The SPECCHIO Spectral Information System

© 2020 IEEE. Spectral Information Systems provide a framework to assemble, curate, and serve spectral data and their associated metadata. This article documents the evolution of the SPECCHIO system, devised to enable long-term usability and data-sharing of field spectroradiometer data. The new capabilities include a modern, web-based client-server architecture, a flexible metadata storage scheme for generic metadata handling, and a rich application programming interface, enabling scientists to directly access spectral data and metadata from their programming environment of choice. The SPECCHIO system source code has been moved into the open source domain to stimulate contributions from the spectroscopy community while binary distributions, including the SPECCHIO virtual machine, simplify the installation and use of the system for the end-users

Floodplain health in 4d: linking time series vegetation analysis with geomorphology and hydrogeology

Previous approaches to assessing vegetation dynamics have largely focussed on responses to rainfall and temperature, with only a brief consideration given to below-ground processes. However, in groundwater dependent ecosystems, such as those found on the Murray River floodplain, SE Australia, vegetation dynamics are also likely to be driven by changes to below-ground biogeochemical processes. Determining the connections between these aquifers and the pathways through which they are recharged is a key component in sustaining vegetation health in floodplain environments. This approach links climatological, hydrological and soil biogechemical processes to take into account soil-water, regolith-water, and plant-water interactions at a number of time scales in the order of seasons, years and decades. Associations between the hydrogeology, regolith and geomorphology with vegetation can then be elucidated both spatially and temporally. As a result, the primary drivers for land cover and vegetation health change can be determined to aid in developing management strategies on the floodplain. In the Murray River floodplain, it has been estimated that 70% of the floodplain ecosystems show signs of significant decline as a consequence of changes to the hydrological regime. Targeted environmental flows are planned to attempt to preserve iconic sites, but the success of these actions needs to be guided by improved knowledge of hydrogeology, including surface-groundwater connectivity, and groundwater quality distribution. This study reports on the use of time series vegetation analysis using ALOS, Landsat and MODIS data, integrated with 3-D mapping of key hydrogeological elements using an airborne electromagnetic (AEM) survey. The latter provides a snapshot of the soil profile and key elements of the hydrogeology including lithology distribution and groundwater quality, at relatively high resolutions. Correlations between vegetation health and soil and geomorphic units, surface salt distribution, saline groundwaters, river flush zones and perched aquifers reveal important associations and drivers of vegetation health

The SPECCHIO spectral information system

Spectral Information Systems provide a framework to assemble, curate, and serve spectral data and their associated metadata. This article documents the evolution of the SPECCHIO system, devised to enable long-term usability and data-sharing of field spectroradiometer data. The new capabilities include a modern, web-based client-server architecture, a flexible metadata storage scheme for generic metadata handling, and a rich application programming interface, enabling scientists to directly access spectral data and metadata from their programming environment of choice. The SPECCHIO system source code has been moved into the open source domain to stimulate contributions from the spectroscopy community while binary distributions, including the SPECCHIO virtual machine, simplify the installation and use of the system for the end-users

Building a SAR-Enabled Data Cube Capability in Australia Using SAR Analysis Ready Data

A research alliance between the Commonwealth Scientific and Industrial Research Organization and Geoscience Australia was established in relation to Digital Earth Australia, to develop a Synthetic Aperture Radar (SAR)-enabled Data Cube capability for Australia. This project has been developing SAR analysis ready data (ARD) products, including normalized radar backscatter (gamma nought, γ0), eigenvector-based dual-polarization decomposition and interferometric coherence, all generated from the European Space Agency (ESA) Sentinel-1 interferometric wide swath mode data available on the Copernicus Australasia Regional Data Hub. These are produced using the open source ESA SNAP toolbox. The processing workflows are described, along with a comparison of the γ0 backscatter and interferometric coherence ARD produced using SNAP and the proprietary software GAMMA. This comparison also evaluates the effects on γ0 backscatter due to variations related to: Near- and far-range look angles; SNAP’s default Shuttle Radar Topography Mission (SRTM) DEM and a refined Australia-wide DEM; as well as terrain. The agreement between SNAP and GAMMA is generally good, but also presents some systematic geometric and radiometric differences. The difference between SNAP’s default SRTM DEM and the refined DEM showed a small geometric shift along the radar view direction. The systematic geometric and radiometric issues detected can however be expected to have negligible effects on analysis, provided products from the two processors and two DEMs are used separately and not mixed within the same analysis. The results lead to the conclusion that the SNAP toolbox is suitable for producing the Sentinel-1 ARD products