Exploration by the UNG is based on Zentraedi star-charts produced by the Protoculture. Due to galactic drift and constant motion in the galaxy, the charts are risky if used exclusively. The UNG is practicing a more conservative manner of 'checking' the validity of the charts while exploring the local arm of the Milky Way Galaxy and beyond.
The majority of the initial ship commanders and politicians of the UNG come from the Earth and Earth's maritime. Due to that, a large amount of the initial thinking of, and actual exploration by the initial commanders and politicians was performed on a relatively 2-D horizontal pattern. As time passes and more VF/Space pilots and classically trained Zentraedi rise the ranks to command positions and policy making, the 2-D horizontal pattern is gradually shifting to a 3-D pattern.
As of 2050, the UNG has explored more along the ecliptic of the Sol system than 'above' and 'below' it. The sector that has been explored the most is Sector 1, followed by Sector 2, Sector 1a and Sector 1Alpha; with the nearest 100 light years to Sol having had the most exploration and the most colonization. The area beyond has seen much less exploration, and colonization based on a mixture of following Zentraedi star charts for habitable planets and luck.