Trimble or Topcon?

hi t dirt,

One of my mates has 3 topcon 3dmc systems on "pans" with all the latest software and hardware and is having some issues with his designs rotating on the screen and the heights changing to match that rotating position (can you see the problem that would cause on a batter?). As is fairly typical, the dealer tells him that he is the only one having this problem but he knows of 2 others who have the same drama. The curious thing is that the tractor has a Trimble RTK Autopilot system steering the tractor getting corrections from his Topcon base station. While the steering is still maintaining a straight (and repeatable) steering line the design on the Topcon screen is rotating occasionally.

I told him I'd ask here to see if I can find a solution for him. Any thoughts?

I have heard of similar problems with Topcon due to the single mast antenna needing to be in motion to figure out the orientation. I have heard of them being confused fora and aft as well.

I like the dual mast on the Trimble so it knows the orientation at all times. Not that it is flawless, but it just seems to me to be a better way to go. I could really se it being a problem on any kind of a slope, or "batter" if you will.
Never figured out the down under crowd calling a slope something we would make a cake with, but whatever your pleasure.

As far as a correction goes, I do not know, but maybe someone with Topcon experience will pick it up.

aglasergps said:

hi t dirt,

One of my mates has 3 topcon 3dmc systems on "pans" with all the latest software and hardware and is having some issues with his designs rotating on the screen and the heights changing to match that rotating position (can you see the problem that would cause on a batter?). As is fairly typical, the dealer tells him that he is the only one having this problem but he knows of 2 others who have the same drama. The curious thing is that the tractor has a Trimble RTK Autopilot system steering the tractor getting corrections from his Topcon base station. While the steering is still maintaining a straight (and repeatable) steering line the design on the Topcon screen is rotating occasionally.

I told him I'd ask here to see if I can find a solution for him. Any thoughts?

Click to expand...

if he has only got one antenna on it that might be the problem??
but if not call trimble and i garantee you they will put a demo system on it and after he has tryed it out he will never use anything else
when it comes to automated gps systems there is none better than trimble!!!!!!!!!!

Anybody wanna buy 3 (near new) Topcon 3DMC systems?

No thanks, I'll stick with Trimble.

aglasergps said:

hi t dirt,

One of my mates has 3 topcon 3dmc systems on "pans" with all the latest software and hardware and is having some issues with his designs rotating on the screen and the heights changing to match that rotating position (can you see the problem that would cause on a batter?). As is fairly typical, the dealer tells him that he is the only one having this problem but he knows of 2 others who have the same drama. The curious thing is that the tractor has a Trimble RTK Autopilot system steering the tractor getting corrections from his Topcon base station. While the steering is still maintaining a straight (and repeatable) steering line the design on the Topcon screen is rotating occasionally.

I told him I'd ask here to see if I can find a solution for him. Any thoughts?

Click to expand...

Hi all, I'm Dave a Land Surveyor from the UK. I have extensive GPS and Ground Modelling experience and am putting this to good use with GPS machine Guidance.

I have just set up a company in the UK dealing with the Prolec Digmaster Pro and PCX-3D systems.

I have seen the exact same thing on my own Digmaster Pro with twin antenna's.

It's more than likely that it's the number of satelite's overhead and their geometry. On my system there is a traffic light that shows green for dig and red for don't dig (when satelite geo is duff)

When it drops to red (less than 5 sats to get a fix) my profile screen remains good and true but look at the plan screen and and it shows you being out of position.

Also if the Base is pumping at less than 20hz to the Dozer it'll constantly be sluggish and jerky. Dozers need 20hz plus, Excavators only 5hz.

I'm sure the Topcon 3D MC2 was boasting 100hz data stream IIRC.

We use a custom JAVAD GPS system with Dual Channel (GPS + Glonass) antennas. You can have you own custom systems sorted easily enough via third parties. We essentially strip out from the GPS kit what isn't needed, providing our clients with lean, quick and accurate fixes.

Can I also put to bed the myth that there is something wrong with Glonass.

The key thing to remember is that the more satellites over head the longer you can work in areas with lots of obstructions. Its as simple as that.

Single channel is a no no nowadays in the survey world, dual channel allowed me to survey here!-

Please excuse my bad language at the end! And the shoddy video, it's from a camera phone. But it gives you the basic idea.

Ignore the link, It seems as though I'll have to find another way to post it.

Its showed the Topcon Hiper Pro working very well under quite ridiculous tree cover on a mainline gas pipe (48") we did the as-built survey for.

Here is another pic from the same Job. This was typical of where the Dual Channel Topcon wiped the floor vith Single Channel!


Top of the 'Hole'



9 metres down!

Flewy_86 said:

Hi all, I'm Dave a Land Surveyor from the UK. I have extensive GPS and Ground Modelling experience and am putting this to good use with GPS machine Guidance.

I have just set up a company in the UK dealing with the Prolec Digmaster Pro and PCX-3D systems.

