The meridian is an imaginary line that goes from the pole down to the horizon. Once an object that you are tracking with your (German equatorial) mount crosses the meridian, if the mount continues to track the object (without doing a flip), it would eventually hit the base of the mount. To avoid this, the mount needs to do a (180 degrees) meridian flip. In other words the scope needs to point up instead of pointing down once it passes the meridian. Our control software will automatically flip the Paramount ME at the meridian. On most systems you can image several mins past the meridian. Before an automatic flip and reacquiring of guide stars takes place. Your session will then continue.
You will see a message like this in the Status Window:
11:57:08 21:57:08 # Image 3 of 10 Moon Position: 92.8 degrees @ angle 254.0 from imaging target. Moon Alt: 7.93 Azm: 255.87 Illumination: 26.1
11:57:08 21:57:08 ### Next scheduled reservation starts at: Friday, September 13, 2013 7:15:00 PM in 69.3 hour(s) for user: bmoore on 37983.
11:57:08 21:57:08 Target: PK13J020 RA: 21h 11m 02.9s DEC: 04� 03' 00" (J2000) HA: 0 PA: 0 Alt: 54.6 Azm: 4.3
**This is where the file name is chosen for the image. Since the mount was still east at this point, the label reflects that.
11:57:08 21:57:08 Imaging to T17-ajenkins-PK13J020-20130910-215708-Luminance-BIN2-E-060-003.fit
11:57:08 21:57:08 Flip check: Time Needed=-60s Hour Angle=-46s Gem West=F Time to Flip=-38s Is Gem Going West=F Flip=no.
11:57:08 21:57:08 (taking 60 sec. exposure, Luminance filter, binning = 2)
11:58:15 21:58:15 Image File Saved to T17-ajenkins-PK13J020-20130910-215708-Luminance-BIN2-E-060-003.fit
11:58:17 21:58:17 Skipped Preview Image
**This is where the system checks for the flip, which was needed which you can see at Flip=YES:
11:58:17 21:58:17 Flip check: Time Needed=-60s Hour Angle=23s Gem West=F Time to Flip=32s Is Gem Going West=T Flip=YES.
You will also notice that in your image names, you will see the following change as well: