Surveying and Geospatial Engineering Initiative

Research Initiative in Surveying and Geospatial Engineering

SGEI

A wide range of geospatial technologies and applications are transforming how we, as individuals work and play; how companies plan and execute infrastructure projects; how policy makers ensure sustainable development that delivers environmental, social and economic benefits; how communities monitor and manage the natural and built environments; how governments ensure the delivery of health and transport services, security and energy, to its citizens; how science answers crucial questions regarding our fragile but dynamic planet.

The School’s Surveying and Geospatial Engineering (SAGE) Research Group has been conducting world-class research in the sub-disciplines of geodesy, photogrammetry, positioning measurement, laser scanning, geospatial information systems and remote sensing since the 1960s. Many of today’s research topics are related to these traditional strengths.

Modern Geodesy is – as a result of ever more sensitive space and terrestrial technologies – being increasingly used for global change studies, such as measuring the rate of sea level rise, the atmospheric ionosphere and troposphere parameters, the ice sheets, and the mass transport within the water cycle. Modern Geodesy is therefore an Earth Observation Science.

Earth's Gravity Field Anomalies

However its traditional role as the foundation for mapping is as important as ever for two reasons. One is that Geodesy is associated with the definition of geometric, time, gravity and height reference systems. Today Geodesy is responsible for the definition and maintenance of the International Terrestrial Reference Frame (ITRF), which in turn underpins a nation’s geodetic datum. The second reason is the Geodesy, the ITRF and precise positioning are identified with the technology of Global Navigation Satellite Systems (GNSSs) such as the U.S.’s GPS.

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Navigation – although one of the oldest of the applied sciences– nowadays is critical to the functioning of a modern society. Professional navigators use a range of Positioning, Navigation and Timing (PNT) technologies for aircraft, marine and land transport. However, as a result of the revolution wrought by the introduction of GPS (as well as other GNSSs), PNT technologies are critical for machine automation, emergency services & military operations, mapping & surveying, transport management, personal mobility, telecommunications & timing, to name but a few applications.

 

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Earth Observation – in the context of the SAGE group’s research – refers here to a subset of Remote Sensing technologies traditionally linked to Geodesy, Photogrammetry and Surveying:

  1. radar remote sensing,
  2. digital photogrammetry using aerial or satellite cameras,
  3. airborne and terrestrial laser scanning, and
  4. geodesy.

The opportunities for growth are driven on the one hand by the rapid development of imaging sensor technologies and their deployment on a myriad of satellite and airborne platforms, and on the other by society’s need to better manage the environment and its resources, to detect and monitor changes in land cover, land use and surface geometry, and to gain a better understanding of the dynamic earth processes.

 

SAGE undertakes research in the following broad topic areas:

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The Satellite Navigation Technology and Applications Theme recognises society’s increasing need for Positioning, Navigation and Timing (PNT). The primary focus is satellite receiver technology, measurement processing and applications of Global Navigation Satellite Systems (GNSSs). As the number of GNSS satellite constellations expand and new navigation signals are broadcast to users, there will be many basic and applied research challenges to receiver designers, that include RF and baseband algorithms associated both with traditional GPS and the unique features of new signals from GPS and other GNSS/RNSS; innovative designs for signal acquisition and tracking; and the integration of several systems in one receiver. However research into PNT technologies beyond GNSS is necessary. There is a need for PNT solutions where GNSS cannot be used, such as indoors or other difficult environments where satellite navigation signals are obstructed or of low quality. There is a wide range of navigation sensor technologies that can be used either on their own, or within integrated multisensor systems, to augment GNSS, or replace space-based PNT systems. Research challenges abound in all areas of multisensor system development, from the hardware through to measurement processing and the generation of final solutions. For more information about this theme, contact Professor Chris Rizos, or Associate Professor Jinling Wang. See also the Satellite Navigation and Positioning (SNAP) Laboratory website.

 

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The Geodetic Infrastructure and Analysis Theme has a particular focus on Precise Positioning using GNSS, to address the accuracy requirements of Geodesy, Surveying, Mapping and Precision Navigation. These are typically at the sub-metre level, but include accuracies as high at the centimeter-level, and require special GPS/GNSS hardware, measurement modeling & analysis, operational procedures, and geodetic infrastructure – all research strengths of the SAGE group. For example, the deployment and operation of government-run and private permanent GNSS reference receiver networks is a recent development recognises the central role of precise GNSS positioning. Such reference stations are critical components of a National Positioning Infrastructure (NPI). Plans for a new geodetic datum for Australia and New Zealand; the implementation of NPI; the deployment of next generation GNSS; the development of new techniques of Precise Point Positioning (PPP); and advances in international geodesy all have complex impacts on high accuracy users. For more information about Geodetic Infrastructure and Analysis, contact Professor Chris Rizos or Dr Craig Roberts. See also the Satellite Navigation and Positioning (SNAP) Laboratory website (coming soon).

 

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The Geospatial Information Systems and Remote Sensing Theme recognises the special role of Mapping and Remote Sensing, both from the data acquisition point of view, but as a driver for the development of Geospatial Information Systems (GIS) to manage huge volumes of geoinformation. GIS technology is now more than ever an enabling technology for utilities and communications, transportation, public safety, natural resources, health and human services, etc.; and SAGE research focuses on applications of GIS to real-world problems. Lidar – essentially a rapidly scanning laser that measures distances to the ground and objects to create “point clouds” – is also a geospatial technology with many applications, but also many research challenges, ranging from the analysis of Lidar sensor data, through to the development of applications-specific algorithms for terrain and forest mapping, 3D city modelling and rapid mobile mapping of transport corridors and engineering structures. Remote sensing technology such as synthetic aperture radar (SAR) is a critically important satellite earth observation and mapping technique for a wide range of applications including the monitoring vegetation & land use; biomass & soil moisture; water surfaces & flooding; pollution at sea & ship detection; and terrain mapping & ground deformation measurement. For more information about GIS and Lidar, contact Associate Professor Samsung Lim. For more information about Remote Sensing, contact Associate Professor Linlin Ge.

Download a document with further details of the SAGE research topics here.