Hey All,
It seems like there's major differences in schools of thought when it comes to having a *bad* lock on GPS. Flip the pole, reboot the radio/bluetooth, etc. What do you guys find works the best?
For an example of a situation, I was working around some train tanker cars today, and after getting into an open area, the 3DCQ (Leica) was upwards of 0.070-0.100 m, with a full on lock, 10 sats with 8/10 on both L1 and L2 signals, and receiving RTK corrections (we usually sit in the ballpark of 0.010-0.025m).
My usual trick in the past has been to either increase or decrease the horizon cutoff from whatever has been set (usually 10* or 15*) to either 45* or 0*, and then back to the initial setting after about 30 seconds or so. My party chief today ended up taking the unit and did a powercycle on the BT-enabled puck (can you tell i'm Canadian? :-P), which then took upwards of 2 minutes to re-initialize...
I am not sure how to get a "better" lock...personally, I have increased the mask angle, and disabled noisy satellites, but that was just to get a fix...not necessarily a more accurate one. Some people will probably recommend disabling GLONASS...though I never tried it.
If there is even the slightest chance of a false "lock", we will flip the rod and re-initialize. I never received the same bad results twice.
For us, if the goal is super accurate results near obstructions, the only answer is the robot.
I've found that if the Sat's are close to each other things slow down or undesirable reporting. If you have plenty of Sat's turn off a few to spread the angle between them. In prove your triangle strength.:-)
I too have found this phenomenon to occur. The receiver says fixed, but you can tell soothing isnt quite right.
My data collector has a button that claims to reset the receiver, but in practice, it doesn't really seem to. I put my hat or hand on top of the receiver (antenna) until it goes autonomous. And that seems to work. Changing the mask forces the same thing: essentially a true disruption in the solution forcing the receiver to come up with a new resolution to the ambiguities.
Sometimes this seems to be a Glonass thing. Going GPS only often helps...
(Topcon GR-3 or HyperLite+ with Carlson SurvCE)
This is why it is good yo break lock, go away, come back and check your work. And if it really matters, check it again at least half an hour later...
3DCQ has a horizontal and vertical component. We all know how much the vertical component can be influenced by satellite geometry, but do you?
I don't understand this at all. Are you saying the manufacturer's software is not smart enough to make the best combination of available satellite signals?