LOCO EDGES REPORT #106

Summary of Data Analysis: Low-Band 1, Extended Ground Plane

Raul A. Monsalveraul.monsalve@colorado.edu

CASA, University of Colorado BoulderSESE, Arizona State University

August 31, 2017

Here we show results for the analysis of data from the Low-Band 1, Extended Ground Plane instrument.An equivalent report for the Low-Band 1, Original Ground Plane instrument, can be found here:

http://loco.lab.asu.edu/loco-memos/edges_reports/report105.pdf

Nominal choices and calibration settings:

1. Dates: 2016-258 to 2017-95

2. Sun cut: none

3. Moon cut: none

4. Receiver calibration S11 file: s11 calibration low band LNA25degC 2015-09-16-12-30-29 simulator2 long.txt

5. Receiver parameter polynomial terms: Nfit=6, Wfit=5

6. Antenna S11 file: S11 blade low band 2016 243.txt

7. Antenna S11 modeling: 9 polynomial terms after removal of delay

8. Balun loss correction: yes

9. Ground loss correction: yes, 0.5%

10. Beam correction: yes, using beam file newniv rotated to AZ = −7◦, and Haslam sky map scaled to76 MHz using β = −2.5.

1

The results are summarized in the following figures.

The first nine figures (after Figure 1 described below) provide a overview of the data.

• Figure 2: daily residuals to 7-term polynomial over 50-100 MHz, for all days considered. The GHArange is 0-24 hr.

• Figure 3: residuals for 4-hr GHA averages, to 7-term polynomial over 50-100 MHz.

• Figure 4: residuals for 6-hr GHA averages, to 6-term polynomial over 65-95 MHz. Averaging over 6hours produces estimates that are more stable as a function of GHA.

• Figure 5: residuals for 6-hr GHA averages, to 6-term polynomial plus 21-cm signature, over 65-95MHz. The signature center frequency was fixed at 78.5 MHz.

• Figure 6: amplitude of 21-cm signature as a function of GHA for 6-hour averages, in parallel to thetotal sky temperature. The signature center was fixed at 78.5 MHz.

• Figure 7: residuals and model for average over GHA 0-24 hr, to 1) 7-term polynomial over 50-100MHz; 2) 7-term polynomial over 53-97 MHz; 3) 7-term polynomial plus 21-cm signature over 53-97MHz.

• Figure 8: residuals and model for average over GHA 0-24 hr, to 1) 7-term polynomial over 50-100MHz; 2) 7-term polynomial over 60-100 MHz; 3) 7-term polynomial plus 21-cm signature over 60-100 MHz.

• Figure 9: residuals and model for average over GHA 0-24 hr, to 1) 6-term polynomial over 50-100MHz; 2) 6-term polynomial over 60-98 MHz; 3) 6-term polynomial plus 21-cm signature over 60-98MHz.

• Figure 10: residuals and model for average over GHA 6-18 hr, to 1) 6-term polynomial over 50-100MHz; 2) 6-term polynomial over 60-98 MHz; 3) 6-term polynomial plus 21-cm signature over 60-98MHz.

The next five figures show the results for the nominal data average, and compare them with those ob-tained for different data cuts and calibrations. All the cases correspond to data averages over GHA 6-18hr and 60-98 MHz, modeled with a 6-term polynomial plus a 21-cm signature. In these cases, the fre-quency and duration of the 21-cm signature, as well as its amplitude, are found by maximizing the ratioSNR = |a21/σ21|.• Figure 11: residuals and 21-cm signature for three different averages of consecutive subsets of data.

• Figure 12: residuals and 21-cm signature for four different averages: 1) daytime only (ELsun ≥ 0◦),2) nightime only (ELsun < 0◦), 3) Moon up only (ELmoon ≥ 0◦), 4) Moon down only (ELmoon < 0◦).

• Figure 13: residuals and 21-cm signature for two alternative receiver calibrations: 1) cal2015, Nfit=7,Wfit=7, and 2) cal2017, Nfit=7, Wfit=7.

• Figure 14: residuals and 21-cm signature for three alternative antenna S11: 1) 2017-93 (2015 switchparameters), 2) 2016-243 (2017 switch parameters), 3) 2017-93 (2017 switch parameters).

