NIKA January 20th, 2014 / S1
Back to list of day to day logbook of observations
2014-01-21
- Cryostat Temperature: 150mK (regulated, RMS ripple 0.03mK).
- Arrays status tonight: 128 pixels 2mm - 1Hz noise; 196 pixels 1mm 3-5Hz noise
Modulation frequency: 8kHz 1mm, 5kHz 2mm
Opacity is measured with the new taumeter at 225 GHz
Nasmyth offsets : 0, 0
Set pointing : 0, 0
Set Focus : -2.40 mm
Preliminary remark:
- We are afraid that the minimal background is actually not the best radio alignment, indeed if the NIKA pupil is misaligned such that it sees the sky next to M2 it's possible that the background is lower than seeing only M2 (the other hypothesis with the pupil misalignment is that it sees the edge of M1 diffraction the 300K from the ground, so increase the background on the array). Only way to know now is to look at a source (Uranus) with M5 on the "best laser (alignment) position", then look at the source with M5 on the "minimal background" position and compare the beams: the stronger and narrower beam is the one with the best illumination of the telescope pupil.
Quick description of the session: Test an upgrade of data acquisition. Try to find if the radio alignment was correct. Choose reference detector. Pointing and Focus on Ref det. Pointing session.
Scan |
UT |
Source |
Command |
Az |
El |
Pointing X, Y, Focus |
Tau225 |
Comment |
176 |
16h45 |
Uranus |
Track |
180 |
56 |
0,0,-2.4 |
0.28 |
Track30 |
177 |
16h55 |
Uranus |
Track |
180 |
56 |
0,0,-2.4 |
0.28 |
Track60 |
178 |
16h57 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.28 |
Noelvin data |
179 |
16h59 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.28 |
Noelvin data |
180 |
17h00 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.28 |
|
181 |
17h03 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.3 |
source close to array edge |
182 |
17h05 |
Uranus |
Cross |
180 |
56 |
0,0,-2.4 |
0.3 |
M5 on "best laser position" (see preliminary remark above) no source |
183 |
17h07 |
Uranus |
Cross |
190 |
55 |
0,0,-2.4 |
0.3 |
no source (additional problem: sky gets cloudy) |
184 |
17h07 |
Uranus |
Cross |
190 |
55 |
0,0,-2.4 |
0.3 |
back to M5 on "minimal background position" => no source |
185 |
17h19 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.3 |
offsets 2.9 40.8 Nasmyth to get source at array center => no source |
186 |
17h19 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.3 |
offsets 0 0 Nasmyth => see source |
187 |
17h28 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.4 |
offsets -2.9 -40.8 Nasmyth to get source at array center => see source but not at center |
188 |
17h28 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.4 |
|
189 |
17h28 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.4 |
offsets 0 -40.8 Nasmyth to get source at array center => see source |
190 |
17h28 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.4 |
offsets 0 40.8 Nasmyth to get source at array center => see source |
191 |
17h28 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.4 |
offsets 40.8 0 Nasmyth to get source at array center => see source |
192 |
17h28 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.4 |
offsets -40.8 0 Nasmyth to get source at array center => see source |
193 |
17h28 |
Uranus |
Cross |
193 |
55 |
0,0,-2.4 |
0.4 |
|
194 |
17h43 |
Uranus |
Cross |
205 |
53 |
0,0,-2.4 |
0.5 |
offsets -40.8 -20 Nasmyth to get source at array center => see source |
195 |
17h43 |
Uranus |
Cross |
205 |
53 |
0,0,-2.4 |
0.5 |
offsets -60 -20 Nasmyth to get source at array center => source near center: det 430 & 32 |
196 |
17h43 |
Uranus |
Cross |
205 |
53 |
32.4,-36,-2.4 |
0.5 |
same Nasmyth (source near center: det 430 & 32) but with pointing correction |
