LS+ Point Collection Under Heavy Canopy vs Using J-Mate

Jim Campi

Active Member
With the release of the LS+ and the significant improvements over the LS, do those of you that are using the new receiver with a T3 or 1M, find that this single receiveer and base congifuration is all you need to collect in difficult conditions? Heavy overhead canopy etc.

When the J-Mate was introduced I was thinking that this is precisely what I need. At times it can be madening waiting for the LS and T2 to to collect a difficult point.

I am not doing any boundary work (the surveying I do is in support of my primary engineering projects). I only carry the LS and T2. If I have a difficult point or points I usually can find a way to solve the problem (workaround) rather than going back to the office for a total station (thankfully).

Now that the + with T3 base has been around for modeerate term use and testing, I'm certain that most of you know it's rough limitations. For topo work do you need another instrument? Would something like the J-Mate, when the software has been refined and working as intended be helpful?

I was very suprised recently when I had my LS/T2 set up in the office (15 ft from 2 ave redidential windows on one side of the room only) that the LS fixed and was collecting a point on my desk. It finished and proceeded to continue. This has never occured before and says much about the work that has been done refining the software and improving the operation of the system. It is very clear that significant effort has been made in improving the existing systems. For me and my business operations, this has been very helpful. In fact, if something occurred that made your products unavailable or inoperable, then I would be forced to change my business practices in a negative way. It would take some time to recover.

As time progresses it seems that an alternate solution becomes less important. Am I mistaken here?

I must say that once the the the system is connected, it just seems to want to "run" in the field. This is a signifiant improvement to the conditions I first experienced with JField 2 (possibly 1) and working at 1 Hz (pre-beast mode). This is a testament to the hard work and dedication of the Javad team to contiue improving. All of you are doing a great job, particularly in light of the loss of Dr. Javad. Of course I did not know him personally...it seems pretty clear, based on what I do know of him, that he would be proud of the work that has been done keeping the business operational. I know the upper management must have had many long nights and perhaps some sleepless nights as well keeping the business on course. Again, great job to all of you. From my perspective the change has been seemless. Of course you are opening/expanding new lines of business, new website online etc. Of course the support from the 5 PLS has been outstanding. I know I must have personally tested the patience of the support team (Matt) and he continued without missing a beat, finding a solution to my problem. Ok, excuse my digression, I simply felt as though this must be said.

Thank you to the Javad team and any comments from those using the LS+ and T3 or 1M will be helpful.
 

ken larson

Active Member
The + and t3 base have performed extremely well and the money spent was recouped a long time ago. The checks and balances available provide the confidence you need to walk out of that swamp or off the mountain knowing you will not have to return for additional data. The support available on this board is 2nd to none.
 

Nate The Surveyor

Well-Known Member
The t2 - LS combo was the fastest around the track, for a long time.
The T3 - LS + was like adding a turbocharger to a Honda.
It literally sent me home early so many times in a row, that I'm astonished that more have not bought LS's. I'd say that if The t2 - LS combo could finish a job in 6 hrs, the T3 - LS + would finish the same in 3 hrs. I usually take ridiculous shots now. Really crazy ones. So, I'll still still take 4-5 hrs.
N
 

Jim Campi

Active Member
The t2 - LS combo was the fastest around the track, for a long time.
The T3 - LS + was like adding a turbocharger to a Honda.
It literally sent me home early so many times in a row, that I'm astonished that more have not bought LS's. I'd say that if The t2 - LS combo could finish a job in 6 hrs, the T3 - LS + would finish the same in 3 hrs. I usually take ridiculous shots now. Really crazy ones. So, I'll still still take 4-5 hrs.
N
So Nate, do you feel confidnent leaving the office witthout another insturment (like a total station) for backup in the case that the Javad equipment (whatever config you are using) will not be sufficient? I am not referring to backup to cover equip inop or failure.
 

