Resonance-enhanced multiphoton-ionization spectra are presented of the d (1)Pi(g)<--<--b (1)Sigma(g)(+)(1,0) transition of O-2, the b(v=0) state generated both by photolysis of O-3 in the Huggins bands and also by direct excitation of single J levels in an optical-optical double-resonance (OODR) experiment. The ozone-photolysis-derived spectra reveal a preferential formation of b(v=0) fragments with high J, the rotational distributions exhibiting significant dependence on the photolysis wavelength. Rotational analyses of the OODR and ozone-photolysis-derived spectra indicate that the d(v=1) Rydberg state is multiply perturbed by successive vibrational levels of the parallel to(1)Pi(g) valence state. The OODR technique allows the first full resolution of the low-J levels of d(v=1) and the high-J levels favored by the ozone-photolysis technique are reported here for the first time.