We present a description of the AquaSat-1 mission concept, with emphasis on the instrument and concept of operations. AquaSat-1 seeks to provide data that can be used to deliver actionable information on water quality and aquatic ecosystems. The instrument is a state-of-the-art 350-1050 nm imaging spectrometer, with <= 10 nm Full-Width at Half Maximum (FWHM) spectral response function. It utilizes a fast f/1.8 optical system comprised of a three-mirror telescope coupled with a Dyson-type spectrometer. The passively cooled detector is a 3072x512 -pixel Teledyne digital-output array with 18 um pitch. Analysis of the radiometric performance demonstrates that the instrument can provide the required signal-to-noise ratio with margin for challenging aquatic objectives. High optical throughput and ground motion compensation, along with high spectral and spatial uniformity, permit high signal-to-noise ratio and excellent spectralradiometric fidelity. The orbit is 400 km sun-synchronous with Local Time of Ascending Node (LTAN) 00:00. During its 1 -year mission, AquaSat-1 will observe inland rivers, reservoirs, lakes, as well as corals in coastal areas.

Remote sensing of inland waters can provide timely and global water quality information to a wide variety of stakeholders. One of the parameters that determines the feasibility of using optical space-based instruments for monitoring inland waters is the ground sampling distance (GSD), defined as the width of a pixel projected on the Earth’s surface. We assume that to analyze a body of water with optical imagery, its characteristic width must be larger than 3 times the GSD to obtain an ‘unmixed’ pixel that doesn’t contain signal from the adjacent land. Here we obtain the size distribution of river lengths, river areas, and lake areas—as a function of width—for rivers and lakes in the Western United States (US) and in Australia. We base this analysis on the Surface Water and Ocean Topography River Database (SWORD) and HydroLAKES databases, extrapolated to 5 m-wide features. We show that the fraction of river length and river area larger than a certain width increases sharply as the width decreases, indicating that even small decreases in the GSD result in significant increases in the number of bodies that can be surveyed. On the other hand, the distribution of lake areas shows a ‘knee’ at around 400 m, indicating that gains from GSDs smaller than 130 m will be modest. We found that a satellite instrument with a GSD capability of 18 m can provide coverage of 4.4% of total river lengths, 38% of total river area, and 94% of total lake area within the study areas. We argue that decreasing the GSD incurs penalties associated with loss of signal-to-noise, larger instrument, smaller swath, and longer revisit times.

Binder jetting is establishing more and more in the ceramic industry to produce large complex shaped parts. A parameter with a great impact on the quality of the parts is the binder-powder interaction. The use of ceramic slurries as feedstock for this process, such as in the layerwise slurry deposition-print technology, allows a great flexibility in the composition. Such slurries are typically composed of ceramic powder, water, and small amounts of various additives. The understanding of the effect of these components on the printing quality is thus essential for the feedstock development. Four models were developed regarding the impact of additives, such as dispersants on printing. These models were confirmed or rebutted by experiments performed for an SiC slurry system with two different concentrations of a dispersant and a commercial phenolic resin used as a binder. It is shown that for this system the influence of the dispersant on the curing behavior and the clogging of the pores by dispersant can be neglected. The redispersion of the dispersant after the curing of the resin has no or only a minor effect. However, the wetting behavior determined by the surface energies of the system seem to be most crucial. In case the surface energy of the slurry additive is significantly lower than the surface energy of the binder, the strength of the green parts and the printing quality will be low. This was shown by inverse gas chromatography, contact angle measurement, rheological characterization, and mechanical tests with casted samples.

