Re: Valid Guide Rates for PEC on Gemini Level 4
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UPDATE: The 0.3x and 0.5x from the documentation are incorrect - those are values from the 492 controller, not the Gemini.
Brian
On Mon, Aug 17, 2020 at 2:00 PM Paul Kanevsky < yh@...> wrote: On Mon, Aug 17, 2020 at 04:39 PM, Michael Herman wrote:
So...can someone explain why "autoguide rate" has something to do with PEC??
Hi Michael,
Recording PE data doesn't require knowing the guide rate. Programming PEC data into Gemini - does.
If you are programming PEC manually (using HC or autoguider corrections) then the corrections recorded are relative to the guide rate. If you change the guide rate, the correction rates will also need to be adjusted during PEC playback, and Gemini doesn't do this automatically. So, whatever rate you recorded and programmed PEC is the rate you should use for PEC playback.
When PEC is programmed from the PC, say using PemPro, the corrections are also sent as the number of pulses needed for each of the corrections. This is also based on the guiding speed: if the speed is higher, then fewer pulses are needed, if lower -- more pulses. If the guiding speed is changed after the programming, the number of pulses of corrections will no longer be right and the corrections will be either faster or slower than what was programmed.
Regards,
? ?-Paul
-- Brian?
Brian Valente portfolio
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