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.

Occupancy surveys in November 2008 (Southwell and Emmerson 2013) found a total of 31 Adelie penguin breeding sites off the Vestfold Hills. The boundaries of breeding sub-colonies at 26 of these sites were subsequently mapped from vertical aerial photographs taken for abundance surveys on 18-21 November 2009. Two breeding sites were photographed obliquely from a helicopter using a hand-held camera on the 13 December 2012. Colony boundaries for these 2 sites were drawn and digitised by eye. Please refer to the Seabird Conservation Team Data Sharing Policy for use, acknowledgement and availability of data prior to downloading data.

This dataset comprises oblique aerial photographs of multiple Adelie penguin breeding sites in East Antarctica. The photographs were taken using hand-held digital cameras from fixed-wing aircraft and helicopters used by the Australian Antarctic Program. The aircraft flew at or above the minimum wildlife approach altitude of 750 m with a horizontal offset distance from the site of approximately 500-600m. The date and exact location of the aircraft when each photo was taken is embedded in the EXIF data of each photo. All photographs that were taken are included despite varying image quality due to environmental conditions, camera type and altitude. Generally an attempt was made to photograph the entire breeding site (usually an island, occasionally an outcrop of continental rock) with a series of zoomed, overlapping photos. Sometimes this was not possible when the site was large, and in these cases the overlapping photos covered the locations where colonies were known to exist from previous survey work. In some cases a site was over-flown at an altitude of 1200m so that a single photo of the entire site could be taken. These photos are useful in piecing together the detailed photos. The database of potential Adelie penguin breeding habitat in Southwell et al. (2016a) was used to associate photos to a particular breeding site and structure how the photos are stored. The breeding site database has a unique identifying code of every site of potential breeding habitat in East Antarctica, and the sites are aggregated into sub-groups and then groups. The file structure in which the photos are stored has a combination of ‘group’ and ‘split-year breeding season’ at the top level (eg VES 2015-16 contains all photos in group VES (Vestfold Hills and islands) taken in the 2015-16 breeding season). Within each group-year folder are sub-folders for each breeding site where photos were taken (eg IS_72276 is Gardner Island in the VES group). If an overview photo was taken there are separate sub-folders for overview and detailed photos in the site sub-folder. These data also superseded an earlier dataset of 2009-2016 data - https://data.aad.gov.au/metadata/records/AAS_4088_Adelie_oblique_photos Please refer to the Seabird Conservation Team Data Sharing Policy for use, acknowledgement and availability of data prior to downloading data.

This dataset contains sea ice surface brightness temperatures using a portable passive-microwave radiometer operating at 36Ghz-H,V mounted to the undercarriage of a Squirrel helicopter during SIPEX 2, 2012. This radiometer is the same sensor as satellite passive-microwave radiometer AMSR-E and AMSR2. Our passive-microwave radiometer is launched on the same helicopter as Jan Lieser's (RAPPAL), so please see the "SIPEX-2 RAPPLS Surveys (Radar, Aerial Photography, Pyrometer, and Laser Scanning system)" metadata file for details of the aircraft. The RAPPLS dataset also contains track (GPS position) and altitude data, which can be used in conjunction with this dataset. The CSV files in this dataset are the raw files as output by the sensor. These raw data files show only the relevant parameters (time and brightness temperatures).

Occupancy surveys in November 2008 (Southwell and Emmerson 2013) found a total of 13 Adelie penguin breeding sites in the Rauer Group. The boundaries of breeding sub-colonies at 12 of these sites were subsequently mapped from vertical aerial photographs taken for abundance surveys on 21-23 November 2009. The remaining breeding site (IS_72922) was photographed obliquely from a helicopter using a hand-held camera on 20 December 2010. Colony boundaries for this site were drawn and digitised by eye. Please refer to the Seabird Conservation Team Data Sharing Policy for use, acknowledgement and availability of data prior to downloading data.

These data have been superseded by a more recent dataset, described here - https://data.aad.gov.au/metadata/records/AAS_4088_Oblique_Aerial_Photos This dataset comprises oblique aerial photographs of multiple Adelie penguin breeding sites in East Antarctica. The photographs were taken using hand-held digital cameras from fixed-wing aircraft and helicopters used by the Australian Antarctic Program. The aircraft flew at or above the minimum wildlife approach altitude of 750 m with a horizontal offset distance from the site of approximately 500-600m. The date and exact location of the aircraft when each photo was taken is embedded in the EXIF data of each photo. All photographs that were taken are included despite varying image quality due to environmental conditions, camera type and altitude. Generally an attempt was made to photograph the entire breeding site (usually an island, occasionally an outcrop of continental rock) with a series of zoomed, overlapping photos. Sometimes this was not possible when the site was large, and in these cases the overlapping photos covered the locations where colonies were known to exist from previous survey work. In some cases a site was over-flown at an altitude of 1200m so that a single photo of the entire site could be taken. These photos are useful in piecing together the detailed photos. The database of potential Adelie penguin breeding habitat in Southwell et al. (2016a) was used to associate photos to a particular breeding site and structure how the photos are stored. The breeding site database has a unique identifying code of every site of potential breeding habitat in East Antarctica, and the sites are aggregated into sub-groups and then groups. The file structure in which the photos are stored has a combination of 'group' and 'split-year breeding season' at the top level (eg VES 2015-16 contains all photos in group VES (Vestfold Hills and islands) taken in the 2015-16 breeding season). Within each group-year folder are sub-folders for each breeding site where photos were taken (eg IS_72276 is Gardner Island in the VES group). If an overview photo was taken there are separate sub-folders for overview and detailed photos in the site sub-folder. Please refer to the Seabird Conservation Team Data Sharing Policy for use, acknowledgement and availability of data prior to downloading data.

