Couple questions come to mind as I'm still learning my new Trimble R10 along with the access software.
1) What is an observed control point and its function?
2)What is a control point? I've seen the box available for checking.
3)More epochs or more time for a "topo shot" that you would prefer to have greater accuracy? Let's assume multiple redundant shots won't be taken for averaging, just one shot and then a dump of the receiver head to stakeout out previous point to verify location. I believe i read something about being able to stop satellite tracking with a couple of clicks without dumping the head but I haven't searched for it yet.
1) 180 Epoch shot, slightly over 3 minutes. More dependable, use for control points or boundary ties.
2) Access categorizes points with different qualifiers, if you want to easily be able to copy control points between projects without having to individually select them, this is the way to go.
3) Default is a 3 epoch, 5 second shot with Access, which is fine for most open topo. If I get near any kind of canopy or obstructions, I usually crank it up to a minimum of 15 epoch, 15 seconds just to be a little more certain of my shots.
Is there a way to set different tolerances for different type topo shots without having to manually change the epoch and time for each different shot? Maybe set a topo A for boundary corners and a topo B for shots not quite as pertinent.
You can always stay on a point longer than the minimum required.
JaRo, post: 384545, member: 292 wrote: You can always stay on a point longer than the minimum required.
One of the options in the Options or Survey Styles is to "auto store". If that is unticked then the GPS will run on.
From memory, you are only allowed three different types of record - quick, topo and control. They can all be customised how you want though.
1) Per above, your three options are Rapid Point, Topo Point, and Observed Control. Rapid takes the instantaneous position; it's fast but 80% of the time it's interpolated between epochs, I like to let the position settle for a second or two if possible. Rapid is good for getting out of the middle of the road in a hurry.
The default for Observed Control is 180 seconds / 180 epochs. You can change the defaults for any of the three types, and as said above if you don't check Auto Store they'll continue until you manually stop them.
When you perform an Observed Control measurement, the position continues to converge over the 180 seconds, and each of the 180 epochs must agree with the position to whatever your tolerances are set at. This is why it can take longer than 180 seconds to get 180 epochs in poor conditions.
2) Per above. Also, that coordinate will be held fixed in Access and TBC, although you can edit it in TBC.
3) "Dumping" the receiver is ineffective; there is an option to reset the satellite tracking. I believe that it's under the Measure menu; the first thing that I always do is add it to my Favorites. You have the option to reset the RTK or reset the SV Tracking; make sure you reset the tracking, that forces a complete loss of lock. If the R10 ever hangs up at around 1' precision and won't fix do this as well.
When you shoot a point using the same point ID in Access, you have several options for how to deal with the duplicate. If you select Average, the software will display the deviation of the measurement from the previous coordinate that was stored. If you then store the averaged position it will display the coordinates and their standard deviations. I use the option Store Another if I don't need to use the averaged value in the field, because I do the averaging in TBC.
what, Lee, you don't give it a new name and then inverse to see how close it is? (sarcasm).
Never understood why people do that, all you have to do is set duplicate point tolerance to zero and it will tell you how close it is. I always use store another for both conventional and GNSS.
Lee D, post: 384587, member: 7971 wrote: 1) Per above, your three options are Rapid Point, Topo Point, and Observed Control. Rapid takes the instantaneous position; it's fast but 80% of the time it's interpolated between epochs, I like to let the position settle for a second or two if possible. Rapid is good for getting out of the middle of the road in a hurry.
The default for Observed Control is 180 seconds / 180 epochs. You can change the defaults for any of the three types, and as said above if you don't check Auto Store they'll continue until you manually stop them.
When you perform an Observed Control measurement, the position continues to converge over the 180 seconds, and each of the 180 epochs must agree with the position to whatever your tolerances are set at. This is why it can take longer than 180 seconds to get 180 epochs in poor conditions.
2) Per above. Also, that coordinate will be held fixed in Access and TBC, although you can edit it in TBC.
3) "Dumping" the receiver is ineffective; there is an option to reset the satellite tracking. I believe that it's under the Measure menu; the first thing that I always do is add it to my Favorites. You have the option to reset the RTK or reset the SV Tracking; make sure you reset the tracking, that forces a complete loss of lock. If the R10 ever hangs up at around 1' precision and won't fix do this as well.
When you shoot a point using the same point ID in Access, you have several options for how to deal with the duplicate. If you select Average, the software will display the deviation of the measurement from the previous coordinate that was stored. If you then store the averaged position it will display the coordinates and their standard deviations. I use the option Store Another if I don't need to use the averaged value in the field, because I do the averaging in TBC.
All good info. thanks again. I had no clue about using the same point ID and averaging automatically in the field. One question, if you don't select auto store you say they will continue until you manually stop it. Does this mean if I take a shot and the set number of epochs and timing is observed and I move my rover after this before hitting store I'm essentially getting coordinates where I didn't want them?
yes, but it will tell you "excess movement" if you have not yet stored it, assuming it didn't stop at the required number, you can move after it stopped recording and before you store if you have view before storage or something like that set.
I use auto store for rapid and topo, but not observed control.
Anybody routinely get bad shots using the observered control point method? I've had 2 shots in the last week thst weren't in the best locations but I've seen worse as far as canopy goes. During the 180 epoch session I received the error message that said something to the effect that positional tolerances couldn't be met (both horiz and vert were less than .10ft), and my option was to store or remeasure, so I chose to store since over 80 epochs had been taken.
I later stuck those points out and was half a foot off the shot coordinates
If you are just learning this you double any recommended time. Once you learn it then you will know when to shorten occupations.
Paul in PA
