Speaker
Description
In this paper, we presents a technical assessment of an observational event capturing the lunar occultation of Sgr A* on 12th of March 2026, by using the Italian Primalucelab SPIDER 300A radio telescope in Hong Kong. Within the four hours observation window, a 2D On-The-Fly (OTF) mapping technique was sequentially applied to generate a time series of 12 radio images at the 21cm wavelength. The raw spatial data revealed a continuous 3% to 4% increase in global intensity across the sequential maps rather than a distinct focal dip, indicating a strong instrumental thermal drift and atmospheric background variation over the extended scanning period. We analyze the limitations of small aperture radio mapping under intense urban radio frequency interference (RFI) and outline a future image processing pipeline. That is the specifically background subtraction and relative radio photometry. It will be the basic requirements to extract faint transient signals from drifting baselines in urban radio astronomy.