DDFacet Does Not Update Central Frequency and RESTFRQ in Sub-Band Image Headers

[BANELE-MTHEMBU]

After generating two sub-band images, I ran DDFacet for imaging. However, I noticed that the header information was not updated correctly, specifically the central frequency and RESTFRQ values. Both sub-band images still show a RESTFRQ of 1.28 GHz, which is incorrect for the respective sub-bands. The imaging part went well just one issue related to the header. How can I fix this without manually updating the header myself ??

[mhardcastle]

The only way you can fix this is by updating the header yourself, sorry!

However if you can post an example command to give more details about what you're doing we can see if DDFacet can be made to do the right thing in future.

[BANELE-MTHEMBU]

Thank you for the clarification. This isn’t the first time I’ve encountered this issue. After generating my three sub-band images and running DDFacet for imaging, I again noticed that the header information was not updated correctly. Specifically, the RESTFRQ and Central FRQ values still default to 1.28 GHz for all sub-bands, which is not accurate. The imaging itself completed successfully, but the header remains unchanged, as before.

I’ve since tried to manually update the header after imaging. Just to provide more context, below is the exact command I used for imaging all of my three sub-bands.

singularity exec /idia/software/containers/ddfacet_v0.7.2.sif DDF.py \ --Data-MS cfp2020_1_subband3.ms \ --Data-ColName DATA \ --Data-ChunkHours 1 \ --Data-Sort 1 \ --Predict-InitDicoModel /scratch3/users/banele/oxkat_r/IMAGES/img_cfp2020_1_full_1024ch_J0438-5419.ms_DDFpcal.DicoModel \ --Output-Name /scratch3/users/banele/killms_sol_2/three_subbands/img_cfp2020_1_full_1024ch_J0438-5419.ms_DDFkMS_subband3 \ --Output-Mode Clean \ --Output-Also oenNS \ --Output-Images DdPMmRrIikz \ --Output-Cubes MmRi \ --Image-NPix 10125 \ --Image-Cell 1.1 \ --Facets-DiamMax 0.25 \ --Facets-DiamMin 0.05 \ --Facets-NFacets 4 \ --Facets-PSFOversize 1.5 \ --Facets-Padding 3.0 \ --Weight-Mode Briggs \ --Weight-Robust 0.0 \ --Comp-GridDecorr 0.01 \ --Comp-DegridDecorr 0.01 \ --Comp-Sparsification 0 \ --Parallel-NCPU 16 \ --Cache-Reset 0 \ --Cache-Dir . \ --Cache-HMP 1 \ --Beam-Model None \ --Freq-NBand 4 \ --Freq-NDegridBand 4 \ --DDESolutions-DDSols /scratch3/users/banele/killms_sol_2/cfp2020_1_subband3.ms/killMS.killms_band3_solutions.sols.npz \ --DDESolutions-DDModeGrid AP \ --DDESolutions-DDModeDeGrid AP \ --Deconv-Gain 0.15 \ --Deconv-FluxThreshold 3e-06 \ --Deconv-CycleFactor 0 \ --Deconv-RMSFactor 3.0 \ --Deconv-Mode Hogbom \ --Deconv-PeakFactor 0.1 \ --Deconv-MaxMajorIter 0 \ --Deconv-MaxMinorIter 1000 \ --Hogbom-PolyFitOrder 4 \ --Mask-Auto 0 \ --Mask-External /scratch3/users/banele/oxkat_r/IMAGES/img_cfp2020_1_full_1024ch_J0438-5419.ms_pcalmask-MFS-image.mask1.zoom10125.fits \ --Misc-ConserveMemory 1 \ --Log-Memory 1 \ --Log-Boring 1 \ --Selection-ChanStart 0 \ --Selection-ChanEnd 142 \ --Selection-ChanStep 1

I hope this gives more insight into what I’m doing, in case it’s helpful for improving DDFacet in the future.

[bennahugo]

Hi. Can you print out the ::SPECTRAL_WINDOW subtable of the three datasets - I presume they live in separate physical datasets on disk?