Phys.org  December 27, 2021 An international team of researchers (China, Canada, USA – MIT, Sweden) show that the geometry required for the International Meridian Circle Program global observation system leads to a deployment of instruments in priority along the 120°E–60°W great meridian circle, which will cover in an optimal way both the dominant geographic and geomagnetic latitude variations, possibly complemented by a second Great Circle along the 30°E–150°W meridians to capture longitude variations. Then, starting from the Chinese Meridian Project network and using it as a template, they give a preliminary description of the instruments to be integrated and deployed […]