Drift Alignment

Further work has been carried out to substitute Drift Alignment for Polar Alignment.

On 20201109, the mount ship CG5 was drift aligned with 120s exposures in a DARV routine of one iteration. The whole process took 2 hours: adjusting altitude is okay, but azimuth is not - the mount ship has a north peg that suffered damage in battles fought long ago, and as a consequence now the bolts that adjust azimuth behave erratically. Still, images of a subsequent jump (with camera removal and reattachment) compared well both with images of the same region made for a test some time ago, and with images from an actual jump, judging by star roundness.

On 20201110, the mount ship alignment was checked by another drift alignment procedure. Few adjustments were made. On the one hand, alignment had been preserved; on the other hand, we lacked precision. A subsequent test jump revealed that 120s exposures already suffered from trailing stars.

In short, we can drift align the mount ship CG5 one day, and make a jump another day. However, we must limit exposures to less than 120s.

The less than 120s limitation, however, may also come from the 3 arcsec pixel plate of our imaging equipment and the lack of autoguiding. The alignment can also be improved, if we take longer exposures and only stop upong achieving "straight lines".

At any rate, this is a step forward in our path towards the Astronomican.

Image from day 20201109. While it looks almost perfect, az the first time, az and alt both the second, were good, but not that good.

Image comparison, crops at 300% magnification. Images were converted using the exact same settings except for a different flat field image and exposure compensation. In the same fashion, crops belong in the exact same region of the frame, plus/minus a few pixels.