal pollution, or eutrophicated continental shelves. Our best examples of anthropogenic eutrophication are 1) a drill cutting disposal sites at the outer continental shelf off Congo, where we observed a zonation of foraminiferal faunas in the 750 m around the discharge point. In the immediate vicinity of the discharge points (within 70 m), faunas are characterised by low foraminiferal densities. Faunas between 70 m and 250 m of the disposal sites have very high foraminiferal densities, with high percentages of opportunistic taxa such as B. aculeata and B. marginata. Between 250 and 750 m, foraminiferal densities decrease, and the percentages of opportunistic species are lower; 2) a sewage sludge disposal on the sea floor in the Firth of Clyde (Scotland) where we used benthic foraminifera and macrofaunal/meiofaunal assemblages to evaluate the impact. These two communities present a very similar distributional pattern around the disposal site. In its immediate vicinity, both groups show impoverished faunas composed exclusively of species tolerant to strong oxygen depletion. This area is surrounded by an aureole of high density faunas dominated by opportunistic species. Still farther away, faunal density decreases, and equilibrium taxa gradually replace opportunistic species. At about 3 Km of the disposal site, both foraminiferal and macro-/meiofaunal taxa become comparable to those found at the reference station. We used these data to develop a quantitative pollution index, values of which are strongly correlated with the distance to the disposal site. This foraminiferal index offers the possibility to quantify the impact of anthropogenic eutrophication in marine environments, but its validity must be tested in wider range of naturally and anthropogenetically impacted marine environments.Foraminifera are among the most abundant protists in marine benthic environments. Because of their short life cycles, high biodiversity and specific ecological requirements of individual species, foraminifera react quickly to environmental disturbance, and can be successfully employed as bio-indicators of environmental change, such as those brought about by anthropogenic pollution. In the last decennia, foraminifera have been increasingly used to monitor pollution in a wide range of marine environments, such as intertidal mudflats impacted by oil spillages, harbours affected by heavy metal pollution, or eutrophicated continental shelves. Our best examples of anthropogenic eutrophication are 1) a drill cutting disposal sites at the outer continental shelf off Congo, where we observed a zonation of foraminiferal faunas in the 750 m around the discharge point. In the immediate vicinity of the discharge points (within 70 m), faunas are characterised by low foraminiferal densities. Faunas between 70 m and 250 m of the disposal sites have very high foraminiferal densities, with high percentages of opportunistic taxa such as B. aculeata and B. marginata. Between 250 and 750 m, foraminiferal densities decrease, and the percentages of opportunistic species are lower; 2) a sewage sludge disposal on the sea floor in the Firth of Clyde (Scotland) where we used benthic foraminifera and macrofaunal/meiofaunal assemblages to evaluate the impact. These two communities present a very similar distributional pattern around the disposal site. In its immediate vicinity, both groups show impoverished faunas composed exclusively of species tolerant to strong oxygen depletion. This area is surrounded by an aureole of high density faunas dominated by opportunistic species. Still farther away, faunal density decreases, and equilibrium taxa gradually replace opportunistic species. At about 3 Km of the disposal site, both foraminiferal and macro-/meiofaunal taxa become comparable to those found at the reference station. We used these data to develop a quantitative pollution index, values of which are strongly correlated with the distance to the disposal site. This foraminiferal index offers the possibility to quantify the impact of anthropogenic eutrophication in marine environments, but its validity must be tested in wider range of naturally and anthropogenetically impacted marine environments

Benthic foraminifera as bio-indicators of drill cutting disposal in tropical east Atlantic outer shelf environments

We present a study of benthic foraminiferal faunas from the outer continental shelf off Congo (tropical West Africa), with the aim to determine the impact of the discharge of oily drill cuttings on the sea floor environment, to judge the regenerating capacity of the benthic ecosystem, and to investigate the possibility to develop an environmental monitoring method for open marine continental shelf environments, based on benthic foraminifera. We studied the spatial distribution and microhabitats of living and dead foraminiferal faunas, sampled in April 2003, 4 years after the end of disposal activities, in the upper 3 cm of the sediment at 9 stations (about 180 m depth) offshore Congo, that were subject to various degrees of pollution by oily cuttings from 1993 until 1999. Our results describe a zonation of foraminiferal faunas in the 750 m around the former disposal sites. At the immediate vicinity of the discharge points (within 70 m), faunas are characterized by low foraminiferal densities. Faunas between 70 m and 250 m of the disposal sites have very high foraminiferal densities, with high percentages (about 80%) of opportunistic taxa such as Bulimina aculeata, Bulimina marginata, Textularia sagittula, Trifarina bradyi and Bolivina spp. Between 250 and 750 m from the disposal site, foraminiferal densities decrease, and the percentages of opportunistic species are lower (40–60% of indicator species). These results show that 4 years after the cessation of oily cutting disposal, strong environmental impact is limited to the 250 m around the disposal sites. We used these data to develop a quantitative pollution index, values of which are strongly correlated to distance to the disposal site. This foraminiferal index offers the possibility to quantify the impact of anthropogenic eutrophication in continental shelf environments, but its validity must be tested in other continental shelf environments

