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douglase.bsky.social
ewan douglas
@douglase.bsky.social
270 followers 820 following 26 posts
Professing on space telescopes of all sizes; Tucson, AZ.
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douglase.bsky.social
new 🔭 paper day! Kian Milani and coauthors show how to save computing power and memory with an adjoint model to create high-contrast dark holes with a vortex coronagraph in simulation and reaching <1e-8 contrasts in the lab www.spiedigitallibrary.org/journals/Jou...
Fig. 2: Flowchart illustrates the implementation of aEFC for this work. For each control iteration, the first step is to estimate the focal plane electric field. Here, we assume that pairwise-probing (PWP) is used for this estimation. The next step is to compute the nominal model-based electric field ENOM, which is passed into the optimizer. Within the optimizer is a smaller loop where the forward model is evaluated to compute the cost-function value, then the adjoint model is evaluated to compute the gradient with respect to DM actuators so the optimizer can step the actuators in the direction that minimizes the cost-function. Once the optimizer’s tolerance value or iterations limit is reached, the actuator solution δA is applied to the instrument and the control iteration repeats.
July 21, 2025 at 3:07 PM
douglase.bsky.social
Bluesky now has over 10 million users, and I was #500,463!
September 18, 2024 at 12:01 AM
douglase.bsky.social
new paper day! Led by Postdoc Ramya Anche, this latest peer reviewed work in PASP shows the unique capabilities of the upcoming Nancy Grace Roman Space Telescope's Coronagraph modes to measure polarized light from debris disks around other stars iopscience.iop.org/article/10.1...
Figure 11. The output polarized intensity (Qϕ ), total intensity, polarization fraction, and θ for epsilon Eridani (left-panel) in HLC mode and HR 4796A (right-panel) in SPC mode.
December 1, 2023 at 3:26 PM
douglase.bsky.social
Same! from Tucson
Partial lunar eclipse with iphone through eclipse viewing glasses
October 14, 2023 at 6:56 PM