Rabbi Losh has taught the concept of Hilchos Kidush Hachodesh in simple terms using diagrams and globes in a shiur filmed on 18 Tishrei 5748. The video was captured by R’ Sholom Ber Goldstein, who made it available to viewers through JEM. This shiur predates the technologically advanced shiurim for Kidush Hachodesh that we have today.
In the video, Rabbi Losh discusses the Rambam’s astronomy and begins in English before transitioning to Hebrew after a few minutes. If you are interested in watching the video and gaining insights into Hilchos Kidush Hachodesh, click on the link provided.