A method addressing signal occlusion by scene objects to quantify the 3D distribution of forest components from terrestrial lidar

SilviLaser 2015, La Grande Motte, FRA, 28-/09/2015 - 30/09/2015International audienceEstimating exact 3D distribution of canopy components using terrestrial lidar in forest is limited by signal occlusion. We propose a method to address this limitation: it uses voxels, beam returns and beam propagation through the scene. The proposed method was validated using simulated forest scenes and a lidar simulator

Low energy LIDARs for biomass applications

SilviLaser 2015, La Grande Motte, FRA, 28-/09/2015 - 30/09/2015International audienceA new approach for LIDAR altimetry mission for biomass applications ( tree height measurement ) is explored based on low emitted laser energy at high repetition fr equency. Low energy approach drastical ly reduces the laser induced risks. Altimetry performances meet preliminary science requirements . The proposed instrument design is compatible with a space mission

Integration of quality of service in avionics architecture

International audienceTraditionally, avionics systems have followed a federated approach - separate software functions al- located to dedicated (often physically disjoint) com-puting ”black-boxes”

Benthic foraminifera as bio-indicators of eutrophicated environments

Foraminifera are among the most abundant protists in marine benthic environments (Murray, 1991). Because of their short life cycles, high biodiversity and specific ecological requirements of individual species, foraminifera react quickly to environmental disturbance, and can be successfully employed as bio-indicators of environmental change, such as those brought about by anthropogenic pollution (as defined by Kramer and Botterweg, 1991). Foraminiferal assemblages are easy to collect; foraminifera are commonly abundant, providing a highly reliable database for statistical analysis, even when only small sample volumes are available. Furthermore, many foraminiferal taxa secrete a carbonate shell, and leave an excellent fossil record, that may be used to characterise baseline conditions, and to reconstruct the state of the ecosystem prior to sampling. Studies of the effects of pollution on benthic foraminiferal assemblages, and their possible use as pollution indicators were initiated in the early 1960’s by Resig (1960) and Watkins (1961). In the last decennia, foraminifera have been increasingly used to monitor pollution in a wide range of marine environments, such as intertidal mudflats impacted by oil spillages (Morvan et al., 2004), harbours affected by heavy metal pollution (Armynot Du Châtelet et al., 2004), or eutrophicated continental shelves (Sharifi et al., 1991; Yanko and Flexer, 1991). The goal of our study is to compare different types of eutrophicated environments, under anthropogenic or natural conditions:  we used benthic foraminifera as bio-indicators of anthropogenic eutrophication caused by drill cutting discharges (Congo and Gabon), by sewage sludge (Firth of Clyde; Scotland) and by fish farms (Loch Etive; Scotland) and compared the faunal patterns with those observed in the Rhone prodelta, en environment characterised by strong natural eutrophication due to  important continental nutrient input

Integration of formal fault analysis in ASSERT: Case studies and lessons learnt

International audienceThe ASSERT European Integrated Project (Automated proof-based System and Software Engineering for Real-Time systems; EC FP6, IST-004033) has investigated, elaborated and experimented advanced methods based on the AltaRica language and support tool OCAS for architecture and fault approach propagation description analysis, and integrated in the complete ASSERT process. The paper describes lessons learnt from three case studies: safety critical spacecraft, autonomous deep exploration spacecraft, and civil aircraft

Accounting for convective effects in zero-Mach-number thermoacoustic models

This paper presents a methodology to account for some mean-flow effects on thermo-acoustic instabilities when using the zero-Mach-number assumption. It is shown that when a computational domain is represented under the M=0 assumption, a nonzero-Mach-number element can simply be taken into account by imposing a proper acoustic impedance at the boundaries so as to mimic the mean flow effects in the outer, not computed flow domain. A model that accounts for the coupling between acoustic and entropy waves is presented. It relies on a “delayed entropy coupled boundary condition” (DECBC) for the Helmholtz equation satisfied by the acoustic pressure. The model proves able to capture low-frequency entropic modes even without mean-flow terms in the fluctuating pressure equation

Aged Drilled Cuttings Offshore Gabon: New Methodology for Assessing Their Impact

During E&P offshore activities, and in particular during drilling operations, the living conditions of the flora and fauna on the seabed may be disturbed.The paper describes the study made for assessing the actual impact of the discharged cuttings, the regenerating capacity of the ecosystem and the medium and long-term recolonization processes, based on in situ measurements. A previous study undertaken on cuttings recently discharged offshore Congo measured kinetics of space and time restoration of the drilling site. To validate the results we carried out a similar study dedicated on aged cuttings offshore Gabon. Usual process for monitoring biological effects of cuttings includes several approaches such as benthic macrofauna (> 1mm size) studies, physicochemical analysis of sediment and ecotoxicological tests. One of the key features of our study was to add, to this process, a study of the benthic meiofauna (0.1 to 1mm size). Experiments conducted demonstrated: -very low concentrations of hydrocarbons stemming out from the cuttings, -a very low toxicity of sediment, -no benthic macrofauna community alteration, -no change in the communities of actual and fossil foraminifera (meiofauna) and, -last but not least, that the study of the benthic meiofauna improves the quality of the assessment made