Everyone,

I've just pushed an attempt to fix the false alerts by introducing and applying a normalized GPS "signal quality" level from the satellite count and HDOP.

From analysis of my collected GPS data I've come to the conclusion the HDOP isn't a reliable standlone indicator. I've seen coordinates off by 8 kilometers with HDOP at 1.5, which should normally mean "nearly perfect". Only by taking also the satellite count into account, all false position readings could be filtered.

https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/commit/8aa6004efbf39d87e3077d01c8fefda59496def0
GPS: add normalized signal quality level, add web UI live status info
Location: flatbed movement alarm only with reliable positioning

  New metrics:
    v.p.gpssq                           -- GPS signal quality [%] (<30 unusable, >50 good, >80 excellent)
    v.p.gpstime                         -- Time (UTC) of GPS coordinates [Seconds]

  New configs:
    [vehicle] gps.sq.good               -- SQ level for location state "reliable", default 60
    [vehicle] gps.sq.bad                -- SQ level for location state "unreliable", default 40

  New events:
    gps.sq.good                         -- GPS position is now reliable
    gps.sq.bad                          -- GPS position is now unreliable

For the Teslas I've added a simple 0/100 setting, and a satellite count based calculation for the Jaguar. Btw, the Model S adaption seems to lack handling for losing the GPS lock, and the Jaguar iPace seems to lack setting the GPS lock at all.

The quality level replaces the GPS lock status role for the location module: no location changes or flatbed alerts will be emitted while quality is "bad".

The quality formula and thresholds work nicely for my region, please test & report if changes are necessary. I've added the quality level to the MP "L" message, so you can easily check your levels from a daily data export. It's also included in the live widget of the web UI's status page.

Regards,
Michael


Am 02.04.22 um 21:30 schrieb Craig Leres:
On 4/2/22 11:06, Michael Balzer wrote:
Your parking lot has pretty good GPS reception with never less than 7 satellites in view, my case is near the edge of GPS unusability with some periods of only 2 satellites in view.

My condo has a detached two car garage and the walls and tar & gravel roof are fairly RF transparent. My dev unit is in the spare bedroom and there is aluminum (or similar) in the walls and roof that does a good job of blocking both gnss and siriusxm satellite radio so the antenna (attached to window blinds) does not have a 360° view of the sky. Essentially it can only see out the window (which I believe has a UV coating that probably degrades the signal some amount.

        Craig 

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