Technical definition of sunset


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I have a quick question on the technical definition of sunset - the course links off to an almanac but I was hoping it would be simpler - i.e. as soon as the lowest point of the sun hits the horizon that's sunset and it's evening civil twilight for 30 minutes (and the reverse for morning). 

And if you google it and get a time, do you know if that's the same time as used by FAA? 

Thanks!

Brian

P.S. - great course BTW, learning a lot and it's easy to get through. 

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In my opinion, provided that you gave Google an accurate location, I think that time would be sufficient.  But, if you want to be precise (or run some examples to check the accuracy of Google), you can go the the US Naval Observatory website.  There you can find a VERY precise calculator for this info based an exact lat/lon positions for anywhere in the world.

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As with all things around FAA, stay on the conservative side. I highly recommend taking a moment and check the local sunset and civil twilight time through the air almanac. http://aa.usno.navy.mil/data/docs/RS_OneDay.php

Problems arise if you eyeball when the sun hits the horizon. It gets tricky when you have obstructions like buildings, haze, clouds, and hilly/mountain terrain. What will you count as the horizon? When the sun is below the mountain top or when it passes the lowest valley point that's just a few degrees over?

To really cover your butt, you can note the sunset time in your flight log. In case of an investigation, this will demonstration you are a responsible pilot and you took precaution in your pre-flight planning. It is one more step, but totally worth the time.

Best, Kam

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Great Link! I can actually use that compared to the almanac. And it looks like google is pretty spot on.

As for recording it, that's my plan - as I log flights, put on their sunset, take-off time, and landing time. 

Speaking of flight logs - I've been relying on the DJI Go log as I've been learning (and 'landing' in a cactus by mistake :-) ). But I'm getting pretty comfortable flying and getting close to objects and doing inspections and so on. So I was planning on making something a little more official for logging time. What do you use? Just PnP? Or an App? Or do you just DJI Go's logs?

Thanks!

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On 12/1/2016 at 8:55 PM, Beacon Sky Survey said:

To really cover your butt, you can note the sunset time in your flight log. In case of an investigation, this will demonstration you are a responsible pilot and you took precaution in your pre-flight planning. It is one more step, but totally worth the time.

REALLY like this idea.

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