How is reported speed calculated
Speed value is reported by the device. It's stored in knots in the database.
thanks, Anton. Ok so if I look at CSV output and SQL database output they are the same, and I can multiply that number by 1.15 ( knot = 1.15 mph ) and that gives me the web map site speed.
so I guess its an independent speed from the GPS coordinate calculated distance and the time interval. Any idea how reliable/accurate a speed is coming off an Iphone or and Android, or how that is done?
thanks.
Yes, speed is independent from GPS coordinates and time interval. It's reported by GPS module itself. Internally GPS module still uses distance and time to calculate speed, but at a much higher sample rate than server can do, so the value is more accurate.
So I guess the accelerometer and compass on the phone provide a more instantaneous measure of speed I guess by integrating over some time interval with some initial conditions. Its a more instantaneous velocity and wouldn't be expected to correspond to the average velocity between readings. that's a useful measure.
thanks!!.
It seems like you haven't read my comment. It has nothing to do with accelerometer or compass.
oops sorry, just trying to guess how the device calculates its speed with no communication to a satellite, like in a building for instance, where speed values are being reported, and somewhat accurately perhaps because I have an example in front of me of what looks like a speed profile of someone walking to an elevator, going up the elevator and walking from the elevator, and I know that is actually what occurred. I am using a phone app not a GPS unit at the moment. But will be using a GPS unit also. With a GPS unit I wonder how it would get a distance in a building. Magic! Thanks!
Sometimes inside buildings you can get a reflected GPS signal in which case you will have a speed value (probably inaccurate one). If your phone doesn't have a GPS signal, it will use network location, and the speed will be zero in that case.
Buenas tardes. ojala me pudieran ayudar. se los agradecería muchísimo
¿Traccar puede registrar acelerones y frenones ? me imagino que obviamente el equipo debe de tener esa función o tener integrado un acelerómetro.
¿donde se puede sacar un registro de estos eventos en Traccar? y por ultimo si alguien sabe si un GPS t103a o 303f de coban traen esa función.
saludos y gracias de antemano por los comentarios.
Good afternoon. I wish they could help me. I would appreciate it very much
Can Traccar register accelerations and brakes? I imagine that obviously the team must have that function or have an integrated accelerometer.
Where can you get a record of these events in Traccar? And finally if someone knows if a GPS t103a or 303f of Coban bring that function.
Greetings and thanks in advance for the comments.
How is your question related to the topic?
sorry me podría indicar como busco un tema relacionado o abro uno nuevo?
When looking at the web interface where the tracks are mapped and tabulated a speed is provided.
Where does this come from? How is it calculated?
When I download tracks to an SQL database or export a CSV file the speed shown is roughly 86% or the speed reported on the web site.
I have checked and the speed reported is not the reported distance of time interval.
Is it coming off the phone somehow?
thanks, for any assistance