Traccar: what is HDOP parameter using OsmAnd

Question

I'm making an app to insert GPS positions on a Traccar server. The "documentation" here https://www.traccar.org/osmand/ says that I must to send params using this API example

http://demo.traccar.org:5055/?id=123456&lat={0}&lon={1}&timestamp={2}&hdop={3}&altitude={4}&speed={5} 

But nothing about hdop parameter. What is that?

Answer 1

HDOP stands for horizontal dilution of precision. It's a term used to specify the Error propagation as a mathematical effect of satellite geometry on positional measurement precision. Essentially it indicates location accuracy.

But you don't actually have to provide it. HDOP parameter is optional as are most of the other parameters in the request.