open-gamma-ray-astro / gamma-astro-data-formats

Data formats for gamma-ray astronomy
https://gamma-astro-data-formats.readthedocs.io
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Explain about EVENTS, GTI and POINTING #127

Closed cdeil closed 5 years ago

cdeil commented 5 years ago

I noticed that we have no information really about EVENTS and GTI and POINTING, and the POINTING is located under EVENTS, where really it doesn't have much to do with EVENTS, but rather is part of "observation" information, or what is sometimes called "tech3" in CTA.

I did not go the step to introduce an "IACT obs" top-level folder and move POINTING there now. Instead, I left it in the "events" folder, but did add a few explanatory sentences about EVENTS, GTI and POINTING. I did also add a recommendation (not a requirement) that EVENTS should be chronologically ordered (will be discussed in #107). And, following other parts of the spec like the EVENTS, made the ALT / AZ optional columns, but required that earth location header keys are given, so that ALT / AZ can be computed from position, time and RA / DEC (same as for EVENTS). POINTING is clearly labeled as very preliminary and not yet in use for IACT DL3 data.