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| imagerteleconnotes20171031 [2017/10/31 13:57] – hanany | imagerteleconnotes20171031 [2017/11/07 13:46] (current) – kyoung | ||
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| ====== Telecon 20171031 ====== | ====== Telecon 20171031 ====== | ||
| - | Attending: | + | Attending: |
| __Agenda: | __Agenda: | ||
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| === Notes === | === Notes === | ||
| - | Atd: | + | Higher throughput, lower noise optics and focal plane (Young) |
| + | * correcting optics for coma | ||
| + | * get to 7350 bolos or 15030 bolos (depends on pixel size and edge taper) | ||
| + | * pixel size set by middle band or lowest band. | ||
| + | * middle band gives smaller pixels, worse spillover efficiency. | ||
| + | * Brendon: far sidelobes a systematic concern. | ||
| + | * alternative pixel band structure (slide 5) | ||
| + | * reduces spillover variance within a pixel. | ||
| + | * NET penalty, narrow bands to avoid overlap. | ||
| + | * Jamie: not clear that overlap is a problem. | ||
| + | * Jamie: what does single band pixels look like? Fewer broad bands. | ||
| + | * **A/I** Karl to check. | ||
| + | * Technical or science issues with alternative band structure? | ||
| + | * nothing from people currently. | ||
| + | |||
| + | Scan optimization + simulations (Kris presentation by Shaul) | ||
| + | * single detector, alpha = 22, beta = 75 | ||
| + | * was at 3 rpm spin, now 1 rpm spin, varying precessions | ||
| + | * suggests precession < 10 hrs | ||
| + | * alpha, beta dictate large scale features | ||
| + | * Zoom on N_obs panel, shows striping at < 12 hours. | ||
| + | * Jamie: pixelization effects? are there gaps in scan on small scales? | ||
| + | * rings on sky in 1 day, full maps per detector in 6 months. | ||
| + | * Jamie: thinks no resource problems with fast precession. | ||
| + | * Still need check with Amy. | ||
| + | * Aside: Brendon, adding reaction wheels to systematics. Can have vibrations. | ||
| + | * Jamie: Can have ' | ||
| + | |||
| + | Systematics, | ||
| + | * How to combine systematics and imager work? | ||
| + | * Brendon: Systematics WG has list of systematics and risk level for each. Goal to prioritize systematics. | ||
| + | * table on wiki. SRF rating of 5 is worst. | ||
| + | * Most worried: | ||
| + | * combination of we know least about it, drives instrument design, or limited past experiments | ||
| + | * others also, but more confident they can be dealt with. | ||
| + | * WG has found simulation capability, e.g. TOAST. | ||
| + | * Shaul: TOAST was plan to simulate noise + scan. | ||
| + | * systematics can be added here as well. Work done for LITEBird, CORE. | ||
| + | * example: adding far sidelobes is straightforward | ||
| + | * T-->P leakage sim by CORE. | ||
| + | * QuickPol looks at main beam mismatch. | ||
| + | * bandpass mismatch (Ranajoy) | ||
| + | * in CORE systematics paper. | ||
| + | * Joy: many simulations give you large values for systematics, | ||
| + | * Jamie: Good approach. Don't worry about everything, priortize based on Planck, CORE, LITEBird work. | ||
| + | * Shaul: Goal, get inputs systematics group needs. | ||
| + | * far sidelobes, working on input via Brad and Amy | ||
| + | * polarization calibration inaccuracies: | ||
| + | * no solid calibration plan yet, so key errors not yet known or quantified. (not ready for simulation) | ||
| + | * gain stability: ability to continuously measure gain. 4 yr calibration on dipole is great. But can't see dipole constantly (scan strategy input). CORE folks have worked on this, Tomassi volunteered but not until January. | ||
| + | * Joy: need instrument inputs on gain stabiliy (bath, temperature variation, etc.) | ||
| + | * can simulate observation, | ||
| + | * Jamie: can this simulate deprojection? | ||
| + | * not clear this capability exists. | ||
| + | * Brendon, Shaul, Joy to meet this week and coordinate on systematics plan. | ||