Measured height facet vs L5 antenna

GPS/GNSS
1

Maybe it is because of VDOP values being higher. But I have measured a point with both the L5 antenna and the facet and my facet seems to be consistently low when checking into said points. I use the h1 and h2 measurements on each respective antenna using a spark fun rod (with tip cover removed).

Has anyone else noticed poor verticals with their facets?

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I got .13 higher with facet on point elevation and just swapping heads.

When I’ve checked good NGS benchmarks I got 0.03 vs established elevation with L5 antenna and postcard. My facet meaaured .15 higher

2

I noticed that the label on the facet corresponds to the RTK 61.4 and 57.4 above but the website shows something off a magnitude of difference?

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3

That’s the differences in Physical/Mechanical Phase Center and the actual RF Measured Phase Centers.

4

So are those the heights we should use to get accurate heights? I assume we want the RF measured phase center and lowering the height slightly might get me to perfect elevations per the geoid

5

Just looking at L2 being a difference of 3 cm that would explain my .1 off a benchmark for local benchmarks

6

Yes, use the values from the NGS Calibration for both antennas :wink:

7

Big thanks my engineer friend! Oh by the way we even have the same name :slight_smile:

Time to go do some more experiments today. This stuff would be important for doing FEMA elevation certs since you can do that with static. Also the reason why I’ve been playing around with all this stuff prior to doing any work or my stamp next to it LOL

1 Like
8

We are practically kinfolk.