The dataset submitted here is 'Sea-ice freeboard derived from airborne laser scanner'. Between 2007 and 2012, the Australian Antarctic program operated a scanning LiDAR system and other scientific instruments for sea-ice geophysical surveys in East Antarctica. For example see Lieser et al. [2013] for the 2012 survey. The dataset here provides the sea-ice freeboard (i.e. elevation above sea level) along various helicopter flight lines of the 2012 survey in the sea-ice zone between 113 degE and 123 degE. The data collection was based on: - Riegl LMS Q240i-60 scanning LiDAR, measuring sea ice elevation above the WGS84 reference ellipsoid; - Hasselblad H3D II 50 camera, taking aerial photographs at about 13 cm resolution every 3-5 seconds (older digital camera used in 2007); - inertial navigation and global positioning system, OxTS RT-4003. The following geophysical corrections were applied to the sea-ice elevations to derive the sea-ice freeboard: - geoid correction (from the EGM2008 Earth gravity model); - mean ocean dynamic topography correction (from the DTU Space model - DTU10MDT); - ocean tide correction (from the Earth and Space Research CATS2008 Antarctic tide model); - atmospheric pressure (inverse barometer effect) correction from ECMWF data (4-year average) and ship-board underway observations. The geophysical corrections have been validated along selected flight lines by extracting ocean surface elevations from leads between ice floes as identified in the aerial photography. Contained in this dataset are the following files: - a netCDF file for 8 selected flights of the 2012 survey containing sea-ice freeboard values; - a postscript file for 4 of the 8 selected flights showing the residuals from the applied geophysical corrections. These 4 flights were selected on the basis of having a good spread of observable leads along the entire flight line that enabled the extraction of ocean surface elevations.

This dataset contains the data collected during the RAPPLS (Radar, Aerial Photography, Pyrometer, and Laser Scanning system) flights that were undertaken as a part of the SIPEX II (Sea Ice Physics and Ecosystems Experiment II) Antarctic marine science voyage in September-November 2012. The RAPPLS project involved designing and using a system using a helicopter with mounted sensors to record data while flying over sea ice. The RAPPLS helicopter is an Aerospaciale AS 350 BA "Squirrel" helicopter with a range of scientific equipment mounted to it. These are generally imaging instruments that are used to derive snow and ice properties, such as roughness, surface elevation and skin temperature. The following is a list of instruments used and parameters measured: - 2-8 GHz frequency modulated continuous wave radar, measuring impedance differences between snow and sea ice; - Hasselblad H3D II 50 camera, taking aerial photographs at about 13 cm resolution every 3-5 seconds - Heitronics KT 19 pyranometer, measuring skin surface temperature - Riegl LMS Q240i-60 scanning LiDAR, measuring surface elevation of sea ice above sea level All data are geo-located with a combined inertial navigation and global positioning system, OxTS RT-4003. See Australian Antarctic Division Science Technical Support Project 07006 for detailed Engineering documents. Detailed flight information for each flight is available from WORD documents for each survey. Contained in this dataset are the following files: - A MS Word log file for all flights; - A QGIS map file showing all flights; - A folder for each flight containing the following (named - Date - Fxx - Mission: - A Microsoft Word document explaining the flight intentions, issues, and outcomes (flight log); - A folder of the photos taken by the Hasselblad camera; - A folder of raw and processed INS data: - RD files, which are raw INS and can be opened RT_PostProcess software; - PNG Files showing flight track, created with RT_View software based on NCOM files resulting from RT_PostProcess; - A folder with log files for Errors, Events, LaserScanner, Pyrometer, and INS. This folder also includes Q24 file of raw laser scanner data (purpose written software to analyse the data is available with the 2008 data set); - A folder with time synchronisation log file.

This data set is the airborne scanning LiDAR of a suite of different instruments deployed during the Sea Ice Physics and Ecosystems eXperiment (SIPEX) in 2007. Surveys have been flown over sea ice between 110-130 degrees E as part of the Australian Antarctic science project 2901. Public Summary for project 2901 This research will contribute to a large multi-disciplinary study of the physics and biology of the Antarctic sea ice zone in early Spring 2007. The physical characteristics of the sea ice will be directly measured using satellite-tracked drifting buoys, ice core analysis and drilled measurements, with detailed measurements of snow cover thickness and properties. Aircraft-based instrumentation will be used to expand our survey area beyond the ship's track and for remote sampling. The data collected will provide valuable ground-truthing for existing and future satellite missions and improve our understanding of the role of sea ice in the climate system. Project objectives: (i) to quantify the spatial variability in sea ice and snow cover properties over scales of metres to hundreds of kilometres in the region of 110-130 degrees E, in order to improve the accuracy of sea ice thickness estimates from satellite altimetry and polarimetric synthetic aperture radar (SAR) data. (ii) To determine the drift characteristics, and internal stress, of sea ice in the region 110-130 degrees E. (iii) To investigate the relationships between the physical sea ice environment and the structure of Southern Ocean ecosystems (joint with AAS Proposal 2767).