天图投影上的圆

• On the atioff projection map, how to draw a circle (e.g. telescope field of view)? suppose, telescope pointed at (Ra0,Dec0), FOV is a circle with radius R0

1. Change the coordinate system from celestial to the designed coordinate (pole at Ra0,Dec0).
2. Then the circle in the new coordinate system is simply DecP=90-R0
3. change the new coordinate system back to celestial

• 文件:Change cor.pro.txt