Satellite Laser Ranging

Prototyping modules to enable the use of satellite laser ranging (SLR) capabilities within Geoscience Australia’s (GA) Analysis Centre Software (ACS) for precise orbit determination for GNSS satellites.

The Challenge

Geoscience Australia (GA) is currently developing an Analysis Centre Software (ACS) package for multi-Global Navigation Satellite System (GNSS), multi-frequency data processing. The software package, when complete, will support both real-time and post-processing of multi-GNSS data. The precise determination of orbits of positioning satellites is fundamental to calculating position. GNSS orbits have typically been determined through the analysis of microwave observations. Satellite Laser Ranging (SLR), which measures the distance to a satellite using a laser, can then be used as a precise and independent way to validate and assess the quality of GNSS orbits if the satellite is equipped with a Laser Reflector Array (LRA). Today, all positioning constellations (GLONASS, Galileo, QZSS and Compass), as well as the newest GPS Block III satellites and many low earth orbit (LEO) satellites, are equipped with LRAs. There is also growing evidence that determination of satellite orbits can be significantly improved when SLR and microwave observations are combined. This project aims to research, develop and implement modules for GA’s ACS which allow the processing of SLR for orbit validation as well as orbit improvement via combined observations.


The project partners are Geoscience Australia and The Industrial Sciences Group.

The Solution

GA’s ACS is a GNSS data analytics capability which verifies and corrects positioning signals for users. This project is highly complementary, but independent to the On-going Development of the Multi-GNSS ACS project.

SLR observations are impacted by a smaller number of error sources than GNSS microwave observations for orbit determination and can also be useful in the determination of other geodetic parameters. This project will:

  1. Allow the processing of SLR observations for the validation of GNSS satellite orbits estimated by the ACS.
  2. Improve the accuracy of the satellite orbit and geodetic parameters through a joint estimation of SLR and GNSS microwave observations.

This project will also review the existing code base used to process microwave-based navigation satellites and make it applicable to processing optical based systems so that SLR observations can be processed. The novel component of the project comes in the second phase, which will focus on setting up the processing engine so that simultaneous processing of SLR and GNSS microwave observations can be used to produce a combined estimate of a satellite’s orbit and other geodetic parameters. Earth orientation parameters are an example of the other geodetic parameters and include centre of mass, earth rotation rate, scale, and potentially higher order Earth gravity field terms.


Positioning allows us to locate ourselves in the world and get to where we want to go. Through its Positioning Australia program, Geoscience Australia provides a range of GNSS data streams, products and services which support precise positioning across the nation. Real-time GNSS precise positioning has many societally-important applications such as geohazard monitoring (earthquake, volcano, tsunami early warning), real-time ionospheric and tropospheric monitoring, autonomous navigation, and surveying and mapping. This brings increased productivity, improved community safety and boosted innovation. The reported economic benefits of positioning technologies have the potential to generate upward of $73 billion of value to Australia by 2030. This project will develop and implement improved  modules into the ACS software, which has been made available via an open source licence. The ACS and results of this project will enable accurate, reliable and instantaneous precise positioning and lower the barriers to accessing advanced high precision positioning technology in Australia. This will enable Australian industry to progress and allow for innovation across all sectors such as agriculture, transport, emergency management, mining, engineering and logistics.


To learn more, contact FrontierSI at