Incorrect maximum speed?

dimonchik8 years ago

Hello dear Anton!
Just I noticed that the report wrongly given maximum speed. Maybe I have something not right do.
Report:
Time period: 2016-07-19 00:00:00 - 2016-07-20 00:00:00

Route start: 2016-07-19 17:40:56
Route end: 2016-07-19 20:19:54
Route length: 21.48 km
Move duration: 2h 38m 58s
Stop duration: 0s
Top speed: 49 km / h
Average speed: 15.58 km / h
Overspeed count: 0

Run SQL query:

SELECT MAX (speed) FROM positions WHERE device_id = 1 AND time >= '2016-07-19' AND time <= '2016-07-20'

Result: Maximum speed: 26.45789300000000 km / h
What's wrong?
The report gives a result almost 2 times more?
Thank you!

Anton Tananaev8 years ago

First of all, Traccar doesn't currently have a report that returns top speed. You must be using some unofficial version/extension.

As for speed value, it is stored in knots in the database, so your SQL query returns knots (not km/h). If you convert 26.46 knots to km/h, you will get 49 km/h (same as in report).

dimonchik8 years ago

Oh, thank you very much! :-)
Most likely I badly read the documentation!
Thank you so much you Anton for your great work and your help!