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Table 2

Overview of wide-field imaging parameters (upper panel) and SPAM parameters (lower panel).

Field diametera 6.8°
Pixel size 4″
Weightingb robust 0.5
Wide-field imagingcd polyhedron (facet-based),
multi-frequency synthesis
Number of facets 199
Facet diameter 0.57°
Facet separation 0.47°
Deconvolutione Cotton-Schwab CLEAN
CLEAN box threshold 5   σ
CLEAN depth 2   σ
Restoring beam 26″ × 22″ (PA 78°)

SPAMf calibration cycles 2
Peeled sourcesg 24
Layer heights (and weights) 100 km (0.25)
200 km (0.50)
400 km (0.25)
Parameter γ (h) 5/3
Model parameters 20
Model fit phase rmsg 19.2° ± 3.0°
Peeling corrections applied yes
Reference catalogi NVSS



We map more than twice the HPBW diameter to allow for deconvolution of nearby bright sources.


Specified for the final (second) calibration cycle only.


Power-law slope of the assumed phase structure function.

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