My mosaics are tracking 40 or more satellites most of the time, but they’re only using about 16 of them. The mode is set to rtk only. And as near as i can tell, i have all the Darrell’satellite bands turned on. I’m using a facet as the base. At this point, my f9ps are more accurate, but they’re using around 30 satellites. It’s very possible i haven’t got all the correct settings set. I’m still exploring and finding new things to set.
My mosaics are tracking 40 or more satellites most of the time, but they’re only using about 16 of them.
This is to be expected. You only need 4 sats to get a fix. The more, the merrier, but a GNSS engine will throw out the lower quality sats on a regular basis. The fact you’re seeing 40 means the mosaic is more sensitive, able to make better decisions about what satellites to use, but do not think that all 40 sats should be used in a fix to get a better one.
At this point, my f9ps are more accurate,
Do you mean in RTK Fix mode? The mosaic will be a few millimeters more accurate than the ZED due to tri-band and overall performance.
Do you mean in standard fix mode? I would argue that the mosaic in standard fix mode may not be reporting as low of an HPA as a ZED, but these values (HPA in standard mode) are very squishy and hard to compare between technologies and manufacturers.
Yes, rtk mode. My display i use measures in hundredths of a foot. Sitting still my zed moves up and down about 3 hundredths, the mosaic is about 7 or 8 hundredths.
In standard mode, if i know what you’re talking about, there’s no doubt that the mosaic is more accurate.
Yes, rtk mode. My display i use measures in hundredths of a foot. Sitting still my zed moves up and down about 3 hundredths, the mosaic is about 7 or 8 hundredths.
Hmm, the plot thickens.
0.03" = ~9mm
0.07" = ~21mm
That is a big difference, but still in the realm of believable.
Do you have L5 enabled on the mosaic?
Does your correction source support L5?
In general, I’d say use what works best for you, both the ZED and mosaic are very impressive. However, I would expect the mosaic to be performing closer to the 10mm mark.
That’s with the high precision turned on on the zed. Which seems to make a difference on how fast it updates.
I’m fairly sure i have the L5 enabled on the mosaic. My correction source is a facet and I didn’t think they were L5 capable…
Here’s how to enable L5 on the mosaic https://docs.sparkfun.com/SparkFun_GNSS … he-l5-band
979becker:
I’m fairly sure i have the L5 enabled on the mosaic. My correction source is a facet and I didn’t think they were L5 capable…
I’m not surprised you’re getting more stable RTK results with two ZEDs vs. a ZED and a Mosaic.
Your correction source (base) should be just as capable as your rover. The RTK solution uses the signals and satellites that both the rover and the base receive. If a signal or satellite is only received by one of the units, it’s not used in the RTK solution.
So if your base is a Facet (L1/L2 only), and your rover is a Mosaic (L1/L2/L5), the RTK solution will only use L1 and L2. And actually it’s a little more detailed than that, as there are multiple signals on the various frequencies, and different receivers use different signals on the various frequencies. More expensive receivers generally use more of the available signals given a generation/era of equipment.
The goal is to maximize the signals that both the rover and base have in common.
I usually use identical antennas, cables, and receivers in both my rover and my base. It’s an easy way to factor out a host of details that could cause minor problems. The RTK algorithm is using the small phase differences between the base and rover in each signal from each satellite; so it’s best to minimize anything that might cause phase differences the algorithm can’t account for. Cable differences should get sorted out in the clocks, but why tempt fate? There is a provision in RTCM for the base to transmit information about its antenna (eg name of the NGS calibration model) but I don’t see the Facets doing that. Identical receivers is a quick way to ensure commonality among the signals received.