Science, resource management, and defense need algorithms capable of using airborne or satellite imagery to accurately map bathymetry, water quality, and substrate composition in optically shallow waters. Although a variety of inversion algorithms are available, there has been limited assessment of performance and no work has been published comparing their accuracy and efficiency. This paper compares the absolute and relative accuracies and computational efficiencies of one empirical and five radiative-transfer-based published approaches applied to coastal sites at Lee Stocking Island in the Bahamas and Moreton Bay in eastern Australia. These sites have published airborne hyperspectral data and field data. The assessment showed that (1) radiative-transfer-based methods were more accurate than the empirical approach for bathymetric retrieval, and the accuracies and processing times were inversely related to the complexity of the models used; (2) all inversion methods provided moderately accurate retrievals of bathymetry, water column inherent optical properties, and benthic reflectance in waters less than 13 m deep with homogeneous to heterogeneous benthic/substrate covers; (3) slightly higher accuracy retrievals were obtained from locally parameterized methods; and (4) no method compared here can be considered optimal for all situations. The results provide a guide to the conditions where each approach may be used (available image and field data and processing capability). A re-analysis of these same or additional sites with satellite hyperspectral data with lower spatial and radiometric resolution, but higher temporal resolution would be instructive to establish guidelines for repeatable regional to global scale shallow water mapping approaches.Optically shallow waters, those where the bottom is visible from the water surface and measurably influences the waterleaving radiance, include inland waters through to estuarine and tropical coral reef and temperate coastal ecosystems. Over

A 27-month study of the water properties across the continental shelf off Perth, Western 2 Australia (the "Hillarys Transect") has provided the first systematic inter-disciplinary climatology of the physical, chemical, optical and biological cycles across the shelf. This paper 4 describes the main features of the seasonal and cross-shelf variability of the physical oceanography and chemistry, while companion papers discuss some of the links between the 6 biology and physics of the region.The oceanography is dominated by the seasonally-varying Leeuwin Current flowing 8 southwards along the shelf break and outer shelf, and the northwards inshore Capes Current which is driven by the net southerly wind stress between about October and March (the austral 10 summer). As a result of the poleward boundary current, there is no large-scale upwelling comparable with the Humboldt and Benguela Current systems. Water temperature and salinity in 12 the shallow coastal waters are largely influenced by air-sea heat flux processes, while advection plays a more important role along the outer shelf; as a consequence, seasonal variations in the 14 inshore temperature and salinity are much larger than those offshore. Cross-shelf exchange of water and plankton is effected by (1) large-scale meandering of the Leeuwin Current, (2) 16 horizontal mixing as tongues of Leeuwin Current water penetrate across the shelf, (3) cascading of high-density coastal water offshore along the seabed, and (4) sporadic summer upwelling onto 18 the outer shelf (including the wake effect north of Rottnest Island).Nutrient and chlorophyll concentrations are low in comparison with other typical west 20 coast situations. While there is some indication of a seasonal cycle, the relatively short sampling period and high patchiness have precluded definitive patterns being described and longer-term 22 sampling may be required to resolve this.The effects of smaller-scale temperature and chlorophyll variability on satellite remote 24 sensing measurements (both "within-pixel" and "between pixel") in these coastal waters have been quantified using the underway (horizontal) and profile (vertical) data from the surveys. The 26 3 project has demonstrated the great potential of using remote sensing information for regular monitoring of the Western Australian continental shelf waters provided that adequate in situ 28 validation measurements are also undertaken.

Experiments were performed with prototype antenna tiles for the Mileura Widefield Array-Low Frequency Demonstrator (MWA-LFD) to better understand the widefield, wideband properties of their design and to characterize the radio frequency interference (RFI) between 80 and 300 MHz at the site in Western Australia. Observations acquired during the six month deployment confirmed the predicted sensitivity of the antennas, sky-noise dominated system temperatures, and phase-coherent interferometric measurements. The radio spectrum is remarkably free of strong terrestrial signals, with the exception of two narrow frequency bands allocated to satellite downlinks and rare bursts due to ground-based transmissions being scattered from aircraft and meteor trails. Results indicate the potential of the MWA-LFD to make significant achievements in its three key science objectives: epoch of reionziation science, heliospheric science, and radio transient detection.

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