The International Galactic Plane Survey is a global effort to map the interstellar matter in our home galaxy, the Milky Way. We plan to chart as much of the Milky Way's 360-degree path around the sky as possible, using radio telescopes to detect interstellar clouds of gas and dust that are often invisible to optical instruments.
The IGPS is not a single project, but rather a collection of radio surveys, each using new techniques to achieve much greater levels of detail than prior efforts. The international character of the IGPS arises naturally from the worldwide community of scientists participating in this effort, and also from the physical need for several facilities at different latitudes around the Earth in order to observe the full circle of the Milky Way, only part of which can be studied from any single location. The picture below shows the locations of the cm-wave arrays used for the IGPS.
The parts of the Milky Way covered by the cm-wave synthesis surveys are shown on the sky chart below, along with relevant constellations.
The Galactic center lies in the direction of Longitude 0, with 180 pointing in the opposite direction, outward from our position in the disk. The CGPS consists of a ``Phase I'' survey, now fully mapped, and a ``Phase II'' survey under funding consideration. The VGPS and SGPS may be similarly extended in the future.
The corresponding areas of the Galactic disk are:
A small white cross indicates the Galactic center, and the Sun's position is marked with a small white circle.