• Figure 15: residuals and 21-cm signature for two alternative corrections: 1) applying no ground losscorrection, and 2) applying no beam correction.

Finally, Table 1 compares the estimates for the different data cuts and calibration alternatives, and Figure1 shows the values.

2

Table 1: Signature amplitude estimates for all the cases considered. In all cases, the GHA range is 6-18 hr.The frequency range is 60-98 MHz and, in addition to the signature, the fit model includes six polynomialterms.

Case Description Amplitude estimate [mK]

0 Nominal 447± 161 1st data subset 428± 272 2st data subset 446± 233 3st data subset 515± 264 Daytime only 493± 345 Nighttime only 452± 176 Moon up only 482± 187 Moon down only 448± 238 recv cal2015, Nfit=7, Wfit=7 571± 219 recv cal2017, Nfit=7, Wfit=7 503± 1710 ant S11 2017-93, switch2015 455± 1611 ant S11 2016-243, switch2017 465± 1612 ant S11 2017-93, switch2017 475± 1713 No ground loss correction 451± 1614 No beam correction 452± 17

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14case number

0

100

200

300

400

500

600

a21 [

mK

]

Figure 1: Signature amplitude for the conditions and cases of Table 1.

3

50 60 70 80 90 100frequency [MHz]

258259260261262263264265266267268269270271273274275276277278279280281282283285287288289290291292293294295296297298302303304

day o

f year

2016 [

1 K

per

div

isio

n]

176 mK

168 mK

181 mK

193 mK

187 mK

177 mK

174 mK

166 mK

199 mK

182 mK

202 mK

175 mK

182 mK

277 mK

185 mK

169 mK

175 mK

171 mK

184 mK

184 mK

165 mK

180 mK

160 mK

271 mK

247 mK

199 mK

189 mK

172 mK

210 mK

191 mK

145 mK

158 mK

175 mK

245 mK

175 mK

176 mK

184 mK

149 mK

157 mK

172 mK

152 mK

50 60 70 80 90 100frequency [MHz]

314315316317318319320321322323324327328329332334336337338339340341342343348350351352354355357358360361362363364365366

12

169 mK

151 mK

162 mK

152 mK

162 mK

175 mK

204 mK

144 mK

177 mK

166 mK

171 mK

175 mK

165 mK

218 mK

160 mK

163 mK

243 mK

224 mK

174 mK

194 mK

261 mK

169 mK

175 mK

204 mK

166 mK

172 mK

168 mK

177 mK

196 mK

196 mK

187 mK

181 mK

151 mK

174 mK

193 mK

296 mK

180 mK

192 mK

167 mK

235 mK

185 mK

50 60 70 80 90 100frequency [MHz]

356789

11121316177778798082838485868788899394

170 mK

183 mK

163 mK

193 mK

151 mK

167 mK

158 mK

226 mK

186 mK

186 mK

137 mK

192 mK

166 mK

164 mK

199 mK

258 mK

209 mK

166 mK

178 mK

183 mK

179 mK

175 mK

214 mK

182 mK

185 mK

Figure 2: Daily residuals to 7-term polynomial over 50-100 MHz, for all days considered. The GHA range is 0-24hr.

50 60 70 80 90 100 110frequency [MHz]

20

16

12

8

4

0

GH

A [

0.5

K p

er

div

isio

n]

RMS: 135 mK

RMS: 83 mK

RMS: 57 mK

RMS: 63 mK

RMS: 102 mK

RMS: 144 mK

7 polynomial terms

Figure 3: Residuals for 4-hr GHA averages, to 7-term polynomial over 50-100 MHz.

4

50 60 70 80 90 100 110frequency [MHz]

18

12

6

0

GH

A [

0.5

K p

er

div

isio

n]

RMS: 46 mK

RMS: 34 mK

RMS: 34 mK

RMS: 41 mK

6 polynomial terms

Figure 4: Residuals for 6-hr GHA averages, to 6-term polynomial over 65-95 MHz.