High temperature-resistant fabrics can be used as a reinforcement structure in ceramic matrix composites. They often need a coating for oxidation protection and mechanical decoupling from the matrix. Atomic layer deposition (ALD) provides very thin conformal coatings even deep down into complex or porous structures and thus might be a suitable technique for this purpose. Carbon fiber fabrics (size 300 mm × 80 mm) and SiC fiber fabrics (size 400 mm × 80 mm) were coated using ALD with a multilayer system: a first layer made of 320 cycles of alumina (Al2O3) deposition, a second layer made of 142 cycles of titania-furfuryl alcohol hybrid (TiO2-FFA), and a third layer made of 360 cycles of titanium phosphate (TixPOy). Scanning electron microscopy reveals that the coatings are uniform and that the thickness of each layer is almost independent of the place in the reactor while coating. Appearance and thickness do not show any dependence on the type of fiber used as a substrate. Energy dispersive x-ray spectroscopy confirmed the expected elemental composition of each layer. Thermogravimetric analysis under oxidizing environment revealed that the first layer increases the onset temperature of fiber oxidation significantly, while the following two layers improve the oxidative protection only to a much smaller degree. Varying the geometry and size of the sample holder and especially the stacking of several fabric specimens on top of each other allowed increasing the total area of coated fabric up to 560 cm2 per batch. It was demonstrated that four-layered fiber coatings could be obtained with high uniformity even on these much more complicated geometries.

This paper has been developed to address one deliverable in the CEOS ARD Strategy [1] and provides an initial evaluation of the views from the private sector on how the CEOS community needs to engage with the broader community to successfully advance the CEOS Analysis Ready Data (CARD) initiative to the next level. Further, the paper offers an overview of the next steps that the CEOS community should consider to ensure all three main stakeholder groups; a) Earth Observation (EO) data providers; b) Big Data hosts and c) aggregators and data users are actively involved in the CARD initiative. The full version of the paper can be found at the CEOS webpage [2]. Methods of evaluation included consultation with a small group from the private sector through an initial teleconference, follow-up emails and informal face-to-face discussions. Outcomes from this initial engagement show that the private sector recognises the CARD work as an important initiative and is open for future collaboration with the CEOS community. The next steps proposed in this paper include: –Share Information on CEOS Analysis Ready Data to build engagement support, –Understand the Industry Perspective, –Engage Industry in CARD Specifications, –Move CEOS specifications into the broader community.

As a feasibility study, a direct ink writing process using a conventional FDM-printer and colloidal C–SiC pastes was developed. The pastes have a low content of organic additives, which enables the omission of a pyrolysis step, i.e. the green parts can undergo the liquid silicon infiltration process directly after drying.The rheological behavior of the pastes was investigated regarding their viscosity, thixotropy and yield point. By analyzing important effects of 3D-printing, such as bridging and the possibility to print overhangs, the printability was determined. The near-net shape ability of the process was studied by comparing the dimensions after each processing step.The microstructure of the samples showed no detectable microstructural anomalies in this interface area. The phase analysis of the samples showed no residual carbon in the SiSiC parts. Printed SiSiC parts reached flexural strengths of 190 ​MPa, a hardness of 15.7 ​GPa and a Young’s Modulus of 246 ​GPa.

Background 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. Results 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. Conclusions 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 (individual 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.

NovaSAR-1 is a low-cost spaceborne Synthetic Aperture Radar (SAR) technology demonstrator developed by Surrey Satellite Technology Ltd, UK (SSTL), and Airbus Defence and Space Ltd, with funds of the UK Government [1]. After the successful launch of NovaSAR-1 satellite in September 2018 and completion of the commission phase in August 2019, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) are able to task, capture and access the unique S-band NovaSAR-1 imagery under the partnership of Australia's 10% capacity share in this new satellite mission [2], [3]. In the paper, we introduce the NovaSAR-1 data processing, and present initial results of NovaSAR-1 data performance evaluation and the recent emergency observations of extensive Australian bushfires.

