Wish List - Star Atlas and platesolve data base

Cameras, telescopes, focusers and other hardware
Post Reply
Dunmunro
Posts: 225
Joined: 10 Jan 2019, 01:11

Wish List - Star Atlas and platesolve data base

Post by Dunmunro » 15 Mar 2019, 20:34

Currently the camera frame is shown in the Star Atlas. Would it be possible to show the guide camera and imaging camera frames simultaneously in the Star Atlas?

I intend to use an OAG in the future and it would be very handy to have the both the guide camera and imaging camera frames visible to aid in placing the guidecamera onto a suitable guidestar. I was thinking this could be done automatically by platesolving guidecamera and imaging camera images and then creating a master frame showing the outline of both camera frames in the Star Atlas.

On the same topic, I am concerned that the current stellar database for platesolving might not be large enough to plate solve the smaller OAG camera field = 9.6 x 7.2 arc minutes. This issue might not be a problem if the imaging camera frame has the guide camera frame attached to it so that the imaging camera's larger field can be used for platesolving whilst still aiding in the location guidestars for the guidecamera.

fabdev
Posts: 461
Joined: 03 Dec 2018, 21:43

Re: Wish List - Star Atlas and platesolve data base

Post by fabdev » 16 Mar 2019, 17:44

Hello, adding figures to the Atlas can be done easily.
As you wrote, platesolving the guider may not work, and in any case it will not help to reach the guide star, since the guide camera will be moved blindly by hand.
By the way: since an OAG just rotates around the main field, maybe the best information to know is what stars can be actually reached rotating the OAG.
Two circles like this can be useful: In this example the only star is in the South-"West" direction, the AOG could be rotated there by hand with ease, for example placing 8 tags on the OAG as reference.
(I'm assuming that you cannot afford to move the main field too much).

A rectangle for the guider could drawn too, but this would be in a "fixed" position relatively to the main camera, just like in dual chips camera. For OAGs it could show the "zero rotation" position.

Dunmunro
Posts: 225
Joined: 10 Jan 2019, 01:11

Re: Wish List - Star Atlas and platesolve data base

Post by Dunmunro » 16 Mar 2019, 18:49

fabdev wrote:
16 Mar 2019, 17:44
Hello, adding figures to the Atlas can be done easily.
As you wrote, platesolving the guider may not work, and in any case it will not help to reach the guide star, since the guide camera will be moved blindly by hand.
By the way: since an OAG just rotates around the main field, maybe the best information to know is what stars can be actually reached rotating the OAG.
Two circles like this can be useful:
Circles.jpg
In this example the only star is in the South-"West" direction, the AOG could be rotated there by hand with ease, for example placing 8 tags on the OAG as reference.
(I'm assuming that you cannot afford to move the main field too much).

A rectangle for the guider could drawn too, but this would be in a "fixed" position relatively to the main camera, just like in dual chips camera. For OAGs it could show the "zero rotation" position.
Thanks.

I think the ideal would be a frame that has a rectangle showing current imaging camera and OAG camera locations and two circles to show potential OAG locations. It would be great if plate solving the guider frame would work since then AA7 could create the frames automatically and precisely. This could also be done via the Astrometry interface, on a one time basis and then stored for furture use as I always keep the USNO A2 star catalogue on the local machine for Star Atlas use.

I have several thoughts on OAG use. My first is that modern guide cameras are very sensitive and my mounts have very low periodic error, so i might be able to guide on very faint stars via long integrations times (up to the guide camera limit of 9sec, IIRC) and this will help minimize the need for OAG camera rotation. 2ndly, I might acquire a guide camera with a larger sensor, again to aid in guide star acquisition without having to rotate the OAG, since my plan is for remote operation (from nearby) as much as possible.


BTW here is my (Serpens) Observatory at work:

https://photos.app.goo.gl/k2HU2bNeYjGMqLhd8

fabdev
Posts: 461
Joined: 03 Dec 2018, 21:43

Re: Wish List - Star Atlas and platesolve data base

Post by fabdev » 16 Mar 2019, 22:09

Indeed, rotating by hand an OAG just to find a guide star is not productive in 2019.

Another user preferred to autoguide with an exposure time of 6 seconds and this proved sufficient in all situations. For this task an experimental feature was added last year: "master dark frame correction for the guider".
The user provides an high quality (full frame) master dark frame of the guider, then during autoguide the current subframe is corrected with the corresponding subframe of the master dark.

About platesolve on a small field of 9'x7', I estimated that it's possible (only) in 60-70% of all cases.

Post Reply