50 60 70 80 90 100 110frequency [MHz]

18

12

6

0

GH

A [

0.5

K p

er

div

isio

n]

RMS: 37 mK

RMS: 22 mK

RMS: 12 mK

RMS: 26 mK

6 polynomial terms + signature

Figure 5: Residuals for 6-hr GHA averages, to 6-term polynomial plus 21-cm signature, over 65-95 MHz. Thesignature center frequency was fixed at 78.5 MHz.

5

0 6 12 18GHA [hr]

0

200

400

600

800

1000

1200

1400

a21

[m

K]

6 polynomial terms + signature

0

1000

2000

3000

4000

5000

T78.

5 [K

]

Figure 6: Amplitude of 21-cm signature as a function of GHA for 6-hour averages, in parallel to the total skytemperature at 78.5 MHz. The signature center frequency was fixed at 78.5 MHz.

50 60 70 80 90 100 110frequency [MHz]

[0.5

K p

er

div

isio

n]

RMS: 72 mK

RMS: 39 mK

RMS: 23 mK

τ= 7

a21 = 505 +/- 35 mK

νr = 78.2 MHz

∆ν= 19.2 MHz

7 polynomial terms, 0-24 GHA

Figure 7: Residuals for average over 0-24 GHA, to 1) 7-term polynomial over 50-100 MHz (blue); 2) 7-term polyno-mial over 53-97 MHz (green); 3) 7-term polynomial plus 21-cm signature over 53-97 MHz (red). Also shown (cyan)is the best fit 21-cm signature over 53-97 MHz.

6

50 60 70 80 90 100 110frequency [MHz]

[0.5

K p

er

div

isio

n]

RMS: 72 mK

RMS: 29 mK

RMS: 16 mK

τ= 7

a21 = 371 +/- 23 mK

νr = 78.2 MHz

∆ν= 18.0 MHz

7 polynomial terms, 0-24 GHA

Figure 8: Residuals for average over 0-24 GHA, to 1) 7-term polynomial over 50-100 MHz (blue); 2) 7-term poly-nomial over 60-100 MHz (green); 3) 7-term polynomial plus 21-cm signature over 60-100 MHz (red). Also shown(cyan) is the best fit 21-cm signature over 60-100 MHz.

50 60 70 80 90 100 110frequency [MHz]

[0.5

K p

er

div

isio

n]

RMS: 92 mK

RMS: 39 mK

RMS: 19 mK

τ= 7

a21 = 500 +/- 26 mK

νr = 78.0 MHz

∆ν= 19.8 MHz

6 polynomial terms, 0-24 GHA

Figure 9: Residuals for average over 0-24 GHA, to 1) 6-term polynomial over 50-100 MHz (blue); 2) 6-term polyno-mial over 60-98 MHz (green); 3) 6-term polynomial plus 21-cm signature over 60-98 MHz (red). Also shown (cyan)is the best fit 21-cm signature over 60-98 MHz.

7

50 60 70 80 90 100 110frequency [MHz]

[0.5

K p

er

div

isio

n]

RMS: 69 mK

RMS: 32 mK

RMS: 12 mK

τ= 7

a21 = 447 +/- 16 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

6 polynomial terms, 6-18 GHA

Figure 10: Residuals for average over 6-18 GHA, to 1) 6-term polynomial over 50-100 MHz (blue); 2) 6-termpolynomial over 60-98 MHz (green); 3) 6-term polynomial plus 21-cm signature over 60-98 MHz (red). Also shown(cyan) is the best fit 21-cm signature over 60-98 MHz. The signature estimate shown here over 6-18 GHA, is close tothe estimate over 0-24 GHA, shown in the previous figure.

8

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 32 mK

RMS: 12 mK

τ= 7

a21 = 447 +/- 16 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

Total Average

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 34 mK

RMS: 18 mK

τ= 7

a21 = 428 +/- 27 mK

νr = 78.2 MHz

∆ν= 19.8 MHz

Subset 1 of 3

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 34 mK

RMS: 17 mK

τ= 7

a21 = 446 +/- 23 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

Subset 2 of 3

60 70 80 90 100 110frequency [MHz]

[0.2

K p

er

div

isio

n]

RMS: 37 mK

RMS: 17 mK

τ= 7

a21 = 515 +/- 26 mK

νr = 77.8 MHz

∆ν= 18.8 MHz

Subset 3 of 3

Figure 11: Residuals and 21-cm signature for three different averages of consecutive subsets of data. Each subsetcontains one third of the total data. Top panel is the nominal case.

