VHF Beam Characteristics · Each holography raster provided a quasi-regular grid of curves. Model...
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VHF Beam Characteristics D. A. Mitchell, L. J. Greenhill, C. Carilli, R. A. Perley July, 2006 1 Overview This report is a summary of investigations into the beam characteristics of the the new VHF receiver system for the VLA EOR extension program. The data were collected from the setup on antennas 8, 17 and 26. It is seen that the beams show comparible circular cross-sections and stability to the current P-band system. It should be noted that the beams are at times quite poorly characterized as 2-D Gaussian, so when comparing beam widths and other features one should also refer to the images at the end of this report to inspect the quality of the fits. 2 Observations Table 1 gives an overview of VHF observations used to characterise the system. Dipoles were attached to antennas 8, 17 and 26, one of which was used as the holography reference antenna. Two types of VHF dipoles were used: (1) a “short” dipole with a 10 cm stand-off from the P-band dipole and (2) a “long dipole” with a 15.6 cm stand-off. (Long and short dipoles differ in length by only 0.640 cm. The prototype dipoles whose performance has already been reported used the same stand-off as the present long dipoles, and their lengths were 1.5 cm shorter.) Each holography raster comprises an oversampled grid of points (between 25 and 33 square) with an angular spacing ∼ λ/3D or 1.2 ◦ . Some distortion in the regularity of the grid occurred at high elevations, but this was taken into account in our analysis. Four ten-second integrationswere vector averaged for each raster point. Observation Date VHF Receiver Type Central Frequency Source Ref Ant 30 November 2005 Long dipoles 195.4 MHz Tau A 26 13 November 2005 Short dipoles 195.3 MHz Cas A 26 28 December 2005 Short dipoles 184.4 MHz, IF 1 Tau A 08 28 December 2005 Short dipoles 194.0 MHz, IF 2 Tau A 08 Table 1: VHF Observation Parameters. 3 Analysis After standard calibration and holography processing, each set of data was vector averaged and fitted to a two dimensional Gaussian distribution. The Levenberg-Marquardt method of χ 2 opti- mization was used to fit the center of the beams (down to about 40%) for six parameters of the natural logarithm of the Gaussian defined in (1); the amplitude ln(A); the beam center (x 0 ,y 0 ), where coordinates x = sin -1 (l) and y = sin -1 (m); the width (σ x , σ y ); and the measure of diagonal 1
Transcript of VHF Beam Characteristics · Each holography raster provided a quasi-regular grid of curves. Model...
VHF Beam Characteristics
D. A. Mitchell, L. J. Greenhill, C. Carilli, R. A. Perley
July, 2006
1 Overview
This report is a summary of investigations into the beam characteristics of the the new VHFreceiver system for the VLA EOR extension program. The data were collected from the setupon antennas 8, 17 and 26. It is seen that the beams show comparible circular cross-sections andstability to the current P-band system. It should be noted that the beams are at times quite poorlycharacterized as 2-D Gaussian, so when comparing beam widths and other features one should alsorefer to the images at the end of this report to inspect the quality of the fits.
2 Observations
Table 1 gives an overview of VHF observations used to characterise the system. Dipoles wereattached to antennas 8, 17 and 26, one of which was used as the holography reference antenna.
Two types of VHF dipoles were used: (1) a “short” dipole with a 10 cm stand-off from the P-banddipole and (2) a “long dipole” with a 15.6 cm stand-off. (Long and short dipoles differ in lengthby only 0.640 cm. The prototype dipoles whose performance has already been reported used thesame stand-off as the present long dipoles, and their lengths were 1.5 cm shorter.)
Each holography raster comprises an oversampled grid of points (between 25 and 33 square) withan angular spacing ∼ λ/3D or 1.2◦. Some distortion in the regularity of the grid occurred athigh elevations, but this was taken into account in our analysis. Four ten-second integrations werevector averaged for each raster point.
Observation Date VHF Receiver Type Central Frequency Source Ref Ant
30 November 2005 Long dipoles 195.4 MHz Tau A 2613 November 2005 Short dipoles 195.3 MHz Cas A 2628 December 2005 Short dipoles 184.4 MHz, IF 1 Tau A 0828 December 2005 Short dipoles 194.0 MHz, IF 2 Tau A 08
Table 1: VHF Observation Parameters.
