RE: Survey Strategy

["Creager, Robert S" <CreagRS@LOUISVILLE.STORTEK.COM>]

Yup.  This is exactly what I'm doing.  I'm also keeping track of the last
time a picture was taken so I can move during the DARK exposure
(transitioning from object to dark) without executing a clearing scan.

I may work on moving RA and DEC at the same time to increase the possible
distances traversed during the transfer.  Otherwise, moving DEC on ROB takes
most of the available time (45.5 (steps/second) / 120 (steps/degree) * (45s
- 20s clamp open/close) = 5.7 degrees).  I need to open the DEC clamp on ROB
400 steps to not bind with the brake, providing a much smoother DEC
movement.
Moving both mechs at the same time will just entail breaking down the DEC
move into multiple moves which coincide with the desired RA move timing.
Easy ;-)

Unless I am mistaken though (in reference to Arne's tech note), the minimum
exposure is around 20-30 seconds, the time it takes to download the data
from the memory card.

> -----Original Message-----
> From: Tom Droege [mailto:tdroege2@earthlink.net]
> Sent: October 04, 2002 1:18 PM
> To: Creager, Robert S; tass@listserv.wwa.com
> Subject: RE: Survey Strategy
> 
> 1) close the shutter
> 2) start the scan
> 3) look to see what you want to do next
> 4) move the telescope to the new position
> 5) start the RA drive going to get rid of backlash
> 6) test for the block done
> 7) note the time and open the shutter to start taking the next image
> 8) go to 1)
> 
> Note that with this sequence, or something like it, one is dead for
> exactly
> 46 seconds between frames.  You should always be able to get ready for the
> next frame in this time.  I do not think that you will be able to see any
> effects from moving motors, etc., in the data, but one should check.