9

60 70 80 90 100 110[0

.2 K

per

div

isio

n]

RMS: 32 mK

RMS: 12 mK

τ= 7

a21 = 447 +/- 16 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

Total Average

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 40 mK

RMS: 24 mK

τ= 7

a21 = 493 +/- 34 mK

νr = 77.8 MHz

∆ν= 19.6 MHz

Daytime Only

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 32 mK

RMS: 13 mK

τ= 7

a21 = 452 +/- 17 mK

νr = 78.0 MHz

∆ν= 19.0 MHz

Nighttime Only

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 35 mK

RMS: 14 mK

τ= 7

a21 = 482 +/- 18 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

Moon Up Only

60 70 80 90 100 110frequency [MHz]

[0.2

K p

er

div

isio

n]

RMS: 33 mK

RMS: 17 mK

τ= 7

a21 = 448 +/- 23 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

Moon Down Only

Figure 12: Residuals and 21-cm signature for four different averages: 1) daytime only (ELsun ≥ 0◦), 2) nightimeonly (ELsun < 0◦), 3) Moon up only (ELmoon ≥ 0◦), 4) Moon down only (ELmoon < 0◦). Top panel is the nominalcase.

10

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 32 mK

RMS: 12 mK

τ= 7

a21 = 447 +/- 16 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

Nominal

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 42 mK

RMS: 17 mK

τ= 7

a21 = 571 +/- 21 mK

νr = 77.8 MHz

∆ν= 19.8 MHz

Calibration 2015, Nfit7 - Wfit7

60 70 80 90 100 110frequency [MHz]

[0.2

K p

er

div

isio

n]

RMS: 36 mK

RMS: 12 mK

τ= 7

a21 = 503 +/- 17 mK

νr = 77.8 MHz

∆ν= 19.6 MHz

Calibration 2017, Nfit7 - Wfit7

Figure 13: Residuals and 21-cm signature for two alternative receiver calibrations: 1) cal2015, Nfit=7, Wfit=7, and2) cal2017, Nfit=7, Wfit=7. Top panel is the nominal case.

11

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 32 mK

RMS: 12 mK

τ= 7

a21 = 447 +/- 16 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

Nominal

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 32 mK

RMS: 11 mK

τ= 7

a21 = 455 +/- 16 mK

νr = 77.8 MHz

∆ν= 19.2 MHz

Antenna S11 2017-93

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 33 mK

RMS: 13 mK

τ= 7

a21 = 465 +/- 16 mK

νr = 78.0 MHz

∆ν= 19.6 MHz

Antenna S11 2016-243, Switch2017

60 70 80 90 100 110frequency [MHz]

[0.2

K p

er

div

isio

n]

RMS: 34 mK

RMS: 13 mK

τ= 7

a21 = 475 +/- 17 mK

νr = 77.8 MHz

∆ν= 19.6 MHz

Antenna S11 2017-93, Switch2017

Figure 14: Residuals and 21-cm signature for three alternative antenna S11: 1) 2017-93 (2015 switch parameters),2) 2016-243 (2017 switch parameters), 3) 2017-93 (2017 switch parameters). Top panel is the nominal case.

12

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 32 mK

RMS: 12 mK

τ= 7

a21 = 447 +/- 16 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

Nominal

60 70 80 90 100 110

[0.2

K p

er

div

isio

n]

RMS: 32 mK

RMS: 12 mK

τ= 7

a21 = 451 +/- 16 mK

νr = 78.0 MHz

∆ν= 19.4 MHz

No Ground Loss Correction

60 70 80 90 100 110frequency [MHz]

[0.2

K p

er

div

isio

n]

RMS: 32 mK

RMS: 13 mK

τ= 7

a21 = 452 +/- 17 mK

νr = 78.2 MHz

∆ν= 19.4 MHz

No Beam Correction

Figure 15: Residuals and 21-cm signature for two alternative corrections: 1) applying no ground loss correction, and2) applying no beam correction. Top panel is the nominal case.

13