An approach to the on-line detection and orbit determination of uncatalogued space debris objects

Transcription

1 An approach to the on-line detection and orbit determination of uncatalogued space debris objects Vasiliy S. Yurasov Vadim G. Vygon Victor D. Shargorodskiy Institute for Precision Instrument Engineering Moscow, Russia 1

2 Contents 1.Introduction 2.Workflow for optical observations 3.Features of on-line data processing 4.On-line SOs detection and orbit determination 5.Application of approach 2

3 Introduction Rapid progress in optical observations for late years: Measurements are accessible in the near realtime Sensitivity is increased from ~12-14 m up to ~18-19 m Metric accuracy is increased by order Performance has improved by one-two order The contribution of optical sensors to the space surveillance is significantly increased. 3

4 Introduction The mainstream of further development and application of optical sensors is an expansion of their opportunities on observation, tracking and cataloguing of small-sized space debris objects. Key directions of effectiveness increase: 1. Reduction of the time cycles for one field's viewing 2. Application of the effective survey strategies 3. On-line detection and orbit determination of uncatalogued space objects This paper is focused on the issues of the third direction. 4

5 Workflow for optical observations Observation planning and guidance Telescope pointing Execution of exposures and readout data from CCD Astrometric data processing On-line processing of angular measurements Robotic CCD Telescope 5

6 Workflow for optical observations The aims of on-line data processing: correlation of obtained measurements updating catalog orbits using correlated measurements on-line detection of uncorrelated objects to acquire the follow-up observations on-line orbit determination of uncorrelated objects when sufficient number of measurements is obtained. 6

7 Features of on-line data processing The number of observed and catalogued space objects will dramatically grow Possible large intervals between the observations Intensive solar radiation influence on SOs having large AMR Microsatellites GEO clusterization Returning of old GEO SOs to the equatorial plane 7

8 No of obs Features of on-line data processing: GEO clustering Groups of satellites: European - ASTRA, EUTELSAT, HOT BIRD, HISPASAT, SPAINSAT US DIRECT TV Indian INSAT Japan B-SAT Longitude, deg Distribution of longitudes of active GEO satellites 8

9 Features of on-line data processing: Returning of old GEO SOs to the equatorial plane Evolution of inclinations and RAAN longitudes with respect to Laplace plane 9

10 On-line SOs detection and orbit determination 1.Measurement correlation stages: Preparatory - ephemeris calculation for forthcoming session of observations for catalogued objects Preliminary on-line single out catalogued candidate-objects for correlation (by comparison of measured and ephemeris data) Correlation decision-making - by on-line orbit updating for candidate-objects using new measurements Results notification - the correlation results are sent right away to the planning and guidance software 10

11 On-line SOs detection and orbit determination 1.Acquiring the follow-up observations: The planning and guidance software automatically organizes a priority observation of uncorrelated objects (periodically or in tracking mode depending on angular velocity). To point sensor until orbit determination an extrapolation of measured parameters of object s apparent motion is used. New observations on uncatalogued and attendant objects are also sent right away to processing. 11

12 On-line SOs detection and orbit determination 0 Loop on uncorrelated measurements 4 Determine new orbit using all chosen measurements 8 Correlate the new orbit with catalogued objects 1 Search 3 short series of measurements 5 Does the solution created? 9 Does the new orbit correlated? 2 Determine an initial orbit 6 Yes Record the new orbit into catalog No 10 Yes Update orbit of catalogued object 3 Does an initial orbit determined? No 7 Improve the new orbit using additional measurements 11 End of loop on uncorrelated measurements No Yes Flowchart of new orbit determination task 12

13 Application of approach Wide-Field Telescope (WFT-35) at Altay Optical-Laser Center WFT-35 Detector 13

14 Application of approach Main characteristics of WFT-35 Optical schema of Slefogg-Richter-Terebizh Aperture diameter - 35 см FOV - 2,5 x2,5 CCD 4kх4k pixels Readout time - 2,5 с Exposition time range - 0, с Accuracy (rms) 0.5 Sensitivity 16 m 14

15 Application of approach The on-line measurement processing allows: decentralize partially the data processing increase the reliability of measurements correlation find out on-line the uncatalogued space objects and organize their purposeful observation joint the different short tracks of measurements obtained for the same space objects during onenight session increase the performance of survey optical sensor. 15

16 Thank you for attention! 16