3 Analysis
After standard calibration and holography processing, each set of data was vector averaged andfitted to a two dimensional Gaussian distribution. The Levenberg-Marquardt method of χ2 opti-mization was used to fit the center of the beams (down to about 40%) for six parameters of thenatural logarithm of the Gaussian defined in (1); the amplitude ln(A); the beam center (x0, y0),where coordinates x = sin−1(l) and y = sin−1(m); the width (σx, σy); and the measure of diagonal
1
distortion (ρ). Each holography raster provided a quasi-regular grid of curves. Model beams werefit directly to the data, while regridding and interpolation were applied to obtain contour plots.
The parameters of the fit are defined in (1), where x = sin−1(l), y = sin−1(m), and ρ is a measureof any diagonal distortion in the beam. The spread along each axis of the beam is given by σx
and σy, with the full width at half maximum (FWHM) given by 2σx
√
−2(1− ρ2) ln(1/2) and
2σy
√
−2(1− ρ2) ln(1/2) along the l and m axes respectively.
beam(x, y) = exp
{
−
1
2(1− ρ2)
(
(x − x0)2
σ2x
+(y − y0)
2
σ2y
−
2ρ(x − x0)(y − y0)
σxσy
)}
(1)
The eigenvectors of the fitted beams give the primary and secondary axes (the widest and narrowestbeam cuts). Images of these fits are shown at cfa-www.harvard.edu/~dmitchell/dawn. Table 2gives a summary of the spread of these parameters for the observations in table 1.
Images of these fits are also shown at cfa-www.harvard.edu/~dmitchell/dawn. Table 2 gives asummary of the spread of these parameters for the observations in table 1. A Gaussian distributionis only approximate for most of these data, so the widths given are only indicative. Additionally,data from the last two observations, at the bottom of the table, contained interference, and sotheir interpretation should be approached with care. In particular, antenna 17 at 184.4 MHz (bothpolarizations), and 194.0 MHz (LL polarization) has quite poor quality fits.
Observation Antenna Note FWHM◦
l FWHM◦
m FWHM◦
max FWHM◦
min ρLong dipoles 08 LL minimum 5.2 5.4 6.4 4.6 −0.30195.4 MHz 08 RR minimum 5.4 5.2 6.1 4.7 +0.26λ/D = 3.52◦ 17 LL minimum 4.9 5.8 5.9 4.9 −0.06
17 RR minimum 5.0 5.7 5.7 4.9 −0.02Short dipoles 08 LL minimum 4.3 4.3 4.7 4.0 −0.15195.3 MHz 08 RR minimum 4.3 4.1 4.5 3.9 +0.12λ/D = 3.52◦ 17 LL 4.0 4.4 4.4 4.0 +0.00
17 RR 4.1 4.2 4.4 3.9 +0.12Short dipoles 17 LL bad fit 4.0 4.7 4.8 4.0 +0.11194.0 MHz 17 RR 4.0 3.9 4.1 3.8 −0.06λ/D = 3.54◦ 26 LL RFI 4.5 5.0 5.9 4.0 −0.34
26 RR RFI 4.5 4.5 4.7 4.3 +0.10Short dipoles 17 LL bad fit 5.1 4.5 5.1 4.5 +0.02184.4 MHz 17 RR bad fit 5.6 4.9 5.6 4.8 +0.09λ/D = 3.73◦ 26 LL 4.4 5.0 5.0 4.4 +0.06
26 RR 4.8 5.1 5.1 4.8 +0.01
Table 2: VHF Summary Table
To aid in the contouring of the beams, the real and imaginary components of each data set wereindividually interpolated onto a regular grid using a cubic Shepard (scattered) interpolation (seeSCILAB documentation at www.scilab.org). The grid spacing was set to 1.2 degrees, approxi-mately one raster step. The -3dB contour of each fit is also shown.