I have seen the exact same thing on my own Digmaster Pro with twin antenna's.

It's more than likely that it's the number of satelite's overhead and their geometry. On my system there is a traffic light that shows green for dig and red for don't dig (when satelite geo is duff)

When it drops to red (less than 5 sats to get a fix) my profile screen remains good and true but look at the plan screen and and it shows you being out of position.

Also if the Base is pumping at less than 20hz to the Dozer it'll constantly be sluggish and jerky. Dozers need 20hz plus, Excavators only 5hz.

I'm sure the Topcon 3D MC2 was boasting 100hz data stream IIRC.

We use a custom JAVAD GPS system with Dual Channel (GPS + Glonass) antennas. You can have you own custom systems sorted easily enough via third parties. We essentially strip out from the GPS kit what isn't needed, providing our clients with lean, quick and accurate fixes.

Can I also put to bed the myth that there is something wrong with Glonass.

The key thing to remember is that the more satellites over head the longer you can work in areas with lots of obstructions. Its as simple as that.

Single channel is a no no nowadays in the survey world, dual channel allowed me to survey here!-

Please excuse my bad language at the end! And the shoddy video, it's from a camera phone. But it gives you the basic idea.

Click to expand...

I have to disagree with you on the Glonass. I use it when necessary, and only when necessary. If there are enough birds for gps then Glonass should be turned off.

As far as rotating screen issues I have only seen it with topcon systems. We run one system with Carlson grade and a single mast without any problems and all the trimble accugrade systems function fine. I would only run trimble with automated systems, but if indicate was all I needed I would use carlson.

AGGIE SURVEYOR said:

I have to disagree with you on the Glonass. I use it when necessary, and only when necessary. If there are enough birds for gps then Glonass should be turned off.

Click to expand...

Thats intersting A S, has it caused issues for you using the Glonass signal? I see elsewhere in this thread others saying they've achieved a better grade using just the GPS alone.

I must admit certainly here in the UK I get a quicker fix on my Topcon Hiper Pro kit I use for surveying than with any other GPS kit I've used.

Funnily enough I was doing the Topo survey of a site yesterday which I'm using for a demonstration show next week.
Looking at the sky plot when surveying a hedgeline with a large copse of trees overhanging the hedge on my side, I had only 4 GPS birds in view plus 3Glonass. The extra few Glonass enabled me to carry on working but when I turned off the Glonass birds, It would stay on float due to there being less than 5 birds in total to get a fix.

I suppose it depends heavily on the lie of the land you're working on.

If you're working where you have an almost unlimited view of the sky, clearly you'll see and be able to use a greater number of the available GPS birds
which is great!

I sell my clients a NavCom GPS system if they are working in nice clear sites as it reduces the cost a bit compared to Dual channel. At the end of the day, if your system is producing the results you want then thats all that matters really.

It'd be good to drum up some more discussion on this as I'm sure we could all learn a lot from each others experiences

With you on the Carlsson Software, excellent kit!

Cheers, Flewy

That's what I was syaing. I get better results and tighter grade without glonass, but when the sky is closed due to buildings or trees I turn it on. If accurate grading can not be achieved because of a lack of birds then it is time to puul out the robot and rum machine control that way.
I too build models, calibrate sites and support my customers with their equipment. I find that trimble is the easiest to teach someone on and is the least overwhelming. I took a blade hand with 30 years experience who had no desire to use anything other than bluetops and had him humming in one hour. After one day he was hooked and doesn't see the point of working without it.
I look back at the six years I spent as a superintendent moving dirt and can only imagine how much more productive we could have been and dollars added to the bottom line. In my experience there are very few jobs too small for machine control.

I don't understand any of this at all. My experience is that the Trimble GNSS solution is definitely more accurate and repeatable than the GPS only one - especially since we installed the latest V4.0 software into our Trimble GNSS receivers and bases earlier this year.

I think there are enough good Glonass satellites overhead that this new software is able to choose the best ones (GPS or Glonass) to use - keep in mind that it's not the number of satellites that creates a good positional fix, it is their location in the sky and the integrity of their individual signals. The receiver just has to be smart enough to work out which it should be using.

aglasergps said:

I don't understand any of this at all. My experience is that the Trimble GNSS solution is definitely more accurate and repeatable than the GPS only one - especially since we installed the latest V4.0 software into our Trimble GNSS receivers and bases earlier this year.

I think there are enough good Glonass satellites overhead that this new software is able to choose the best ones (GPS or Glonass) to use - keep in mind that it's not the number of satellites that creates a good positional fix, it is their location in the sky and the integrity of their individual signals. The receiver just has to be smart enough to work out which it should be using.

Click to expand...

this is my experince too
5 years ago when i got my first dozer with trimble/accugrade gps i started out only with gps and it was a pain in the but two times every day i could not do anything for about one hour because of to few sattelites and we had some problems with accuracy just before this happened and just after
but after half a year i got the new antennas with glonass and after that i has not had any downtime at all period..........and the accuracy increased a lot to
so glonass is a must today in my opinion

I had some down time today with my Topcon Hiper Pro's.

