Your mask needs to change relative to the SV position, i.e., if you have a lot stacked out at the horizon, you probably want to up it to 20å¡ or at least 15å¡ to cure some poor geometry.
As far as sampling rates, for RTK it's non-negotiable. 1 minute shots, re-done three times, evaluated, and averaged in the field with respect to the residuals reported. If they are more than 0.03', then we keep measuring until we figure out which is the bad culprit. Also, each observation is under a new initilization made in a different direction, approximately 50' away.
This yields excellent results. Yesterday we did this on some old legacy control points to roll the file to grid. After all points were shot, legacy points were reduced by the appropriate grid factor, we had results on the 0.01' magnitude between values.
gschrock, post: 337695, member: 556 wrote: Yes David, you have been running both base and rover at high rate
Gavin has it right.
John Evers, post: 337691, member: 467 wrote: WE ARE NOT TALKING ABOUT POSITION UPDATE RATES.
Neither am I, not exclusively.
John Evers, post: 337691, member: 467 wrote: We are talking about BASE TRANSMISSION rates. As far as I am aware, only Javad has implemented this. Just because you purchased the 5hz option for a receiver does not matter. That would only affect its use as a rover, not a base.
Shawn Billings, post: 337702, member: 6521 wrote: I'd be surprised if anyone is getting 5hz transmit over uhf.
This is your surprised face. My base is outputting at 5hz, I use spread spectrum at extremely short baseline lengths. (under 1000 meters)
John Evers, post: 337691, member: 467 wrote: Above, "dmyhill" commented that he runs his rover receiver at 5hz, as a one second update absolutely stinks for stakeout work, and I agree.
What I actually said:
dmyhill, post: 337659, member: 1137 wrote: (Both Base and Rover are 5hz....)
John Evers, post: 337691, member: 467 wrote: If you do not think that there is a loss of precision caused by using an extrapolation mode, it is only because you have not tested it to prove it. (it is small, but still worth eliminating).
Sounds good.
Look, I don't argue with the benefits, I agree. I do take exception to the idea that this is exclusive to one manufacture, when clearly it is not. Perhaps it is the case that Javad makes it financially accessible, more so than other manufactures. And, if they are running a propriety 5hz RTN, and willing to pay for the bandwidth, then more power to them!
Gavin, you'll have to help me out. I'm not sure what mess you'll be putting to rest. Will you be demonstrating the >1Hz transmit improves TTF? Will you be demonstrating how users of dmyhill's equipment can do the same?
Dmyhill says "This is your surprised face" because I stated that I would be surprised if anyone is transmitting 5Hz over UHF. He "argues" the point that he is getting 5Hz through spread spectrum. Not sure what the argument is, I just said the same thing. Then Gavin says 5Hz works over SS and IP. That's also what I just said. You two have me wondering if my mic is on. You are framing this like it's some kind of argument even though to my simple mind, we're saying the same damn thing.
Then we get the discussion about claims to exclusivity. I'm not sure who has made that claim. The fact is, most are running 1Hz because that's how it's always been done. Most RTN's are piping 1Hz. Gavin has said he has at times broadcast >1Hz for his RTN, indicating that it is outside the norm. Most user reference stations are broadcasting 1Hz. If that's not actually true, I'll be happy to admit that I am wrong. But I'm pretty sure that I'm right.
Dmyhill runs 5Hz transmit. I'm guessing he does this because it has benefits in the field. This was the preeminent claim: high rate transmit translates to improved TTF in the field, most notably in hostile environments. Dmyhill, can you agree to that?
Because of the confusion that can arise between "positioning rates" and "transmit rates", the semantics matter. Because there is not a terribly clear convention for the difference, it necessarily must be spelled out. Dmyhill articulated very clearly he is broadcasting 5Hz. I'm happy to hear it and would like to hear of his experience with the higher transmission rate over 1Hz.
I'm very sorry this has strayed so far from the original question. I think I've contributed all I can to the discussion. To be clear. If you have the capability of transmitting greater than 1Hz, it is worth investigating, but don't be confused in thinking that positioning rate and transmit rate are equivalent.
