Advanced Topics

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Advanced Topics

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Checking pointing accuracy

If you run into problems with pointing or tracking rate accuracy then APPM has a method to check pointing accuracy and repeatability.The procedure is called a 5x Verify, because APPM will make five separate passes using the same set of sky points.

The purpose of the 5x Verify is to determine if the telescope can repeatably point to the same location in the sky. If something is shifting in the optics, or a cable tugging somewhere, this procedure may discover it.

To setup for a 5x Verify, you must enable the following options, which are also identified in the screenshot below:

Recal near the Zenith at start

Precess J2000 to JNow

Verify Pointing Model

Also, the After Complete option must be set to Model 5x and Park.

Lastly, you should reconfigure the number of data points to somewhere between 30-50 points. You don't want to use too many points because each point will get repeated a total of five times. Thus, the more points you use, the longer the procedure will take to complete.



After the 5x Verify completes, you can use the APCC Log Zipper utility to zip up the files. After zipping these can be posted to the ap-goto io groups forum or emailed to Astro-Physics support personal.