“I tested PA using an artificial screen that displayed polar stars on a laptop screen about 5 meters away from the telescope“
How it works, and the plate solve works?
Yes, plate solve works with the artificial screen :-).
I had a few weeks ago taken an image of the polar region using my Borg 36ED guide scope (200mm focal length) and the ASI290MM Mini. This image is displayed on a 15" Mac laptop that is placed about 5 meters from the telescope tripod. I have in the past also drawn stars using the Hipparcos catalog; but for this test, I just used a real image. Even though the bright Polaris is a very large bloated disc, plate solve worked anyway.
The reason the laptop and the telescope have to be so close to each other is that the FOV of the telescope has to stay completely within this laptop image, even after the 60 degree rotation. If the telescope sees the edge of the laptop or the surrounding room, then plate solve sees hundreds of fake stars and plate solve would fail.
For my indoor PA test, I told ASIAIR that my latitude is 0 degrees (I am not sure this is needed, but I did it anyway). I mounted the same guide scope (operating as main PA camera) on a Borg alt-az mini half fork. The tripod and the laptop are about the same height from the floor.
Because the image scale is not the same as the sky's tangent plane, I initially told ASIAIR that my focal length is 0, and did a Plate Solve in the Preview screen to find out the equivalent focal length. It came out to be something closer to 120 mm focal length.
With the solved focal length, I went on to the PA screen and performed the initial plate solve. When ASIAIR asked me to rotate the RA axis by 60 degrees, I simply loosened the tube bands of my Borg 36ED scope and rotated the scope itself by 60 degrees. Essentially, I am using the axis of the scope as my "RA axis."
Once done, I simply adjusted the alt and azimuth bolts on the Borg half fork to achieve polar alignment in the next ASIAIR PA screen.
I am retired and have lots of daylight time (and also cloudy nights) to play with telescopes (I ground my first 5" mirror in the early 1960s when I attended high school and lived in Kuala Lumpur :-). So I have created a number of things I could do with telescopes in the daytime. I have also written a program to simulate the star movement on a laptop screen, displaying points of light at a given latitude, and given azimuth and altitude relative to the telescope. I use that to test auto-guiding in the daytime -- I first wrote it many years ago when I was learning PHD2 auto-guiding and was tired of fiddling in the dark being bitten by mosquitos. With a 15" screen at a distance of 10 meters, I can auto-guide for a few minutes before the "guide star" moves outside the laptop screen.
Again, thank you very much to your team for such a fun ASIAIR product. I have used both StellarMate and INDIGO Sky, but they are not as friendly as the tablet-centric paradigm of the ASIAIR. With a small 71 mm refractor and especially together with the small RainbowAstro mount, it is so easy to carry the tripod outdoors and set everything up even when there is only a short time between clouds.
Clear skies,
Chen
(By the way, Jiang xian sheng, my RainbowAstro RST-135 is currently at the Rainbow Robotics Las Vegas office getting its altitude bolt upgraded. So my apologies if I cannot test any ASIAIR Beta that covers the RainbowAstro protocol for a little while (I hope). I understand that you have others who are testing with RainbowAstro already, in any case.)
