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ewan douglas

@douglase.bsky.social
324 followers 887 following 36 posts

Professing on space telescopes of all sizes; Tucson, AZ.

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ewan douglas @douglase.bsky.social · 21/07/2025
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.
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ewan douglas @douglase.bsky.social · 18/09/2024
Bluesky now has over 10 million users, and I was #500,463!
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ewan douglas @douglase.bsky.social · 01/12/2023
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.
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ewan douglas @douglase.bsky.social · 14/10/2023
Same! from Tucson
Partial lunar eclipse with iphone through eclipse viewing glasses
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