Occupancy surveys in November 2008 (Southwell and Emmerson 2013) found a total of 31 Adelie penguin breeding sites off the Vestfold Hills. The boundaries of breeding sub-colonies at 26 of these sites were subsequently mapped from vertical aerial photographs A further two breeding sites (IS_72295 and McCallie Rocks_72205) were photographed obliquely from a helicopter using a hand-held camera on 10 January. Colony boundaries for 72295 were drawn and digitised by eye. Colony boundaries for 72295 were sketched onto a rough island polygon from the oblique photo without being rectified. Please refer to the Seabird Conservation Team Data Sharing Policy for use, acknowledgement and availability of data prior to downloading data.

Skin temperature data over the East Antarctic pack ice zone were recorded by the RAPPLS airborne instrument package using a KT-19II infrared pyrometer. The KT-19II infrared pyrometer was manufactured by heitronics, and sees a spectrum of 8-12um. IR and location data were logged to a Windows PC using a serial port logger developed by AAD science technical support. Due to some logging issues, substantial post-processing work was done by the AAD sea ice science group to ensure that recorded temperatures were correctly geolocated. Skin temperature data were not collected on two flights: Alpha [12 September 2007] and Foxtrot [14 September 2007] On two further flights, data were collected but the raw log files were so badly munged that we could not confidently tie locations to temperatures. These were: Tango [30 September 2007] and Uniform [1 October 2007] The data are presented in .csv files for each flight showing time and date. lat, lon, recorded temp [deg K], temp converted to C. To visualise the data, .kmz files that can be viewed in Google Earth or NASA's worldwind virtual globes are provided, one for each flight. Skin temperature is represented by a coloured dot at each measurement point. Clicking on each poijt will show its location and recorded temperature. The description field of each .kmz file provides a colour scale.

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.

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). Taken from the abstract of the PhD thesis accompanying the dataset: Antarctic sea ice and its snow cover are integral components of the global climate system, yet many aspects of their vertical dimensions are poorly understood, making their representation in global climate models poor. Remote sensing is the key to monitoring the dynamic nature of sea ice and its snow cover. Reliable and accurate snow thickness data from an airborne platform is currently a highly sought after data product. Remotely sensed snow thickness measurements can provide an indication of precipitation levels. These are predicted to increase with effects of climate change, and are difficult to measure as snow fall is frequently lost to wind-blown redistribution, sublimation and snow-ice formation. Additionally, accurate regional scale snow thickness data will increase the accuracy of sea ice thickness retrieval from satellite altimeter freeboard estimates. Airborne snow-depth investigation techniques are one method for providing regional estimation of these parameters. The airborne datasets are better suited to validating satellite algorithms, and are themselves easier to validate with in-situ measurement. The development and practicality of measuring snow thickness over sea ice in Antarctica using a helicopter-borne radar forms the subject of this thesis. The radar design, a 2-8 GHz Frequency Modulated Continuous Wave Radar, is a product of collaboration and the expertise at the Centre for Remote Sensing of Ice Sheets, Kansas University. This thesis presents a review of the theoretical basis of the interactions of electromagnetic waves with the snow and sea ice. The dominant general physical parameters pertinent to electromagnetic sensing are presented, and the necessary conditions for unambiguous identification of the air/snow and snow/ice interfaces by the radar are derived. It is found that the roughness's of the snow and ice surfaces are dominant determinants in the effectiveness of layer identification in this radar. Motivated by these results, the minimum sensitivity requirements for the radar are presented. Experiments with the radar mounted on a sled confirm that the radar is capable of unambiguously detecting snow thickness. Helicopter-borne experiments conducted during two voyages into the East Antarctic sea-ice zone show however, that the airborne data are highly affected by sweep frequency non-linearities, making identification of snow thickness difficult. A model for the source of these non-linearities in the radar is developed and verified, motivating the derivation of an error correcting algorithm. Application of the algorithm to the airborne data demonstrates that the radar is indeed receiving reflections from the air/snow and snow/ice interfaces. Consequently, this thesis presents the first in-situ validated snow thickness estimates over sea ice in Antarctica derived from a Frequency Modulated Continuous Wave radar on a helicopter-borne platform. Additionally, the ability of the radar to independently identify the air/snow and snow/ice interfaces allows for a relative estimate of roughness of the sea ice to be derived. This parameter is a critical component necessary for assessing the integrity of satellite snow-depth retrieval algorithms such as those using the data product provided by the Advanced Microwave Scanning Radiometer - Earth Observing System sensor on board NASA's Aqua satellite. This thesis provides a description, solution or mitigation of the many difficulties of operating a radar from a helicopter-borne platform, as well as tackling the difficulties presented in the study of heterogeneous media such as sea ice and its snow cover. In the future the accuracy of the snow-depth retrieval results can be increased as technical difficulties are overcome, and at the same time the radar architecture simplified. However, further validation studies are suggested to better understand the effect of heterogeneous nature of sea ice and its snow cover on the radar signature. RAASTI = Radar For Antarctic Snow Thickness Investigation