With less than a decade left to attain the Sustainable Development Goals (SDGs), this communication aims to improve understanding of the enabling environment that is essential for Earth observations (EO) to be fully adopted within the institutional settings that drive the implementation of the SDGs and the Global Indicator Framework, an effective review mechanism for tracking progress at global to national and local levels. This paper also serves as an introduction to the Remote Sensing of Environment's Special Issue (SI) on Earth Observation for the Sustainable Development Goals. The seventeen contributions published in this SI showcase the application of EO data, methods, and tools to support countries in target setting for the SDGs, including baseline determination, as well as tracking of progress on SDG implementation and informing sustainable development planning and decision making. The majority of published articles focus on Goals 6 (Clean Water and Sanitation), 14 (Life below Water) and 15 (Life on Land). We also present our own analysis of existing EO systems available to generate data for SDG indicators addressed via the SI contributions, including main resolution characteristics, and assess factors that hinder the full integration of EO solutions for the SDGs within country processes, institutions of government, and policies. We conclude that an urgent need exists for the EO community to work more closely with local and regional governments and other relevant stakeholders to promote the operationalization of EO solutions for implementing the 2030 Agenda at global to local levels. Our review also illustrates the need for transitioning towards new EO for SDG frameworks that are focused on the knowledge element of the data-information-knowledge-wisdom paradigm, rather than the data and information aspects.

NovaSAR-1 SAR operates in S-band (3.2 GHz/9.4 cm) which is a rather uncommon frequency in microwave remote sensing. This study presents a very first assessment of S-band SAR backscatter observed over a tropical forest and wetlands region in the Amazon Basin, compared with near-simultaneous L-band SAR data from ALOS-2 PALSAR-2.Key findings: - S-band found to be sensitive to detection of below-canopy inundation in floodplain forests, with specular double-bounce scattering observed across the full (150 km) swath. - The phenomenon is only observed at HH polarisation. No canopy penetration or below canopy water detection observed in S-band VV polarisation data. - NovaSAR-1 operates with a steep incidence angle range (11°~32°) which results in strong direct backscatter from bare soil and open water surfaces.

The GFOI MGD provides practical advice related to the development of a National Forest Monitoring System to help meet national and international reporting requirements by: providing user-friendly guidance for linking UNFCCC decisions with IPCC guidance; focusing on how remotely sensed and ground-based data can be effectively combined to improve estimation of predominately forest related GHG emissions and removals, including those related to GHG inventories, REDD+ activities, and Nationally Determined Contributions (NDCs); addressing a gap that would otherwise exist in practical guidance on developing and implementing REDD+ MRV, while maintaining broader relevance to multipurpose monitoring of changes between forest land and non-forest land, particularly the methodologies that are outlined relating to land representation; presenting detailed advice to support decision making and technical implementation, and providing broad principles for the collection and use of data, which will remain relevant even as technologies and methods evolve; illustrating how countries can apply the principles outlined in the document by using existing examples of national experience; highlighting where relevant the broader applicability of the methods described in the development of a multipurpose monitoring system.

Mangroves globally provide a diverse array of ecosystem services but these are impacted upon by both natural and anthropogenic drivers of change. In Australia, mangroves are protected by law and hence the natural drivers predominate. To determine annual national level changes in mangroves between 1987 and 2016, their extent (by canopy cover type) and dynamics were quantified using dense time-series (nominally every 16 days cloud permitting) of 25 m spatial resolution Landsat sensor data available within Digital Earth Australia (DEA). The potential area that mangroves occupied over this period was established as the union of mangrove maps generated for 1996, 2007–2010 and 2015/16 through the Global Mangrove Watch (GMW). Within this area, the green vegetation fractional cover (GVpc) was retrieved from each available cloud-masked Landsat scene through linear spectral unmixing. The 10th percentile (GVpc10) was then determined for each calendar year by comparing these data in a time-series. The percentage Planimetric Canopy Cover (PCC%) for each Landsat pixel was then estimated using a relationship between GVpc10 and LiDAR-derived PCC% (<1 m resolution and based on acquisitions from all states supporting mangroves, excluding Victoria). The resulting annual maps of mangrove extent and cover for Australia are the first to be generated at a continental scale and on an annual basis. These indicated that the total area of mangrove forest (canopy cover >20%; resolvable at the Landsat resolution) varied from a minima of 10,715 ± 36 km2 (95% confidence interval) in 1992 to a maxima of 11,388 km2 ± 38 km2 (95% CI) in 2010, declining to 11,142 ± 57 km2 (95% CI) in 2017. In 2010 (maximum extent), the forests were classified as closed canopy (38.8%), open canopy (49.0%) and woodland mangrove (12.2%). The majority of change occurred along the northern Australian coastline and was concentrated in the major gulfs and sounds. The 30 national maps of annual mangrove extent represent a reference dataset, which is publicly available through the Terrestrial Environment Research Network (TERN) landscapes portal. Future efforts are focusing on the routine production of annual mangrove maps beyond 2019 as part of Australia's efforts to monitor the coastal environment.