Figures 1 amd 2 show holography contour plots for LL and RR polarizations respectively. Thelower images from December were contaminated by RFI and are not used in the above analysis.Figures 4 through 10 show the beam contours with beam various beam cuts. For a complete setof images, and logarithmic scaling, see http://cfa-www.harvard.edu/~dmitchell/dawn.
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a. November Observationsantenna 08: short diople, 195.3 MHzrho = −0.30, position angle = 41.1 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 195.3 MHzrho = −0.06, position angle = 10.5 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 08: long diople, 195.4 MHzrho = −0.15, position angle = 44.6 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: long diople, 195.4 MHzrho = 0.00, position angle = −0.3 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
b. December Observationsantenna 26: short diople, 184.4 MHzrho = 0.08, position angle = −16.7 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 184.4 MHzrho = −0.03, position angle = 80.8 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 26: short diople, 194.0 MHzrho = −0.33, position angle = 34.7 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 194.0 MHzrho = −0.04, position angle = 4.5 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
Figure 1: VHF holography contours (LCP polarization).
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a. November Observationsantenna 08: short diople, 195.3 MHzrho = 0.26, position angle = −49.9 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 195.3 MHzrho = −0.02, position angle = 4.2 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 08: long diople, 195.4 MHzrho = 0.12, position angle = −54.3 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: long diople, 195.4 MHzrho = 0.12, position angle = −39.1 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
b. December Observationsantenna 26: short diople, 184.4 MHzrho = 0.11, position angle = −20.0 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 184.4 MHzrho = 0.07, position angle = −42.7 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 26: short diople, 194.0 MHzrho = −0.07, position angle = 16.2 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 194.0 MHzrho = −0.02, position angle = 77.4 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
Figure 2: VHF holography contours (RCP polarization).
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a. LCP polarization Observations
antenna 17: short diople, 195.3 MHzrho = −0.06, position angle = 10.5 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: long diople, 195.4 MHzrho = 0.00, position angle = −0.3 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 184.4 MHzrho = −0.03, position angle = 80.8 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 194.0 MHzrho = −0.04, position angle = 4.5 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
b. RCP polarization Observations
antenna 17: short diople, 195.3 MHzrho = −0.02, position angle = 4.2 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: long diople, 195.4 MHzrho = 0.12, position angle = −39.1 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 184.4 MHzrho = 0.07, position angle = −42.7 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
antenna 17: short diople, 194.0 MHzrho = −0.02, position angle = 77.4 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
Figure 3: VHF holography contours for antenna 17.
5
a. LL Polarization
rho = −0.06, position angle = 10.5 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{−0.11,2.48} deg, FWHM=5.82
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.05,2.10} deg, FWHM=4.93
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.49} deg, FWHM=5.86
Fit: N{0.00,2.09} deg, FWHM=4.90
b. RR Polarization
rho = −0.02, position angle = 4.2 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{−0.09,2.43} deg, FWHM=5.73
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.22,2.10} deg, FWHM=4.95
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.43} deg, FWHM=5.73
Fit: N{0.00,2.10} deg, FWHM=4.94
Figure 4: 13 Nov 2005, IF 1 (195.4 MHz), Antenna 17, Reference 26.
6
a. LL Polarization
rho = 0.00, position angle = −0.3 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.15,1.86} deg, FWHM=4.39
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.10,1.69} deg, FWHM=3.98
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,1.86} deg, FWHM=4.39
Fit: N{0.00,1.69} deg, FWHM=3.98
b. RR Polarization
rho = 0.12, position angle = −39.1 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.01,1.79} deg, FWHM=4.19
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.10,1.75} deg, FWHM=4.09
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,1.89} deg, FWHM=4.41
Fit: N{0.00,1.67} deg, FWHM=3.91
Figure 5: 30 Nov 2005, IF 1 (195.3 MHz), Antenna 17, Reference 26.
7
a. LL Polarization
rho = 0.11, position angle = −17.1 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.34,2.01} deg, FWHM=4.72
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.26,1.71} deg, FWHM=4.01
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.06} deg, FWHM=4.81
Fit: N{0.00,1.69} deg, FWHM=3.95
b. RR Polarization
rho = −0.06, position angle = 50.2 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.03,1.67} deg, FWHM=3.93
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.10,1.69} deg, FWHM=3.97
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,1.73} deg, FWHM=4.07
Fit: N{0.00,1.63} deg, FWHM=3.84
Figure 6: 28 Dec 2005, IF 2 (194.0 MHz), Antenna 17, Reference 08.
