Need GPS Equipment Help!

928G Boy said:

GPS simply isn't as accurate as a laser. That's why laser augmentation for GPS exists. I don't know much about trenching but I've laid a lot of pipe... for anything pressurized GPS works good, but for drainage pipes GPS is a no-no.

When I was surveyor for an engineering company we'd check grade for waterline and dirt work with GPS, but for setting blue tops for a concrete pavement or staking/checking drainage pipe... The old rod and level is still the best.

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This really all depends on your acceptable tollerances for "accuracy".

In my mobile field drainage and grading applications the Trimble Ag RTK GNSS I use is more stable and way more repeatable than any laser transmitter, especially when distance becomes involved and I've been using lasers since 1979. In short distance applications (less than 200 meters) I'll agree with the laser statement but anything over that, lasers are too prone to all sorts of environmental influences (dust, wind, heat shimmer, fog, humidity, temperature inversions etc.). With my GNSS I have graded sand profiles over 5 km of track at down to +/- 5 mm (1/4 inch) with next to no additional control assistance apart from the original Bench Mark set up - try that sort of machine control with laser or total station.

It would also be successfully argued that static vertical accuracy with a satellite based solution can be a little bit variable and most guys using GPS for elevations would know that. Mind you, get a laser at a fair distance and you'd see more variation with that than you'd see from the GPS most times.







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GPS is more accurate than a laser when you consider real world scenarios. Too much room for error with laser. Have laid millions of feet of tile with GPS and no problems. Will never go back to a laser for accuracy and efficiency reasons.

Does anyone have any information about using 410- 470 hz compared too 915hz system.

I was told due too changes in FCC rules that using the 400hz system will be more restrictive.Can't be used mobile like it has been .So some gps equipment will have too be updated or scrapped?

Anyone care too give input about the difference in the 400hz and 900hz systems and how they work for you in your case.:usa

The UHF band (390-470MHz) is used throughout the world for surveying and machine control as it combines a reasonable bandwidth with good radio range. The popularity of this band results in frequent interference which may affect grading operations.

A license to operate is required in many countries, including the US. The FCC license is tied to a geographic area, making it difficult to operate over a large area while staying legal.

A few years ago, the mandated channel separation went from 25kHz down to 12.5kHz. New licenses have since been issued for 12.5kHz operation only. There has been talk of restricting it further, but I do not have the details at this moment.

UHF radios have a fixed carrier wave (you select the frequency according to which frequencies you have been licensed for). This means you cannot prevent interference from other sources. Coding the signal from the base station does not reduce interference, it merely ensures you don't accidentally pick up the signal from another base that happens to be transmitting on the same frequency. Also, having the right to a frequency in a certain area does not prevent someone from interfering with your operation. -It only gives you a legal right to have him shut down, -if you can find him. Work stoppage is not cheap, so be sure you properly evaluate the risk of interference before selecting which type of radio to go with.

900MHz spread-spectrum radios continuously hop between transmitting frequencies which greatly reduces the possibility of interference. They are license free in the US.

These radios have much greater bandwidth than UHF radios which enable them to be used for data transfer in addition to broadcasting positioning information.

The only drawback with 900MHz radios is that they have less range that UHF radios. They do not penetrate objects well, making it necessary to set up repeaters to cover greater areas. How many repeaters are needed depends on the job site. Long road jobs usually need more repeaters that building/plant job sites.

So, to sum it up:

UHF has long range (fewer radios = lower cost), low bandwidth and suffers from interference.
900MHz has short range (more repeaters - higher cost), high bandwidth and excellent immunity from interference.

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Everything you always wanted to know about 3D machine control

It is relatively easy to change the radio type in a 3D machine control system.

Whether you choose UHF or 900MHz, you can always change it later. -But, at a cost, of course.

Kellogg i have more questions imagine that !!!!! I have the Topcon GX60 box and now have a MCR3 machine reciver.Still need anntenna cables,plus need to decided on base station.

The Topcon wedsite says the MCR3 has the UHF radio and drivers and etc built in.I know i need the IMU sensor for the blade.

If i get a G3 base will i need a rover to make the machine work right now.The rover would be used too do survey with base right? but do i need rover on the trencher or will the MCR3 work if i get the information to the control box i need.

Hundred of question so bear with me.Would be using the AGPS software above in my other posts.

My MCR3 reciever says it is configured with Topcon digital UHF radio,but doesn't show the HZ it is running(your guess?).I thought i would have the S/N checked and maybe they could tell me how it was configured from the factory.I saw another MCR3 on the internet that was configured with digital UHF 410-470 modem ,so my guess they was using a network is that right?

Would like to get some other peoples idea what works for them.I'm commented too Topcon now like it or not.Thanks for all your input.Wish there was more discussion on this!

