Optimal speckle imaging of extended space objects-results from field data

Speckle imaging techniques have been shown to mitigate atmospheric resolution limits, allowing near-diffraction-limited images to be reconstructed. Few images of extended objects reconstructed using these techniques have been published, and most of these results are for relatively bright objects. In this paper, we present image reconstructions of an orbiting Molniya spacecraft from data collected using a 2.3 meter ground-based telescope. The apparent brightness of the satellite was 15th visual magnitude. Power spectrum and bispectrum speckle imaging techniques are used prior to image reconstruction in order to ameliorate atmospheric blurring. Optimal weighted least squares estimation methods are used to estimate the Fourier spectrum from the power spectrum and the bispectrum. We demonstrate that these optimal methods produce superior image quality as compared to images created using conventional speckle imaging methods.