8
a. LL Polarization
rho = 0.02, position angle = −85.7 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.50,1.90} deg, FWHM=4.48
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.03,2.15} deg, FWHM=5.07
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.16} deg, FWHM=5.07
Fit: N{0.00,1.90} deg, FWHM=4.47
b. RR Polarization
rho = 0.09, position angle = −72.2 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.00,2.08} deg, FWHM=4.87
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.14,2.37} deg, FWHM=5.55
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.41} deg, FWHM=5.64
Fit: N{0.00,2.05} deg, FWHM=4.81
Figure 7: 28 Dec 2005, IF 1 (184.4 MHz), Antenna 17, Reference 08.
9
a. LL Polarization
rho = −0.30, position angle = 41.1 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{−0.23,2.41} deg, FWHM=5.41
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.04,2.31} deg, FWHM=5.19
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.83} deg, FWHM=6.36
Fit: N{0.00,2.07} deg, FWHM=4.64
b. RR Polarization
rho = 0.26, position angle = −49.9 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.07,2.26} deg, FWHM=5.15
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.08,2.37} deg, FWHM=5.39
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.69} deg, FWHM=6.12
Fit: N{0.00,2.06} deg, FWHM=4.69
Figure 8: 13 Nov 2005, IF 1 (195.4 MHz), Antenna 08, Reference 26.
10
a. LL Polarization
rho = −0.15, position angle = 44.6 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{−0.07,1.86} deg, FWHM=4.32
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.04,1.85} deg, FWHM=4.32
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.01} deg, FWHM=4.68
Fit: N{0.00,1.73} deg, FWHM=4.03
b. RR Polarization
rho = 0.12, position angle = −54.3 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.22,1.75} deg, FWHM=4.09
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.04,1.82} deg, FWHM=4.26
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,1.91} deg, FWHM=4.47
Fit: N{0.00,1.68} deg, FWHM=3.92
Figure 9: 30 Nov 2005, IF 1 (195.3 MHz), Antenna 08, Reference 26.
11
a. LL Polarization
rho = −0.34, position angle = 36.3 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.10,2.25} deg, FWHM=4.98
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.10,2.02} deg, FWHM=4.48
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.64} deg, FWHM=5.86
Fit: N{0.00,1.83} deg, FWHM=4.05
b. RR Polarization
rho = 0.10, position angle = −41.5 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.18,1.92} deg, FWHM=4.50
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.18,1.90} deg, FWHM=4.45
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.02} deg, FWHM=4.72
Fit: N{0.00,1.82} deg, FWHM=4.26
Figure 10: 28 Dec 2005, IF 2 (194.0 MHz), Antenna 26, Reference 208.
12
a. LL Polarization
rho = 0.06, position angle = −13.4 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.34,2.11} deg, FWHM=4.95
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.05,1.88} deg, FWHM=4.41
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.12} deg, FWHM=4.99
Fit: N{0.00,1.87} deg, FWHM=4.38
b. RR Polarization
rho = 0.01, position angle = −4.2 deg
asin(l)
asin(m)
−20 −15 −10 −5 0 5 10 15 20−20
−15
−10
−5
0
5
10
15
20
0.1%0.5%1%5%10%25%50%
l=0 Cutasin(m)degrees
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4−20
−15
−10
−5
0
5
10
15
20Fit: N{0.19,2.17} deg, FWHM=5.11
m=0 Cut
asin(l)degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{−0.17,2.04} deg, FWHM=4.80
Major & Minor Axis Cuts
degrees−20 −15 −10 −5 0 5 10 15 20
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4Fit: N{0.00,2.17} deg, FWHM=5.11
Fit: N{0.00,2.04} deg, FWHM=4.80
Figure 11: 28 Dec 2005, IF 1 (184.4 MHz), Antenna 26, Reference 08.
13
