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--- imagerteleconnotes20180221 [2018/02/21 17:40] – wenxx181
+++ imagerteleconnotes20180221 [2018/02/22 11:34] (current) – wenxx181
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       * color is in log scale, red is much more dense than blue
       * color scales in slow and fast are not same; the maxium in 48 hrs is a factor of ~4 compared to 7 hrs
-      * Kris's conclusion: short precession is better
+      * Kris's conclusion: short (fast) precession is better
+    * Shaul: 1 arcmin in 3 sigma in single spin rate is based on fast precession
+    * Kris: many motions of PICO are much faster than Planck, we need to be careful. Someone studing WMAP pagers is a good thing to do.
+    * Shaul: we need to be careful, star tracker; In optical astronomy, they don’t scan fast, so it’s trivial for them.
+  * Telescope I+T (Tomo）
+    * pg24
+      * reminder, introduction about what Tomo talks today
+      * fully integrated test when it’s cold
+      * optics only; tests one can possibly imagine
+    * pg28
+      * purpose: mirror shape
+      * two spacial scales: large ,small scales
+        * Large scals: you cannot probe smaller than the space between markers
+        * Short scales: very small scales
+      * A combination of both scales; blue table
+      * “Cold” means some cold temperature, not necessary the mission temp
+      * Minimal tests for PICO: Photogrammetry and Interferometry; certainly can be done
+      * CMM: surface, not sure if there is facility big enough for PICO mirror
+      * Shaul: mirror vendor, whatever lab who puts the instrument together; whoever provides mirrors, they would CMM warm; CMM is part of the cost buying the mirror; I & T is beyond vendor level.
+      * Tomo: for space mission, it’s common you repeat measurements even vendors have done so.
+      * Brian: normally,  vendors verify, we would not check again.
+      * Tomo: different models, e.g. ground model, flight model; you can do tests in first few models, then you trust (vendors).
+    * pg29
+      * Tomo: partly a comment, partly a question
+        * after the characterization, what information are we using?
+      * pre-flight: sub and full level tests; outputs: performance verification and mirror shapes
+      * inflight: beam calibration; slide shows beam profile from Planck
+      * post-flight: if with precise beam, with pre-flight information, systematics; if beam not precise, we need GRASP model, and correct for it.
+      * What did Planck use to get beam? What are the key information?
+      * Kris: LFI used Grasp model; HFI used planet measurements; signal-to-noise is the reason. LFI is much more noisy. Absolute size of beam matters. pre-flight + inflight consideration.
+      * Beam size is important because couple to focal plane; in part of scanning. Sometimes more reliable on GRASP model.
+      * Tomo: future mission should have tighter requirement for signal-to-noise; does this mean they will be like LFI case?
+      * Kris: Any test before flight is valuable.
+      * Shaul: not clear what Planck did was used and useful in terms of tests.
+      * Kris: not sure if there is a short path compared to Planck.
+    *Pg30
+      * Tomo: it’s very important to characterize feed beam. For Planck, corrugated horns are classic and thus did not need more attention; PICO could use something else.

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