Pulse Guiding in The SkyX

[E_ri_k]

Hi, I am a new to The SkyX, I haven't actually installed it yet, but Greg B gave me a quick demo on his computer the other week. I was using Maxim DL previously, and pulse guiding my G11 with it, because my Lodestar had a dodgy ST-4 connection......Anyway it was great. I have looked a little on Google, but I cant find too much info.

Is it possible to pulse guide in The SkyX, and eliminate the need the guide cable?

I found it is possible to connect and run Maxim DL and The SkyX together, but it means having 2 applications running at the same time which would be a litle annoying.

Erik

[gregbradley]

Hi Erik,

I just cleared up this question myself. Software Bisque uses a proprietary method of autoguding command called Direct Guide. It works directly with the mount drive controller and it gets a confirmation back from it so its more accurate. It means also no extra guide cable. Pulse Guide I think is a similar approach but perhaps not exactly the same for other brands.

Note that Direct Guide minimum and maximum moves are measured in arc seconds and so is calibration but pulse guide and relay guide are measured in seconds (duration of speed up/slow down) and so min/max moves are much smaller numbers.

So min/max move for direct guide is worked out using CCDware autoguiding calculator For my setup it was minimum .5 and maximum 2.0.

If the seeing were good you might make corrections more aggressive and min move a smaller value.
Settings I last used and it was going beautifully were:

3 second guide exposures
1 second delay (I didn't always use this and I think it depends on how much weight is on the mount to allow for momentum).
aggressiveness 3 or 4
backlash zero

When doing calibration I added a 1 second delay otherwise after it slews the resulting guide star is elongated badly.

I had polar alignment very exact before this using Tpoint and several models.

TPoint. Download the New Astronomy Press Ron Wodaski CCD calcualator its very useful. Work out the image scale for your setup ( focal length and pixel size).

Once you have Tpoint setup and its doing plate solves correctly (make sure image scale is accurate). I used 5 second exposures at 2x2 binning with a 9 micron pixelled camera giving an image scale of 3.32.

Get your mount at the right angle for your latitude. Do the rough polar alignment as per the manual. This only takes a few minutes.
Then start a TPoint calibration. Perhaps 15 points. Do the adjustments per the Polar Alignment report. Do another Tpoint full calibration (it erases the first model). Repeat and you should be a lot closer.

Now I would do a larger one if you think you are close maybe 100 points (it does 3 a minute so its only 35 minutes or so). Do the Super Model button. Click the accurate polar alignment button lower down on the Polar Alignment report. Manually adjust the centred star per the instructions. Now you should be super close.

You could do yet another full large model - 300 points and do accurate polar alignment again and this will take only a minor adjustment and that's about as good as its going to get. Autoguiding should now give really low errors and you get nice round stars.

I would use the existing PEC I put in the mount as it worked really well and I used PemPro.

That is under Bisque TCS in the telescope tab. Click on PEC and get. Its stored in the mount.

Greg.