Speckle Interferometry Tracking of On-Orbit Servicing in Geostationary Orbit


  1. Scott, R.L.
  2. Ellery, A.A.
Corporate Authors
Defence Research and Development Canada, Ottawa Research Centre, Ottawa ON (CAN);Carleton Univ, Ottawa ONT (CAN)
On-orbit servicing missions in geostationary orbit with intersatellite separations less than 1 km pose a problem for ground-based electro-optical space surveillance sensors. The close separations between the objects subtend angles comparable to the size of turbulence (seeing) cells of Earth’s atmosphere. Speckle interferometry using a crossspectrum approach was explored as a means to overcome atmospheric turbulence to enable measurement of relative positions of on-orbit servicing satellites without the use of adaptive optics and to enable unambiguous positioning of the secondary satellite. A test of this approach using collocated geostationary satellites, acting as on-orbit servicing proxies, found that cross-spectrum measurements can obtain in-track and cross-track relative position precisions better than 100mwhen the satellites’ apparent angular separations were less than 5 arcseconds. Simulations indicate that the radial position estimates requires 3 h of observation data in order to converge and points to a need for longer observation periods to estimate relative orbits. Brightness differences between the objects did not pose a significant observational limitation as brightnesses of mprimary  10.2,  0.3 and mprimary  9.1,  1.5 were speckled successfully with relative position estimates obtained.
speckle interferometry;formation flight;EMCCD;ground based optical
Report Number
DRDC-RDDC-2016-P048 — External Literature
Date of publication
01 May 2016
Number of Pages
Electronic Document(PDF)

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