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--- imagerteleconnotes20170919 [2017/09/19 13:55] – kyoung
+++ imagerteleconnotes20170919 [2017/09/27 11:11] (current) – kyoung
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 ====== Telecon 20170919 ======
-Attending: \\
 __Agenda:__
   * Focal Plane Model + Noise (Young) {{:pico_fdm_noise_model_status_20170919.pdf|Slides}}
-  * Optics (Wen, Hills)
+  * {{::coma-correction.pptx|Optics: coma correction (Hills)}}
+  * Optics {{::cross_dragone_sep192017.pdf|Cross Dragone Designing}}(Wen)
+  * {{::cbmpol_trade_interfaces.xlsx|Trade matrix}}
 __Notes:__
+Attending: Al, Brian, Roger, Jeff F., Julian, Shaul, Karl, Qi
+Noise and focal plane (Karl Young)
+  * baseline polarization weight calculated. full sky, 4 yrs.
+    * accounting for DLFOV area on focal plane, not laying out wafers.
+    * correction from last week's pixel count.  Now 6k (open), 10.5k (crossed)
+  * Set edge taper to lowest band of MC pixel
+    * pixel size up by 1.4x, N pixels down by 2, sensitivity down by 1.4
+    * stop under-illuminated for higher bands in pixel
+      * this means a loss of resolution compared to optimum for 1.4 m mirror
+    * **General question to group**  What near sidelobe level is acceptable? -20 dB? -40 dB?  This sets the acceptable edge tapers.
+  * Comparison with Roger's TDM noise
+    * loading agrees
+    * photon noise off by 17% at low frequency, probably Bose noise difference, investigating
+    * phonon noise off by 30%, likely difference in safety factor 2 (Roger) vs 2.5 (Karl)
+    * NETs, Karl higher by 30% at 20 GHz, higher by 5% at 800 GHz
+      * due to where phonon noise is more significant.
+Coma corrected optics (Richard Hills, presented by Shaul)
+  * Dragone calculated equations to elimate coma in Dragone type systems
+  * Richard implented this via computer optimization in Zemax for the open and crossed systems
+  * DLFOV increases at all frequencies by,
+    * ~3x diameter at 900 GHz
+    * ~1.1x diameter at 25 GHz
+Redesigning crossed dragone (Qi Wen)
+  * Goal: avoid 'clipping' sidelobe and direct focal plane view of sky
+  * Requires:
+    * increase f/# to move focal plane away from secondary
+    * reduce FOV, allows focal plane to move away from secondary
+  * Current example has now direct view, but 2 types of 3 reflection sidelobes.
+  * Design work continuing.
+Trade-off matrix (Brian)
+  * trade-offs vs baselines of various aspects
+  * goal is to show connections between systems
+  * work in progress:
+    * add spin and precession rates
+    * is orbit still variable?  Or fixed to L2?

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