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Testing SkyTrack continuous tracking with the Mach2 #Mach2GTO

David Johnson
 

As mentioned in another topic, SkyTrack now has continuous-tracking capability with compatible ASCOM mounts, including the Mach2. Here’s a YouTube video showing some indoor testing I did. It shows the software screen and mount behavior in an inset.  Note the automatic meridian flip. It does take a few moments to reacquire the target after the flip. I’m looking forward to trying it out for real as soon as the clouds cooperate. Thanks, Brent, for the exciting new capability.
David Johnson
 

Here’s a time-lapse version.
Brent Boshart
 

Hi David,

I noticed in your video that your timing offset is set to 10 seconds. Make sure you set that back to 0 when you get out to try it (provided your computer time is accurate).   Here is a video on using those controls to center the satellite in your view.  https://www.youtube.com/watch?v=1HImmMpJk1c

Brent 
Daniel Marcus
 

HI Brent
do we need to use apcc in conjuction with the APV2 ascom driver? or will it work using the APV2 ascom driver alone to get it to track the satellites without using leap frog?- we are using a AP1200 mount. Have a purchased copy but have not had clear skies to use it yet. Tried leap frog but needed to set the parameters larger and use a guide scope to acquire the target -did not help that we were fighting the clouds that night as well. 
Dan Marcus

From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Brent Boshart <bboshart@...>
Sent: Thursday, October 14, 2021 9:52 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Testing SkyTrack continuous tracking with the Mach2 #Mach2GTO
 
Hi David,

I noticed in your video that your timing offset is set to 10 seconds. Make sure you set that back to 0 when you get out to try it (provided your computer time is accurate).   Here is a video on using those controls to center the satellite in your view.  https://www.youtube.com/watch?v=1HImmMpJk1c

Brent 

David Johnson
 

Thanks.  Will do.  Can you explain the T+Epoch parameter?  I’ve noticed that’s it’s sometimes red, which I assume is bad. 
Brent Boshart
 
Edited

Hi Dan,
For optimum satellite tracking the software requires two things; good pointing across the whole sky (esp if you want to do high magnification imaging of ISS) and "real time" mount position coordinates. SkyTrack uses a closed loop for tracking, in one instance it calculates the current position of the satellite, the satellite's current angular velocity and queries where the point is currently pointing. It then uses the movexis command to determine a rate based on the satellite velocity and how much it needs to adjust to center the satellite in the FOV.  The issue with some ASCOM drivers is that they may queue the mount's position, for example only querying its position once every second. For normal use this is quite adequate. For satellite tracking it becomes an issue, for example if the object is moving at 2 degrees/second and I query the mount for its position and the data is one second old, I now have random error of a whole 2 degrees.

You can use Skytrack three ways.

1) Connecting with the latest version of APCC Pro and ASCOM gives the best results.  A model with APCC gives excellent pointing. Ray added some excellent features to APCC Pro that allows for "real time"  (modelled) RA/Dec mount queries. In fact one command returns both values often in less than 15ms.

2) The next best method is connecting directly to the mount via a RS232 port (without ASCOM or APCC) using what I call in the software a legacy interface.  This satisfies the "real time" mount position coordinates, however, pointing is less accurate without a model. 

3) The least desirable method is connecting through the ASCOM driver only. There is not modelled pointing and the AP ASCOM driver queues the mount position every second or so.  It will track, but it is not very smooth and it may be difficult to keep the object in the FOV depending on the size of the FOV.

David,
The T+Epoch parameter is the age in days of the orbital elements in the downloaded TLE file. It is best to download a new file each evening before observing.
David Johnson
 

Thanks. I will do that. Thanks again for this big upgrade and thanks also to the Astro-Physics team for the APCC upgrades that make it possible. 
Brian Valente
 

Hi Brent

I purchased a copy - this is really interesting

Do you have any tutorials or guides on how to test the system in preparation for a transit?

ISS transit is coming up for me Sunday




On Fri, Oct 15, 2021 at 8:12 AM Brent Boshart <bboshart@...> wrote:

[Edited Message Follows]

Hi Dan,
For optimum satellite tracking the software requires two things; good pointing across the whole sky (esp if you want to do high magnification imaging of ISS) and "real time" mount position coordinates. SkyTrack uses a closed loop for tracking, in one instance it calculates the current position of the satellite, the satellite's current angular velocity and queries where the point is currently pointing. It then uses the movexis command to determine a rate based on the satellite velocity and how much it needs to adjust to center the satellite in the FOV.  The issue with some ASCOM drivers is that they may queue the mount's position, for example only querying its position once every second. For normal use this is quite adequate. For satellite tracking it becomes an issue, for example if the object is moving at 2 degrees/second and I query the mount for its position and the data is one second old, I now have random error of a whole 2 degrees.

You can use Skytrack three ways.

1) Connecting with the latest version of APCC Pro and ASCOM gives the best results.  A model with APCC gives excellent pointing. Ray added some excellent features to APCC Pro that allows for "real time"  (modelled) RA/Dec mount queries. In fact one command returns both values often in less than 15ms.

2) The next best method is connecting directly to the mount via a RS232 port (without ASCOM or APCC) using what I call in the software a legacy interface.  This satisfies the "real time" mount position coordinates, however, pointing is less accurate without a model. 

3) The least desirable method is connecting through the ASCOM driver only. There is not modelled pointing and the AP ASCOM driver queues the mount position every second or so.  It will track, but it is not very smooth and it may be difficult to keep the object in the FOV depending on the size of the FOV.

David,
The T+Epoch parameter is the age in days of the orbital elements in the downloaded TLE file. It is best to download a new file each evening before observing.



--
Brian 



Brian Valente
Worsel
 

FYI

If you have Norton/Symantec as your virus checker on downloaded files, it will quarantine SkyTrack and flag it as WS.Reputation1.  This is NOT an actual virus.  This is Norton's designation for a file that it cannot find in its database, because of low usage statistics.  Not surprisingly, ST 1.5. is quite new; hence low usage.  Not an real problem, but you will have to restore it from quarantine to install.

Thanks to Brent for his effort on ST!!

Bryan
Brent Boshart
 

I always check my executables before uploading with VirusTotal.  There were no detections against all 67 anti-virus vendors.   https://www.virustotal.com/gui/file/0a36ba4d0811ca1c34e0757dcb82ea89cb646c1b998b971b5a9ecfbb8d5dd94d

False positives are quite frustrating as I usually have to contact a few anti-virus vendors to get them to whitelist my software to prevent the false positives.  Thanks for that note Bryan.
Brent Boshart
 
Edited

Hi Brian,
I am working on documentation for the new release. There is an older video on my website that should help.  First clear night, I will also make a quick start video.
The most common trouble that users have is not setting up the site information correctly. 
David Johnson
 

Latest ISS effort.  Getting better. 
Brent Boshart
 

Hi David,

Nice video!  Are you running APCC and what version number?
David Johnson
 

APCC 1.9.0.11

I’m also using an APPM model, although in this case I was using an older all-sky model since I didn’t have time to do a new model prior to the ISS pass.  It was for the same setup, although I had taken it down and put it back up.  The model was probably pretty good but not perfect. 

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