Nate The Surveyor

Well-Known Member
Jim, I've not looked through a total station in 5 yrs.
The answer is yes.
I've pushed my units as hard as anybody. They are for real.
If you can live with an occasional tenth, or two of error, it's the bomb.
If I get a weak shot, I just do it 2x or 3x. My goal is less than 0.05' error on every boundary shot. I don't always meet that. But, I can. With multiple shots, most of the time.
If I were doing engineering, I'd use total station more often. (None now). For certain shots, like construction staking curb and gutter, etc.
N
 

nusouthsc

Active Member
Jim, I've not looked through a total station in 5 yrs.
The answer is yes.
I've pushed my units as hard as anybody. They are for real.
If you can live with an occasional tenth, or two of error, it's the bomb.
If I get a weak shot, I just do it 2x or 3x. My goal is less than 0.05' error on every boundary shot. I don't always meet that. But, I can. With multiple shots, most of the time.
If I were doing engineering, I'd use total station more often. (None now). For certain shots, like construction staking curb and gutter, etc.
N
Nate,
Not to divert from the thread but you had posted previously about the process of collecting raw data on a really tough point and then downloading the base file and post processing those points individually. I was wondering what's your "baseline" occupation time on a really tough point? We are starting to utilize this feature and was curious of others experiences in really tough environments. 10 min has seemed to work pretty well but a few have failed. Any input?
Thank you!
 

A.lacey

Member
The setup i have in mine is 1.3 variable or rtpk 3. In really bad spots i usually will get 2 shots in under 10 min. I also always take at least 2 shots.
 

ken larson

Active Member
LS+ T3, I have mine auto accept with 3 60 sec rtpk agreements, but it has to be a real tough shot for it to get to that point. As for the 1.3 Var, I do not use auto stop as I have seen some bad results when it resolves too fast. I prefer to wait for the Cnf and Cns to both hit at least 7 along with the 1.3 Var. The RTPK and RTK agreement also are a clue that I am on the right track. The total station is in the truck every day, but is used most often for the prismless rapid location of improvements or for areas that are under too much cover against bldgs. Been a while since I have had to use it on the back 40 for a location.
 

hntwhitetail

New Member
When working under extreme canopy, how far is your base away? Are you finding that one open spot, setting up and working in canopy w the +? Say doing a 2ac boundary, survey and can setup 100 to 200ft away from your points to collect are you getting quick results?
 

ken larson

Active Member
distance from the base is not really a factor - the biggest factor is making sure the base is in a position that does not put grade or sometimes a structure between the rover and base. An elevated position for the base is also best.
 

hntwhitetail

New Member
LS+ T3, I have mine auto accept with 3 60 sec rtpk agreements, but it has to be a real tough shot for it to get to that point. As for the 1.3 Var, I do not use auto stop as I have seen some bad results when it resolves too fast. I prefer to wait for the Cnf and Cns to both hit at least 7 along with the 1.3 Var. The RTPK and RTK agreement also are a clue that I am on the right track. The total station is in the truck every day, but is used most often for the prismless rapid location of improvements or for areas that are under too much cover against bldgs. Been a while since I have had to use it on the back 40 for a location.
I was wondering which do you select on different shots, the rtpk or rtk? if rtpk is .0111 do you use the rtk shot or use the rtpk shot? or are we using rtpk when we are in extreme areas and only able to get one epoch? Just didn't know how most are choosing between which 2 to use in the field. Maybe I have missed this in other threads??
 

ken larson

Active Member
I believe the rtpk is supposed to be the best bet on a points position due to the fact that it has been processed with the base data.
 

Shawn Billings - Javad

Active Member
JAVAD GNSS
I wondered the same thing as we were developing RTPK. After discussions with the engineers and personal experience I can say that neither one is always better than the other. There will be circumstances when one solution type will be better than the other. An RTK position with a high Variety (>1.3) will probably be more reliable than a single short RTPK solution. Multiple repeat RTPK solutions (4 or more*) using more than 60 second intervals will probably be better than an RTK solution with low Variety (<1.3) or no Variety.

Remember that you can tell how many times an RTPK solution has repeated by the number in ( ) next to Fixed RTPK on the collect screen. It might seem counter-intuitive, but the number will show how many additional solutions agree with the initial solution, so a value of 2 means there are three solutions in agreement and a value of 4 would mean there are five solutions in agreement.
 

avoidthelloyd

Active Member
Like others, I have used a robot only once in the past 4 years. It was on an engineering project in tough canopy. My other crew got my T3 and broke out the T2 again this year and it is noticeably worst in canopy.

The main thing I learned the hard way in my mountainous conditions, is WHATEVER SATELLITES THE T3 BASE CANNOT SEE, IT WILL NOT SEND CORRECTIONS FOR THOSE TO MY ROVER. I would set up my base in less than optimum conditions like with open North sky but trees all on the South. Then I would go work in a spot where I had mostly Southern sky view for my rover. As you would expect, I could see satellites that I couldn't use in my RTK because my base could not see them at the same time. I just used to think "I spent a lot of money on this 'super base' and it will work no matter where I set it up". Haha.

If you can work without UHF limitations, set that base up high and wide open sky as possible!
 
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