“…Fortunately, several stable RTP filters are available for low magnetic latitudes (Guo et al, 2013;Hansen & Pawlowski, 1989;Li & Oldenburg, 2001;Mendonça & Silva, 1993;Stewart, 2019;Zhang et al, 2014). Zhang et al (2018) and Ribeiro (2020) solved the numerical instability of RTP processing at magnetic equator by using a stable RTP operator in cross-correlation method.…”