Draw a labelled ray diagram of an astronomical telescope in the near point adjustment position. A giant refraction telescope at an observatory has an objective lens of focal length $15\mathrm{m}$ and an eyepiece of focal length $1.0\mathrm{cm}$. If this telescope is used to view the moon, find the diameter of the image of the moon formed by the objective lens. The diameter of the moon is $3.48\times {10}^6\mathrm{m}$, and the radius of lunar orbit is $3.8\times {10}^8\mathrm{m}$.