View source for White noise levels for high cadence scan at elevation of 40 degrees

=== Summary ===

In this posting provides noise levels for a [[Modulated_scan_high_cadence_LAT |high cadence scan strategy]] at an elevation of 40 degrees, with az=[20,160] and az=[200, 340], and with a base scan rate of 1 deg/s.

=== Depth maps ===

Depth maps for 10 days of observation provided by Reijo for 1 optics tube for the LF bands, and 1/8th of an optics tube for the MF and HF bands can currently be found here 
 <nowiki>/global/cscratch1/sd/keskital/s4sim/reference_tool/out_v1/00000000</nowiki>

The simulations provide noise covariance matrices for TQU (as well as inverse covariance matrices, hits maps, and one realization). Here we show the depth maps in temperature

[[File:depth_maps_el_40.png|900px]]


The underlying NETs and detector counts can be found in this [https://docs.google.com/spreadsheets/d/1X0x8wYhjHdI_WPjhgbtyVlVQrX86tTgxgqEUhan2Hxg/edit spreadsheet]. The efficiency of the simulations is 91.7%, with 8.3% spent in turn-arounds. The noise levels shown below are scaled to an overall efficiency of 25% (to match the estimates made by the NTT) and observing time of 7 years. In addition, the map level depths presented below assume a yield of 80%, correlation factors and number of tubes taken from the same [https://docs.google.com/spreadsheets/d/1X0x8wYhjHdI_WPjhgbtyVlVQrX86tTgxgqEUhan2Hxg/edit spreadsheet].

===Noise characteristics for elevation of 40 degrees===


{| class="wikitable" style="text-align: right; margin-left: 51px;"
 !Frequency band !!  LF !! MF !! HF
|-
|Sky fraction (in %)||68.6 || 67.8 || 67.0
|-
|Effective sky fraction for signal (in %)|| 61.6 || 63.7 || 63.8
|-
|Effective sky fraction for noise (in %)|| 66.0 || 66.2 || 65.9
|}


{| class="wikitable" style="text-align: right; margin-left: 51px;"
 ! Frequency (GHz) !!   27 !!  39 !!  93 !! 145 !! 225 !! 278 
|-
|white noise level TT (uK-arcmin)||21.34 || 11.67 || 1.89 || 2.09 || 6.90 || 16.88
|-
|ell knee TT||415||391||1932||3917||6740||6792
|-
|1/f exponent TT (uK-arcmin)||-3.5||-3.5||-3.5||-3.5||-3.5||-3.5
|-
|white noise level E/B (uK-arcmin)||30.23 || 16.53 || 2.68 || 2.96 || 9.78 || 23.93
|-
|ell knee E/B||700||700||700||700||700||700
|-
|1/f exponent E/B (uK-arcmin)||-1.4||-1.4||-1.4||-1.4||-1.4||-1.4
|}

The simulations provide information both about white noise levels and the atmospheric 1/f contribution. For MF and HF, the behavior in polarization is similar to the previous estimates with lknee between 500 and 700 although with a somewhat shallower rise (between -1.06 to -1.2). For LF the simulations suggest significantly lower atmospheric noise. Since this is preliminary, the table uses the noise model inferred from the WAFTT work.