Summary of Residual On-axis Leakage
Scope: manifest indices 14–49, excluding 24–29 (ODC-5241 era; ODC-3611 legacy fields not included).
Each table row is one (ODC weight, calibration variant, reference field) combination, aggregated over all SB_REF observations of that field.
Bandpass calibrated (bpcal) and Bandpass + Leakage on-axis calibrated (lcal) variants are shown in separate tables.
Plot badges on the Reference field column link to per-ODC and all-ODC footprint heatmaps (see legend below).
SB_REF media (Stokes/pol.degree MP4, combined-beams PNG, beamwise stats, PAF overlay and movie) are accessible
via the drop-down trigger on each SB_REF ID in the Observed SB_REF IDs column.
Column legend
Notation convention: the superscript in parentheses denotes the index (dimension) over which the statistic is computed.
For example, \(\mu^{(s)}\) = median over SB_REF observations \(s\); \(\mu^{(b)}\) = median over beams \(b\).
Subscripts denote the free indices the result depends on.
| Column | Meaning |
| ODC weight | ODC WEIGHTS ID |
| Variant | Bandpass calibrated (bpcal) or Bandpass + Leakage on-axis calibrated (lcal) |
| Reference field | Name (with skyPos) of the field used for calibration |
| n_obs(f) | Number of independent observations for this field (per ODC weight) |
| Observed SB_REF IDs | Links to the leakage statistics card for each individual SB_REF observation |
| μ⁽ᵇ⁾ | Median across beams of \(\mu_{b,f}^{(s)}\) |
| MAD⁽ᵇ⁾ | MAD across beams of \(\mu_{b,f}^{(s)}\) — beam-to-beam spread |
| min⁽ᵇ⁾ | Minimum across beams of \(\mu_{b,f}^{(s)}\) |
| max⁽ᵇ⁾ | Maximum across beams of \(\mu_{b,f}^{(s)}\) |
All statistics are over percentage linear polarisation leakage, \(dL\) (%).
\(dL = 100 \times L/I\), where \(L\) is the linear polarisation intensity and \(I\) is the Stokes I total intensity.
Plot badges on Reference field column:
dL / |dQ|,|dU| (blue) — per-ODC footprint for that row's variant;
dL≈ / |dQ|,|dU|≈ — all-ODC comparison footprint (bpcal + lcal stacked).
dL = residual leakage (dL = √(Q²+U²)/I (%)), faceted by ODC weight and calibration variant.
|dQ|,|dU| = split-circle plots of |Q|/I (top-left) and |U|/I (bottom-right).
Bandpass calibrated
| ODC weight | Variant | Reference field | n_obs(f) | Observed SB_REF IDs | μ⁽ᵇ⁾ | MAD⁽ᵇ⁾ | min⁽ᵇ⁾ | max⁽ᵇ⁾ |
|---|
| 5229 | bpcal | REF_0236-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 2 | | 0.624 | 0.153 | 0.189 | 1.64 |
| 5229 | bpcal | REF_0324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 3 | | 0.737 | 0.327 | 0.252 | 1.885 |
| 5231 | bpcal | REF_0236-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.57 | 0.159 | 0.211 | 1.837 |
| 5231 | bpcal | REF_0324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.746 | 0.26 | 0.233 | 1.87 |
| 5231 | bpcal | REF_0524-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.472 | 0.173 | 0.249 | 2.141 |
| 5231 | bpcal | REF_1212-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.56 | 0.228 | 0.227 | 5.468 |
| 5231 | bpcal | REF_1324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.611 | 0.12 | 0.251 | 1.32 |
| 5241 | bpcal | REF_0236-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 4 | | 0.598 | 0.196 | 0.241 | 1.788 |
| 5241 | bpcal | REF_0324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 4 | | 0.764 | 0.325 | 0.263 | 1.982 |
| 5241 | bpcal | REF_1212-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 4 | | 0.546 | 0.231 | 0.21 | 5.274 |
| 5241 | bpcal | REF_1324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 5 | | 0.57 | 0.098 | 0.269 | 1.43 |
| 5241 | bpcal | REF_1612-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 2 | | 0.848 | 0.233 | 0.271 | 2.735 |
| 5241 | bpcal | REF_2300-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.582 | 0.155 | 0.246 | 2.017 |
| 5259 | bpcal | REF_0236-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.637 | 0.181 | 0.224 | 1.798 |
| 5259 | bpcal | REF_0324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.664 | 0.266 | 0.234 | 2.052 |
| 5259 | bpcal | REF_1124-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 2 | | 0.589 | 0.253 | 0.219 | 2.268 |
| 5259 | bpcal | REF_1324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 2 | | 0.592 | 0.164 | 0.209 | 1.936 |
Bandpass + Leakage (on-axis) calibrated
| ODC weight | Variant | Reference field | n_obs(f) | Observed SB_REF IDs | μ⁽ᵇ⁾ | MAD⁽ᵇ⁾ | min⁽ᵇ⁾ | max⁽ᵇ⁾ |
|---|
| 5229 | lcal | REF_0236-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 2 | | 0.373 | 0.204 | 0.095 | 1.528 |
| 5229 | lcal | REF_0324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 3 | | 0.398 | 0.266 | 0.083 | 1.875 |
| 5231 | lcal | REF_0236-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.364 | 0.168 | 0.093 | 1.71 |
| 5231 | lcal | REF_0324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.526 | 0.306 | 0.113 | 1.858 |
| 5231 | lcal | REF_0524-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.303 | 0.171 | 0.106 | 2.088 |
| 5231 | lcal | REF_1212-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.313 | 0.169 | 0.104 | 5.48 |
| 5231 | lcal | REF_1324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.34 | 0.171 | 0.093 | 1.291 |
| 5241 | lcal | REF_0236-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 4 | | 0.345 | 0.173 | 0.093 | 1.655 |
| 5241 | lcal | REF_0324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 4 | | 0.522 | 0.344 | 0.098 | 1.965 |
| 5241 | lcal | REF_1212-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 4 | | 0.282 | 0.149 | 0.099 | 5.291 |
| 5241 | lcal | REF_1324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 5 | | 0.344 | 0.156 | 0.114 | 1.434 |
| 5241 | lcal | REF_1612-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 2 | | 0.597 | 0.266 | 0.105 | 2.63 |
| 5241 | lcal | REF_2300-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.313 | 0.133 | 0.091 | 1.604 |
| 5259 | lcal | REF_0236-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.479 | 0.253 | 0.086 | 1.677 |
| 5259 | lcal | REF_0324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 1 | | 0.402 | 0.249 | 0.106 | 2.039 |
| 5259 | lcal | REF_1124-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 2 | | 0.393 | 0.24 | 0.094 | 2.161 |
| 5259 | lcal | REF_1324-28 dL |dQ|,|dU| dL≈ |dQ|,|dU|≈ dQ∿ dU∿ | 2 | | 0.363 | 0.176 | 0.088 | 1.88 |
3D Leakage cube (NetCDF4)
The leakage data is stored as a labelled 3-D NetCDF4 cube
with dimensions beam (36) × field (N) × odc (M).
Variables: dL_bpcal, dL_lcal, p90_bpcal, p90_lcal, nsb_bpcal, nsb_lcal.
Open with xarray.open_dataset('leakage_cube.nc') for programmatic slicing, outlier detection, or further analysis.
leakage_cube.nc (109 KB)
Gain Calibration Strategy
Open: Gain Calibration Strategy
— derivation of the bandpass correction factors from 1934−638 measurements.
dQ/dU Correction Factors
Per-beam leakage correction factors derived from 1934−638 observations. All three files open as plain text in a new browser tab.