Launched in September 2018, NovaSAR-1 is a novel Earth Observation (EO) satellite hosting the only operational spaceborne S-band Synthetic Aperture Radar (SAR), plus an Automatic Identification System receiver for use in ship tracking. Australia's 10% capacity share in this new satellite mission provides the nation with a first-ever sovereign civilian EO satellite capability. The Commonwealth Scientific and Industrial Research Organisation (CSIRO) operates this service as a National Facility for research, supporting science projects that are scoping the application of S-band SAR to an array of terrestrial and marine environments, and implementing background mapping of the continent, which will be key to supporting a wide range of existing research. Utilising a suite of newly designed and implemented acquisition modes, CSIRO have (since October 2019) captured NovaSAR-1 imagery in all Australian states and territories and throughout parts of the neighbouring Pacific region. For Australia, this mission provides significant opportunities to gain experience in satellite operations and creates new opportunities in the field of remote sensing, advancing Australia's imaging radar capability and further developing national EO data analytics expertise.

A novel, vacuum-assisted single-step slurry infiltration process (SIP) for the manufacturing of OFCs (Oxide Fiber Composites) was developed. It provides a simple and cost-effective way to infiltrate near-net shape fiber preforms, such as radial braided fiber architectures. NextelTM 610 fabrics were infiltrated with an alumina-zirconia slurry in order to obtain NextelTM 610/Al2O3-ZrO2 composites, which were investigated by SEM and three-point-bending tests. Vacuum pressures varying from 50 mbar to 700 mbar were tested for the SIP as well as varying solid contents between 50 wt.% to 71 wt.% and different aids (manual support by Teflon roller, pressure infiltration) during the initial infiltration. As advancement of the SIP, a double-step infiltration process (DIP) was developed, to ensure a more homogeneous infiltration of the fiber bundles. A comparison of microstructure and mechanical properties of the OFCs manufactured by SIP and DIP with OFCs manufactured by a prepreg process was made. To demonstrate the feasibility of the developed DIP process for complex fiber preforms, a burner nozzle was fabricated by infiltrating a radial braided preform.

The global challenge of understanding and forecasting ecosystem responses to climate extremes and climate change is addressed in this review of research enabled through environmental research infrastructure (RI) provided by Australia’s Terrestrial Ecosystem Research Network (TERN). Two primary climatic drivers of ecosystem structure and function in Australia are fire and aridity, to which Australian flora and fauna have shown marked adaptability. Australian vegetation shows resilience to climate extremes of flooding rains, droughts and heatwaves such that variability in primary productivity of Australian vegetation has a tangible effect on the global carbon cycle. Nonetheless, Australian flora and ecosystems could be vulnerable to projected climate change (e.g. to increasing vapour pressure deficit). Refugia are also vulnerable to climate change, with conditions in these areas already near the tipping point for a change in community composition. Ensuring genetic diversity during directional change in climate (e.g. increasing aridity) requires proactive approaches to conservation and restoration projects. To address these challenges, TERN provides environmental RI at three scales of observation: (i) environmental monitoring using remote sensing techniques at a landscape and continental scale; (ii) a spatially extensive network of ecosystem monitoring plots; and (iii) intensely measured sites collecting detailed data on ecosystem processes. Through partnerships with international environmental RIs, TERN enables research that addresses global challenges, on the first steps toward the forecasting of ecosystem–climate interactions.

