ARGUS: A UK Citizen Science study in support of the Surveillance of Space
Abstract
Argus is a Citizen Science project, involving scientists at the UK Ministry of Defence's Defence Science and Technology Laboratory (Dstl) working with members of the Basingstoke Astronomical Society (BAS). Argus examined the potential utility of employing a distributed array of amateur-grade astronomical imaging systems to inform the development of a future UK Space Situational Awareness (SSA) capability. Satellite positions were extracted from images captured of satellites tracked by the International Laser-Ranging Service (ILRS) and compared with the ILRS predictions. Orbital determinations were made from data gathered during the experiment using Dstl's in-house software and errors assessed.
This paper will describe the background to this project, including the process to establish effective interfaces between Dstl government scientists coordinating the experiment and local astronomy community members making target observations. Early data collections from the event will be discussed, including the issues discovered with the hard/software employed for electro-optical SSA operations, along with the process developed by the BAS and Dstl to overcome these issues that should be of relevance to EO operators. The work will be placed within the context of the current and future development of space situational awareness capabilities in the UK including the Royal Air Force's Space Operations Centre (SpOC) and the UK Space Agency. The data provided by the activity highlighted shortcomings in our existing data processing software, data processing pipeline and the criticality of timing accuracy together with the constraints that imposes on system operation. Additionally, it provided useful lessons learned in terms of the benefits and difficulties associated with Citizen Science collaborations. The experiment also determined the capabilities and limitations of using amateur-grade equipment for SSA. Argus has also highlighted significant infrastructure issues which would have to be addressed by any operational systems such as automation and remote operation, connectivity, data standardisation, sensor availability and sensor tasking. Comparison by Dstl of initial measurements to ILRS data revealed significant timing issues with the commercially-available astronomical software used by BAS members. BAS developed both hardware and software solutions to significantly increase the accuracy of timing synchronisation. These techniques included characterisation of camera timing delays and clock synchronisation, ultimately achieving synchronisation to within approximately 2 milliseconds. The project prompted significant development of Dstl's in-house orbit determination software, Mission Planner. Timing bias estimation and a Levenberg-Marquardt algorithm were implemented and both significantly increased the robustness and utility of the program. An example analysis for Cryosat 2 resulted in a successful orbit determination from a total of 275 optical (angles-only) observations of seven passes observed from four sites over a nine-day period. A Space-Track TLE was used to provide a start vector for the algorithm. Timing biases for three data sets with significant timing errors (12, 2 and 2 seconds) were estimated during the orbit determination run. Residuals between the orbit thus calculated and contemporary ILRS predictions showed a mean difference of 1 km. The project also prompted significant development of prototype image processing software which automatically detects and measures satellite trails in optical images. The software has been ported from two independent IDL and MATLAB instances into a Python implementation which includes a number of improvements. These include improved rejection of false positives, a lower detection threshold and the automatic association of related trails. Our paper will conclude by discussing the experiment's outcomes to inform the wider community on the use of an open community approach to SSA.- Publication:
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Advanced Maui Optical and Space Surveillance Technologies Conference
- Pub Date:
- September 2019
- Bibcode:
- 2019amos.confE..56F
- Keywords:
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- SSA;
- electro-optical;
- citizen science