Speckle Suppression Budgets: Raw Contrast, Angular Differential Imaging Gain and Residual Floors

This study computes a detection budget for a clearly bounded question: Starting from the raw halo contrast delivered by adaptive optics and a coronagraph, how much do reference subtraction, angular differential imaging and spectral differential imaging each contribute, and where does the suppression chain stop? Raw halo contrast at 0.4 arcseconds is taken as 1e-06; reference subtraction brings the floor to 1e-07. The full chain reaches 3.33e-09 at 0.4 arcseconds and 3.33e-09 at 0.8 arcseconds. At 0.1 arcseconds the residual is only 2.05e-08, because the angular gain there is just 3.2. All values are computed from published anchor values and stated assumptions by a deposited script; the study is simulated and computed throughout, not measured. Speckle suppression chains deliver Jupiter-class contrasts at moderate separations but saturate two orders of magnitude short of terrestrial reflected-light requirements.