I had six satellites in view but in a line from east to west! Only took a few mins before things moved on and I could get back to work though.

I usually get about half an hour once a week where things go like that but no more.

Actually, can you see the Satellite plot on the screen with the Trimble System? Its quite handy to see where everything is overhead relative to your position.

It seems there are mixed results with glonass, but for me recently grade has been tighter without. No doubt downtime is less with glonass and that is a good justification for using it, but when there are 8 or more birds above 10 degrees with gps alone I find it to be a better solution. The equipment I use is trimble r8 gnss and the contractors use sps851 and 880. Everyone will have their own experience and location and time of day do matter.

I found this video interesting in explaining how Topcon's new 3DMC squared system works. Check it out.

I am very surprised technical details on official Topcon web site
especially for 3D-MC2 sensor. They tell MC2 sensor combines a gyro, compass and inertial sensor to measure the X, Y & Z position as well as the roll, pitch, yaw and acceleration of the dozer. Gyro is inertial sensor itself. What else unknown inertial sensor they need? Picture of sensor show 6 blue arrows and 3 red circles. Why they need 9 axis while 6 is enough to describe any movement of dozer? Why they use left-hand thumb rule instead usual right to show circles direction?

Who knows?

Euler said:

I am very surprised technical details on official Topcon web site
especially for 3D-MC2 sensor. They tell MC2 sensor combines a gyro, compass and inertial sensor to measure the X, Y & Z position as well as the roll, pitch, yaw and acceleration of the dozer. Gyro is inertial sensor itself. What else unknown inertial sensor they need? Picture of sensor show 6 blue arrows and 3 red circles. Why they need 9 axis while 6 is enough to describe any movement of dozer? Why they use left-hand thumb rule instead usual right to show circles direction?

Click to expand...

Hello.
Who knows? afaik there is only inertial sensor, the gyro, but I could be wrong.
As far as right hand rule, this was written by the sales department no doubt, perhaps also the answer to the first question?
Please remember that very few really understand this.
By this I mean that although we can all use it, but do we understand the display? after all, on some TopCon units it is "only" windows XP, we can all program in C.
The GPS units are simple, so simple that most operators can easily replace a SMD if need be.
Remember, some of us may understand this far better than the sales and support staff, it is just like being a good operator, it is all about "Want to".
By working together, and at the level that WE can understand, we as a group all benefit.
Remember, nobody understands what we do better than we do, that is why I listen so carefully to the elders in our community.
Remember, teamwork gets the job done.

the gps system is only as good as the model builder i like both systems but the trimble is the only system i've used on a machine and i really like it i never usd a topcon on a machine but the trimble show's both sides of the blade but then again i never used a topcon on a machine

a little update!!
as we speak i am getting my D6T installed with the new vrs modem solution so in the future i do not have to use the base station the precision should be the same as with the basestation and it saves us a lot of money because i will always get the correct heights without calling a surveyor or have to get coordinates of the base
now i will simply press go on the screen and then i am ready to go nomatter where i am at

so another good reason to choose trimble:usa but maybe this vrs solution is only in demark??

GPS vs GLONASS

Hello.

I have finally completed my research on this matter.
First off, GPS vs GLONASS has a lot to do with WHERE you are on the planet.
Maximum accuracy is limited in the GPS system, dictated by national security concerns.
Civil GPS signals may be degraded, or even unavailable altogether, in some places, this is after all, a Military system.
GLONASS is of course, the Russian system.
The Russians might not degrade as much in a given area as the US, if at all, but the system is not complete, so, by itself, at this time is not that good.
http://en.wikipedia.org/wiki/Global_Navigation_Satellite_System
Now for Topcon.
I have no idea whatsoever about Trimble, have never really used it.
True, without motion, the Topcon units will not display a given direction, it can only display a position, just like a portable unit, however I have never had issue with this myself.
I simply set ground reference from the base to the rover.
Between my exact GPS fix and my relative position from the base I know where I am at all times.
Radios.
Since I am a radio technician I understand radio very well.
First off, antenna gain is only a small part of it.
The single most effective thing that can be done to increase range is elevation, why do you think radio towers are so tall?
At 900 MHz, with and elevated feed 11.8 dB gain antenna at 5 feet above the cab of my backhoe and the base antenna at 11 feet my effective working range is at 5+ miles.
I use LMR 400 cable and follow RF practice very carefully.
I also use a 160 MHz radio for the backhaul channel, 2 watts, zero gain but also elevated, 2 to 3 mile range.
Remember, none of the radio equipment is stock, external antennas and phasing were only the start.
I operate the radio equipment under 47 CFR15/90 rules.
The antennas are mounted in such a way as to allow branches to strike them with no damage.