Airborne Digital Photography, Gulf of Carpentaria, 2017

In August/September 2017, digital aerial photography at 12.5 cm were captured at the same time as airborne LIDAR data along a nominal 1 km strip along the coastline of the Gulf of Carpentaria that extended from Groote Eytland (Queensland) through to Weipa (Northern Territory). The acquisitions focused on mangrove areas, including those that experienced dieback in 2015/16 but were not biased towards these areas. To achieve large comprehensive coverage of the coastal strips, multiple parallel flightlines were flown. At the Leichhardt River mouth, a 21-flightline grid was flown.

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Gulf Carpentaria ARA Aerial Image Leichardt River

This dataset consists of 18,500 geo-located 5626 x 3745 pixel digital aerial imagery at 12.5 cm spatial resolution. The list and details of the digital photography is given in the section ‘File Attributes’. Georeferencing and other information on image dimensions of the files are provided in the section on Spatial and Temporal extents.

Abstract or Summary

To establish a baseline of mangrove extent and structure along the Gulf of Carpentaria, northern Australia, a consortium consisting of the Airborne Research Australia (ARA), Queensland Herbarium, Charles Darwin University, The National Environmental Science Program (NESP) supported by TERN and the University of New South Wales (UNSW) coordinated the acquisition of small footprint discrete return airborne LIDAR along a coastal strip extending from Weipa (Queensland) to Groote Eylandt (Northern Territory). The acquisitions were largely in response to the mangrove dieback event in 2015/2016, which affected large sections along the Gulf of Carpentaria coastline as well as other areas in northern Australia. The aerial image data were acquired using a CANON EOS 5D DSLR Camera at the same time as the airborne LIDAR data and along a nominal 1 km strip, although this width was increased at least two parallel overpasses were undertaken in most areas. For some, multiple overpasses were flown, including inland from the coast along river estuaries. Over 7000 km of flight lines were flown during the acquisition period. All data are freely available through TERN Landscape Assessment.

Data quality

During the flights, efforts were made to fly at low tide and during the middle of the day to avoid variations in solar illumination. Cloud-free conditions were experienced during most of the flights although winds were strong over some areas. This could not be determined until the mission was underway and was planned on a day-by-day basis. 


The absolute horizontal accuracy is ±0.30 m at 1σ. The IMU unit/INS system met the flight limit specifications recommended by ASPRS LIDAR GUIDELINES: Horizontal Accuracy Reporting, namely ≤ 0.005o for roll; ≤ 0.005o for pitch; and ≤ 0.008o for heading (i.e. yaw).

Sampling strategy

Extensive planning of the flight lines was undertaken with the coordinating and funding partners and attempted to capture a nominal 1 km swath along the coastline of the Gulf of Carpentaria. The initial flight lines were based on a 1 km distance inland from the documented coastline but this was amended subsequently with reference to RapidEye data supplied by PlanetLabs and acquired in 2014 and 2015. During the mission, some further adjustments to the flight lines were made based on visual observations from the aircraft. Maximum effort was made to ensure acquisitions at low tide and during periods of optimal solar illumination.

Data Licence and Access Rights

Point of contact

All questions and comments about the data, the data processing or capture strategies should be addressed, in the first instance, to Jorg Hacker.

Credit

The following organisations contributed to funding and coordinating the data collection. The flights were conducted by Airborne Research Australia (ARA), which is supported by the Hackett Foundation of Adelaide.

Spatial and Temporal extents

File names and descriptions

https://www.airborneresearch.org.au/mangrove-dynamics/ARA_Lidar_Mangroves2017.html