System model of an image stabilization system

Subpixel real-time jitter detection algorithm and implementation for polarimetric and helioseismic imager

“…As the f t−o is 30 Hz, the f image ≥ 300 fps. Also the upper delay limit for τ CL to reach the desired damping is 3.5 ms. 11 The major contributions to the delay come from the photon budget, readout of the NOIS1SM100A 38 sensor and the interface bit rate (100 Mbps). The CTC has been optimized to allow the transfer of the pixel values at the same rate as they are sampled.…”

“…Since the SO platform is expected to have a stability ðσÞ of 1 pixel, using the AE3 • σ rule (or 6 • σ), a correlation matrix (CT x;y ) of 7 × 7 elements is calculated by Eq. (11). Hence, to compute the SSD in parallel, 49 multipliers (DSP modules) are used at once: E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 1 1 ; 3 2 6 ; 7 5 2 CT x;y ¼ SSDðx; yÞ ∀ x; y ∈ ð−3;3Þ; (11) where x and y are the correlation matrix indices.…”

“…(11). Hence, to compute the SSD in parallel, 49 multipliers (DSP modules) are used at once: E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 1 1 ; 3 2 6 ; 7 5 2 CT x;y ¼ SSDðx; yÞ ∀ x; y ∈ ð−3;3Þ; (11) where x and y are the correlation matrix indices. The algorithm has to take into account two aspects.…”

“…The ISS 11 has to compensate the S/C jitter in real time (RT), while the SIs are being taken. No roll correction is needed, as the S/C's attitude control system meets the SO/PHI requirements.…”

“…This implies a postprocessing time of 0.6 ms. The upper delay limit for PHI to reach the desired damping is 3.5 ms, 11 while the number of pixels of the image can be 6 times bigger (128 × 128). The proposed algorithm minimizes the postprocessing time, using a pixel-wise strategy.…”