197 |
17h52 |
Uranus |
Cross |
205 |
53 |
32.4,-36,-2.4 |
0.5 |
|
198 |
17h52 |
Uranus |
PointLiss |
205 |
53 |
32.4,-36,-2.4 |
0.5 |
try with Lissajou => source at edge of the array !? |
199 |
17h52 |
Uranus |
PointLiss |
205 |
53 |
32.4,-36,-2.4 |
0.5 |
|
200 |
18h00 |
Uranus |
PointLiss |
205 |
53 |
32.4,-36,-2.4 |
0.5 |
offsets 0 0 Nasmyth => no source |
201 |
18h00 |
Uranus |
PointLiss |
211 |
51 |
0,0,-2.4 |
0.5 |
|
202 |
18h00 |
Uranus |
PointLiss |
211 |
51 |
0,0,-2.4 |
0.5 |
offsets -60 -20 Nasmyth => source at center (as we expected for scan 198) !? We don't understand |
203 |
18h00 |
Uranus |
Cross |
211 |
51 |
0,0,-2.4 |
0.5 |
no source |
204 |
18h12 |
Uranus |
PointLiss |
215 |
50 |
0,0,-2.4 |
0.5 |
|
205 |
18h12 |
Uranus |
PointLiss |
215 |
50 |
0,0,-2.4 |
0.5 |
|
206 |
18h16 |
Uranus |
PointLiss |
217 |
50 |
0,0,-2.4 |
0.5 |
offsets -100 -20 Nasmyth (try offsets in all direction to understand) |
207 |
18h12 |
Uranus |
PointLiss |
217 |
50 |
0,0,-2.4 |
0.5 |
offsets -20 -20 Nasmyth |
208 |
18h12 |
Uranus |
PointLiss |
217 |
50 |
0,0,-2.4 |
0.5 |
offsets -60 20 Nasmyth |
209 |
18h12 |
Uranus |
PointLiss |
217 |
50 |
0,0,-2.4 |
0.5 |
offsets -60 -60 Nasmyth |
210 |
18h12 |
Uranus |
PointLiss |
220 |
49 |
0,0,-2.4 |
0.6 |
offsets -60 -20 Nasmyth (back to what should be the source at the center of the array) |
211 |
18h12 |
Uranus |
Cross |
220 |
49 |
0,0,-2.4 |
0.6 |
|
212 |
18h28 |
Uranus |
PointLiss |
221 |
48 |
0,0,-2.4 |
0.7 |
offsets -50 -20 Nasmyth (back to what should be the source at the center of the array) |
213 |
18h28 |
Uranus |
Cross |
221 |
48 |
0,0,-2.4 |
0.7 |
|
214 |
18h28 |
Uranus |
PointLiss |
221 |
48 |
0,0,-2.4 |
0.7 |
OK now we understand effect of offsets, problems on some previous scans maybe due to bad sky fluctuations |
215 |
18h28 |
Uranus |
Cross |
221 |
48 |
0,0,-2.4 |
0.7 |
|
216 |
18h28 |
Uranus |
PointLiss |
221 |
48 |
0,0,-2.4 |
0.7 |
acumulate stat (we know we are not at best focus, but for pupil illumination test this is not primordial) |
217 |
18h28 |
Uranus |
Cross |
221 |
48 |
0,0,-2.4 |
0.8 |
|
218 |
18h36 |
Uranus |
PointLiss |
226 |
45 |
0,0,-2.4 |
0.8 |
|
219 |
18h36 |
Uranus |
PointLiss |
226 |
45 |
0,0,-2.4 |
0.9 |
Now M5 on "best laser position" => OK: the source has moved as expected |
220 |
18h39 |
Uranus |
Cross |
226 |
48 |
0,0,-2.4 |
0.9 |
Unfortunatelly the sky is really too bad for the crosses: we see nothing => give up crosses for now |
221 |
18h39 |
Uranus |
PointLiss |
226 |
45 |
0,0,-2.4 |
1 |
|
222 |
18h53 |
Uranus |
skydip_up |
230 |
45 |
0,0,-2.4 |
1 |
to measure the tau in a bad sky (while comparing scans at 2 positions of M5) |
223 |
19h00 |
Uranus |
PointLiss |
230 |
45 |
0,0,-2.4 |
1 |
offsets -40 10 Nasmyth (to move the source at the center of the array) |
224 |
19h02 |
Uranus |
PointLiss |
230 |
45 |
0,0,-2.4 |
1 |
very bad tau but atmosphere much more stable (seen on timelines)... no source however |
225 |
19h02 |
Uranus |
PointLiss |
230 |
45 |
0,0,-2.4 |
1 |
|
226 |
19h06 |
Uranus |
PointLiss |
230 |
45 |
0,0,-2.4 |
1 |
WE WERE STILL ON SOURCE DIY_TIP !!! |
227 |
19h06 |
Uranus |
track |
230 |
45 |
0,0,-2.4 |
1 |
|
228 |
19h09 |
Uranus |
PointLiss |
230 |
45 |
0,0,-2.4 |
1 |
Now OK with offsets -40 10 Nasmyth => source at center of array as expected: ouf ! |
229 |
19h11 |
Uranus |
PointLiss |
233 |
42 |
0,0,-2.4 |
1 |
|
230 |
19h12 |
Uranus |
PointLiss |
233 |
42 |
0,0,-2.4 |
1 |
|
231 |
19h12 |
Uranus |
Cross |
233 |
42 |
0,0,-2.4 |
1 |
try a cross though the tau doesn't give hope to see something |
232 |
19h17 |
Uranus |
PointLiss |
234 |
41 |
0,0,-2.4 |
1 |
|
233 |
19h17 |
Uranus |
PointLiss |
234 |
41 |
0,0,-2.4 |
1 |
|