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Old 28-01-2017, 12:52   #526
bcn
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Re: 12vdc Marine Computers

Petter,

this looks overly optimistic...

They claim 1cm PPK - post processed. Or 2cm RTK.
No spec of the receiver but as they are working with uBLox in the rest of the products the description looks like a uBlox M8. Now go and look what uBlox specifies. For the receiver.

This is a solution with differential corrections - one base station and a mobile unit - the "rover" - which has to be not too far away from the base station.
Emlid specifies 10km for a moving rover.

A L1 only solution requires very stable reception conditions. Very good sight to satellites and optimal sat distribution.

I think, you have one of their actual receivers and rovers. Over let's say 48 hours, how does the footprint look like? And if you move the rover, how stable is the track, how sensitive is it about disruptions? And dynamics in movement. GPS outages are not that important in marine environments (but in harbors or fjords) - but how fast does the rover recover after an outage and how does it drift (m/1min outage)?

Have you checked the reported accuracy against some benchmark? Accuracy, not what the internal Kalman filter is reporting as estimated error.

For the price of the systems a real-time 50cm (RMS) accuracy would be already sensational for a moving system.

Hubert
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Old 28-01-2017, 15:11   #527
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Re: 12vdc Marine Computers

Now I recall, Hubert it was you who posted some information about GPS accuracy I believe. Best device available, etc ??
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Old 28-01-2017, 15:34   #528
bcn
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Re: 12vdc Marine Computers

The answer will depend always from

- your application. Surveying is different from bathymetry or mobile mapping. Or just sailing. Or sailing and racing. Or evaluating autonomous vehicles.
A 2.000$€ drone from a photogrammetry campaign at 3000m cruising altitude

- accuracy required
- just position or position and attitude
- you need velocities in X/Y/Z and angular? Again accuracies..
- update frequency
- robustness

- the budget

So never the same trousers for everybody.

And what I heard say people in Spain: "Miracles at Lourdes"
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