There are several choices for a base unit, HiPer Ga, GR-3, Legacy, GB-500, all UHF. You need a rover to localize the job. If you are just using the unit for elevation you may not need a rover.
digital UHF 410-470 modem It could have UHF and a Modem..
I have some used cables off a dozer if you are interested.

t_dirt is right. The MC-R3 receiver has a UHF radio built in and also celular modem capabilities should you want to run off a GPS network. (Meaning you wouldn't need a base). The MC-R3 complies with the current FCC regulations, so you don't need to worry. You still need to get licensed, though.

t_dirt also sums up the base station options. Just be sure it has GLONASS capabilities. (The Russian satellite system)

The 'rover' is the term for the roving GPS receiver, -the one used to survey the site and to do grade checking, stake outs, etc.

You can technically get by without a rover, but someone needs to localize the job (correlate lat/long/elev to the job site's Northing, Easting and Elevation). You could hire someone to do this at the start of the job, but I really would recommend you have a rover if you are to use 3D machine control. You will need one sooner or later, -probably sooner.

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Fundamentals of 3D Grade Control

Interference

If i'm using 410-470 UHF,and i'm located in midwest where there is lots of farm machines that are now using autosteer and more going to RTK with the tile plows,how congested and how much interference will we run into down the road?

Well it it get too congested and is other contractors seeing issues where they are located like bigger city populated areas?

If so are they moving more away for UHF radio and too the 915 mhz?

My work area will be more rural and can loacte base close too trencher so wouldn't be over a mile from my work.

T-dirt need a contact number or email ,i left you a pm on site here.Thanks

It is impossible to predict if and how much interference you can expect to encounter in your area. Listening for radio activity using a hand held scanner will give you an idea of how crowded the band is right at this very moment, but can't predict what tomorrow will be like.

If you are in a rural area, you will statistically be less likely to suffer interference, just because there are less people around as compared to an urban environment. All it takes is one transmitter, though...

It is my experience that people in the US is generally migrating from UHF to 900MHZ. There is still a large number of people using UHF, though, and they will likely continue to do so if they don't experience any problems.

900MHz is not allowed in Europe, so users there are still deploying UHF solutions. It is my experience that the UHF band is much less crowded there due to historically strict restrictions of any form of radio broad cast, so it is less of a problem. They can't use 35W boosters like so many in the US are using. (A big contributor to the interference problems, by the way).

Australia and New Zealand allow 900MHz (NZ has a slightly narrower band) but users there are reluctant to move from UHF because the better range they enjoy with this solution. Since these countries are not so crowded in the UHF spectrum as the US is, they have little incentive to switch. Requirements to transmit ever more data would be more likely to nudge them towards 900Mhz. However, in an area with good cell phone coverage, transmission via the internet and cellular modems would likely be preferred.

I don't want to sound as if UHF is not a functioning solution in the US. -It is. If you are in a rural area, I would expect you have a decent change of being able to operate daily without significant problems. Remember, you can always change the channel. The trick is to know your equipment so you recognize when you are being 'walked on' and take appropriate action.

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Learn about RTK networks for 3D machine control

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Welcome to the forum GeoRadarImaging.

Since this is your first post, I'm considering you haven't bothered reading the forum rules. This in an excerpt from the rules concerning advertizing on forum:

Aside from the "for sale" area, for member's personally owned goods, advertising of goods and services is not permitted unless sponsoring heavyequipmentforums.com. A vendor of goods or services may make one introductory post explaining their product or service and may answer questions about such within that thread. No further promotion of your product or service may be made without sponsorship.

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Since the rules allow for all members to make one introductory post about their goods/services, we will consider this to be your introductory post.

Hello,

I have Trimble GCS900 3D for sale.

If you interested to buy you can email me giant.warehouse@contractor.net

If you are set on Topcon then goodluck. If not and you would consider Trimble. I can help you with the Base Rover setup to working in about 4hrs with an office software class. YES it's that easy.

Hope you are happy with the topcon by now, the year you spent trying to get it figured out trimble would have had you up and running. Looked at both units before we purchased couldn't pass up the support offered from Ziegler, Altorfer and Trimble. We would be in the same boat as you if we chose Topcon, we don't have one person on the payroll just for our gps so we count on the support we get from trimble.

Duramax said:

Hope you are happy with the topcon by now, the year you spent trying to get it figured out trimble would have had you up and running. Looked at both units before we purchased couldn't pass up the support offered from Ziegler, Altorfer and Trimble. We would be in the same boat as you if we chose Topcon, we don't have one person on the payroll just for our gps so we count on the support we get from trimble.

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Where are you located?Did you try Star Equipment about the Topcon eguipment.Do you do tiling and dozing ?Thanks

Thought i would dig this one up again!!!!! Anyone using the new Topcon HiperII base and rovers.They are the Sokica??? recievers they was bought by Topcon.Any ifo weclomed.Thanks

I just bought topcon hiper II base & rover with tesla field controller . with pocket 3d/office 3d software . we like it alot .next step topcon 3dmc2 dozer control !

Thanks for the reply,was gone over the weekend or else i would have replied.I'm looking at the same setup.Got a few other questions.If you want you can pm me here on the website.

Base and rover did you go 900 or 450? Have you used yet.Having a demo tomorrow if weather straightens up.

My dealer is getting the qoute for the rest of my stuff i need for the machine contol system.I have everything except the valve and harness.He was down earlier last week and tested what i have and everything is unlocked.Lucked out there!