The first high-resolution electron density maps of the low-latitude D- and E-region ionosphere in the Pacific sector acquired with ALTAIR UHF measurements are presented. The electron density data were collected in connection with a rocket based common volume experiment described by Friedrich et al. (2006). The observed phenomena in the density maps include E-region density layers of tidal origin, shorter lived layers with small vertical scales, and lower E-region electron density enhancement in response to enhanced X-ray flux. Copyright 2006 by the American Geophysical Union.