From 38b3581f47e4c0c558fc08ac0ecf5d65250e0c22 Mon Sep 17 00:00:00 2001 From: John Wiseman Date: Sat, 14 Dec 2019 00:42:02 -0800 Subject: [PATCH] Listed criteris used for tweeting. --- README.md | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index b4d3a2f..4e9daf4 100644 --- a/README.md +++ b/README.md @@ -1,12 +1,42 @@ # Advisory Circular -This is a twitter bot that alerts you when any aircraft is circling. +This is a twitter bot that alerts you when aircraft fly in circles. You can see it in action at [@SkyCirclesLA](https://twitter.com/SkyCirclesLA). ![Example tweet](Screen Shot 2019-12-13.png?raw=true "Example tweet") +## Criteria for tweeting + +The bot will consider an aircraft to be "circling" if: + +1. In the past 25 minutes, the sum of the aircraft's bearing changes + is more than 1440 degrees. Port turns cancel out starboard turns + and vice versa--there needs to be a net change of at least 1440 + degrees. + +2. The centroid of the last 3 minutes worth of positions must be more + than 2.5 miles away from all known airports. + +3. The centroid must be located within the county of Los Angeles. + (This is just because I don't yet have airport data outside Los + Angeles County.) + +4. The aircraft must, at the moment of decision, be at an altitude of + 300 feet or more. + +5. If an aircraft was previously circling, it must be considered + not-circling for at least 20 minutes before it is again eligible to + be considered circling. + +There are a lot of weird flight paths that can meet criterion #1, and +I kind of like it that way. For example, see +https://twitter.com/lemonodor/status/1203033917483175936 (consider +whether we also want to detect something like +https://twitter.com/lemonodor/status/1204550831103590400). + + ## Prerequisites to running the bot **Set up a Pelias instance containing information for the geographical