  Gravitational waves from sub-solar mass primordial black holes could be
detected in LIGO, Virgo and KAGRA data. Here, we apply a method originally
designed to look for rapidly spinning-down neutron stars, the generalized
frequency-Hough transform, to search for planetary-mass primordial black holes
using data from the first half of the third observing run of advanced LIGO. In
this companion paper to arXiv:2402.19468, in which the main results of our
search are presented, we delve into the details of the search methodology, the
choices we have made regarding the parameter space to explore, the follow-up
procedure we use to confirm or reject possible candidates returned in our
search, and a comparison of our analytic procedure of generating upper limits
to those obtained through injections.
