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cf.67
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New Garmin GPS handheld logs raw measurements in RINEX

That could be fun. Submeter Garmin alert!

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jim.cox
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It has been possible to log Rinex from a number of Garmin units for a while now.

I have done so quite successfully.

Google GAR2RNX if you are interested.

But up until now the Garmin units only track the L1 signal, so post processed accuracy is at best only around 100mm (that's  around 4" for the metricly challenged)

 

 

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cf.67
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4" is still pretty sensational! I did go on a long and twisting google journey researching the various prior options like GRINGO and GAR2RNX and someone made a box at some point you could plug certain Garmins into that would log the raw data..not sure how succesful it would be in the Windows 10 era when it was all probably done in the Windows 95 era!.. .but a ready made device and all modern software is tempting - just for fun and games and experimenting. If any one has an older 60,62,64 and was planning to upgrade this would be an interesting thing to play with.

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thebionicman
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L1 only isn't the most limiting factor. I did tight work with a number of L1 units. The lack of a decent antenna (and model) is the issue

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jim.cox
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Take a look at the Garmin GPS 19x unit.

It is a waterproof marine antenna and reciever in one unit, designed to be pole mounted. 12V power and serial output. Its data can be logged and converted to Rinex

Works well for me.

There are also some units that will take an external aerial - from memory the 12XL is one

 

 

 

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Bill93
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What averaging time for 100 mm, and what is the ultimate limit for very long occupations?

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jim.cox
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30 minutes seems to be necessary.

You might like to take a look at these articles

ASSESSMENT OF LOW-COST GARMIN OEM GPS RECEIVER FOR SURVEYING APPLICATIONS

and

CARRIER PHASE SURVEYING WITH GARMIN HANDHELD GPS RECEIVERS

 

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Bill93
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I would note their very good numbers are for PPK base-rover vectors over reasonably short baselines, and the other paper used hours of data over distances typical of CORS spacing.

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Paul in PA
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That looks like a left handed ProMark 2. The ProMark 2 had the same insides as the mapping grade Map 330. The ProMark 2 could log the observations over time and connect to a precise antenna. I would not be surprised if it were using the old Ashtech Data Logger program.

Paul in PA

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Paul in PA
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AH? But what part of the L1 signal is being used. As I recall the very early ProMark X was only using the L1 C/A code (coarse acquisition) not the P code (precise).

The first Trimble 4000S required an external computer for data logging, so nothing is really new.

Paul in PA

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