Australian Hydrographic Service - LADS

Originally developed by Australia's Defence, Science and Technology Organisation (DSTO) for the Royal Australian Navy, the Laser Airborne Depth Sounder (LADS), fulfils a crucial need. Two hundred years after Cook, Flinders and other explorers of the Southern Hemisphere started charting Australia's vast coastline, nearly half of the continental shelf, or around one million square kilometres, remains unsurveyed or incompletely surveyed. LADS was developed to help speed up surveying and charting progress.

The LADS system provides valuable data for The Australian Hydrographic Service. 990 soundings per second , spaced from 2 to 6 metres apart in a swath between 47 to 288 metres wide; LADS provides accurate, high density digital depth and positional data of coastal waters up to 70 metres in depth. Flying at speeds between 140 and 210 knots depending on the sounding pattern.

Operational sounding height is between 1200 and 2200 feet (~400 to 730m) above the sea, unhindered by reefs or shallows. LADS surveys the sea floor at a rate in excess of 50 square kilometres an hour.

LADS can be deployed in a variety of hydrographic tasks for depths down to 70 metres and topographic heights up to 50m when conditions are suitable for laser survey.

The LADS aircraft is deployed from landing strips within operating range of the survey site. With accurate ground position determined using a Wide Area Global Positioning System (WaGPS) and post processed with information from a known base station. This is known as Post Processed Kinematic (PPK) and provides an accuracy better than the WaGPS alone.

LADS has been designed for isolated, self-contained operation, maintenance and support. .

Up to 7 hours of survey runs can be flown close to a deployment base. At a distance of 300 nautical miles, four hours of survey are available. LADS is used for both day and night operation.

Airborne data collection eliminates the difficulties associated with shipborne survey of shallow, dangerous or complex waters such as reef areas. It also permits the fast identification of key areas of navigational significance, such as undiscovered channels and passages.

Powerful analysis and conversion capabilities provide timely turn-around of data. This enables efficient, flexible survey sortie operations.

The digital data recorded by the airborne system is processed in ground-based analysis equipment. "Ground truthing" reference data and tidal information are incorporated in the data analysis and validation process. LADS data accuracy meets the International Hydrographic Organisation accuracy standards for hydrographic surveys.

LADS is operated with only a small number of personnel. A typical crew consists of the flight crew, two LADS airborne operators/data analysis staff and two ground support staff.