In recent decades there have been numerous global and regional targets and initiatives to halt and reverse land degradation. The land degradation neutrality (LPN) target, embedded in the United Nations Sustainable Development Goals (SDGs), provides a framework for countries to avoid or reduce degradation through sustainable land management, coupled with efforts to restore or rehabilitate degraded land. Here we present the key recommendations from the Good Practice Guidance (GPG) for monitoring and reporting on SDG indicator 15.3.1 ("proportion of land that is degraded over total land area") and discuss how it could be used in the context of implementing the LPN target. SDG indicator 15.3.1 is assessed in terms of change in three sub-indicators: land cover, land productivity and carbon stocks. Each of these sub-indicators represents a unique perspective on the manifestation and assessment of land degradation. Global time-series datasets are a valuable recent development for monitoring landscape-scale changes, but variations in land conditions between countries, and differences in the sensitivities of these time-series datasets, present challenges in the selection of the most appropriate methods and datasets. Methods to combine the three sub-indicators for SDG indicator 15.3.1 need to account for variations in conditions over space and time, and potential differences in the representation of degradation among the sub-indicators and between countries. Without being prescriptive about the sources of data, the GPG aims to ensure technical soundness and consistency in estimation methods as well as comparability of results across countries and over time. The information provided by the three sub-indicators will assist countries to better understand their distribution and types of land degradation, and support countries to achieve their LDN targets. This paper presents some of the key methodological details of the GPG and describes how they can be used in the context of LDN implementation.

NovaSAR-1 is a technology demonstrator by Surrey Satellite Technology Ltd, UK (SSTL), and Airbus Defence and Space Ltd, funded by the UK Government via the UK Space Agency (UKSA). The NovaSAR-1 satellite utilises S-band Synthetic Aperture Radar (SAR) providing medium and high resolution images of Earth from space. In September 2017, Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) became a partner with the UK and India in the NovaSAR-1 mission through a 10 percent time-share [1]. The agreement allows CSIRO to direct the NovaSAR-1 satellite to collect data imagery on a world-wide basis through a range of observation modes with priority over the Australian region for the duration of the 7 year mission. CSIRO has designed a detailed background-, and foreground acquisition strategy for our share of the NovaSAR-1 satellite. This will provide at least two annual wall-to-wall coverages of Australia's landmass as well as supporting a wide range of existing research and basic satellite data acquisition training, to further develop Australia's Earth observation data analytics expertise, and create new opportunities in the field of remote sensing.

Plants actively regulate excess absorbed energy to protect photosynthetic machinery through heat dissipation in a process known as non-photochemical quenching (NPQ), a process useful for quantifying plant health and productivity. NPQ can be indirectly measured in the visible wavelengths between 500 nm and 560 nm, most commonly through the Photochemical Reflectance Index (PRI). However, there remains a lack of consensus regarding the optimal functional form and band selection to calculate PRI for the purpose of measuring NPQ mechanisms. Here, we quantitatively evaluate the effectiveness of leaf-level parametric and non-parametric spectral formulations, band locations, and number of bands to track the xanthophyll pigment cycle in a tall mature Eucalypt forest. Subsequently, our recommended approach is the new 'tri-PRI' index robust to constitutive pigment pool sizes across the canopy profile. tri-PRI is a Triangular Vegetation Index (TVI) (tri-PRI = 0.5[(520 - 490)(R-545nm - R-490nm) - (545 - 490)(R-520nm - R-490nm)]) using three reflectance bands around 490 nm, 520 nm and 545 nm, and has a physiological photosynthetic basis. We found that tri-PRI significantly outperformed PRI and other two band combinations for quantifying the xanthophyll EPoxidation State 'EPS' (tri-PRI R-2 = 0.75 versus PRI R-2 = 0.23), as well as the Phi NPQ and Phi PSII active chlorophyll fluorescence quenching yields. The new band placement enhanced the dynamic EPS absorption peak, while the third band provided an additional normalisation to minimise the confounding effects of pigments with overlapping spectral features. tri-PRI also performed comparably to parametric and non-parametric hyperspectral techniques and formulations using continuous spectral regions, highlighting the utility of targeted multispectral indices over hyperspectral approaches. This leaf-level study represents a foundational step toward indirectly measuring dynamic photosynthetic activity across the canopy profile in a tall mature Eucalypt forest to inform upscaling efforts from above-canopy remote sensing platforms. The application of tri-PRI and other top-performing multi-band TVI formulations for predicting EPS presented here should be explored across different canopy types, temporal-, and spatial scales.