Topic: Calling All Surveyors - I have an inquiry

[dfarris75]

What is an inexpensive, yet good quality, gps data collector on the market and what is the approximate cost?

If there are none for surveying are there any consumer level gps devices (ie - Garmin) that can record points which can then be downloaded and imported into AutoCAD?

[Alan Cullen]

mmmmm...it's Friday night...I can't give you an answer until Monday.......sorry. 

But for what it's worth...I use Garmin (not the best IMHO)

[Bob Wahr]

Do you want GPS + data collector, or just a data collector?  I the latter, what GPS equipment do you have.  What kind of precision do you need?  What is inexpensive?

[dfarris75]

I was using the word "inexpensive" as a relative term as I am not a surveyor and have no experience with this sort of equipment. I only know of it and what it can do. So I want to know of an inexpensive (in regard to general pricing) gps data collector that one could collect field data (not topo necessarily, just horizontal info) and then come back to the office and download the point data to import into AutoCAD. I wouldn't say it has to be 100% accurate, but the closer the better within a few feet tolerance.

[mjfarrell]

I will need to do a bit of research, keep in mind cost is not the only factor.
There are many inexpensive GPS devices out there, however only a few can export the data in a manner that you can use in C3D, or even LDT.

[Bob Garner]

I'm searchin' my memory for this one.  I remember(?) a contractor laying out three transmitters of some type around a site.  Then using a hand held receiver which triangulated its location to a high accuracy relative to the transmitters.  The transmitters had to either be shot-in to local coordinate systems or located at "known" locations.

This was years ago.

On another note, there are those fantastic laser scanners that can graphically read a site/building/etc. and produce a 3d surface of everything it sees.  Someone else here knows about these things.  I can't remember that either.


Bob G.

[dfarris75]

The laser scanner would be wayyy over budget. I saw a demo of those once and the cost was like $60k as I recall. NO THANKS! I'll stick with a less expensive option if there is one.

Wish I had some experience with surveying and I'd have a better clue...

I recently saw someone say that you could import data from a Garmin, but rather than a format such as pnezd it was lat-longs or something.

I wouldn't be using it for 3d work, just 2d so the locations of the points would be what I'm after, preferrably on a known coord zone if possible. I'd just need a format that had point number, northing, easting, description, or even just northing and easting alone would probably suffice. I guess it was lat and longs then that would work too IF I could get it into cad. Not sure how easy that is...?

[Bob Wahr]

http://www.trimble.com/mgis_fcgps.shtml

[dfarris75]

I was looking at that yesterday, but didn't see pricing anywhere...?

[Bob Wahr]

They start about a grand and go up to about three grand depending on precision and options.  Trimble doesn't sell directly, you have to go through a dealer.

[dfarris75]

Ah they do have an online store. I found this one for $650. Not sure if I'd have to have more software to go with it or if I can take the raw data straight into AutoCAD from the device.

[Scott]

Lats and Longs can be converted to UTM pretty easy with CORPSCON.  I have used my cheap $200 Garmin GPS III Plus.  Downloaded the data import it into CORPSCON,convert it to UTM coordinates and import to autocad.  My $200 garmin probably isn't near the accuracy you are looking for, but the data can be retrieved and brought into autocad.  Some gps units can download data to a dxf file, which can be opened in autocad.  Not sure what unit it was, but garmin comes to mind.  I think it really comes down to the accuracy you want.  I have any rtk gps that will get you pretty darn close, but you are looking at several thousands of dollars for one of those.

[dfarris75]

How accurate would you say your Garmin is?

[Dent Cermak]

Some of the hand held GPS units are surprisingly accurate. We get lat/longs from the cell tower site guys that are pretty accurate. We setup BIG dollar GPS units, do a minimum 2 hour burn, ship the data to OPUS and get results back that are supposed to be VERY accurate. Most of our OPUS results are a couple of seconds different from the hand-helds at the most. Plus they do not do a 2 hour burn. They get pretty close results for a LOT less dollars.
Most of the GPS units will give lat/long, but has already been pointed out, you can download a FREE copy of Corpscon and convert to any state plane coordinate system that is required. A very easy piece of software. Even I can run it. 

[Bob Wahr]

Just for the love of all that's holy, pronounce it core-con, not corpse-con.  The problem that I've seen with any GPS is that just like the little girl, when it's bad it's horrid.  That happens with the high dollar survey stuff too, but when you get crappy satellites, it's extremely amplified in the handhelds.  Hard to say what's good enough without knowing details of what's desired.

[sinc]

Also note that you can import Lat/Long straight into Civil-3D, and it will also automatically convert the Lat/Long to your grid system.  All you need to do is define a Point File Format that uses Lat/Long instead of PNEZD.  No need for other software.

[dfarris75]

Wow! I didn't realize C3D had that as a point file format. Very cool. The only thing is that I was planning on just getting regular AutoCAD for this operation (more than likely). I may just change my mind about that as I'd rather have C3D anyway and since I could set up a lat-long format that's just one more reason to get it instead.

Of course it is preferred that it is as accurate as possible, but is not necessary to be that close. It won't be used for true surveying, but for photographic purposes. The final product will be more for reference as opposed to measuring and design. If possible I'd want the most accurate unit I could get at a reasonable cost < $1,000. < $500 would be even better, but that $650 unit might be a good one if I can take the raw data straight from the unit into cad without having to spend hundreds (or thousands) on additional software. But if I could get something even less expensive such as a Garmin for $200-300 that would provide decent enough accuracy then that would be great.

[mjfarrell]

Rusty....C3D has any point file format one can create, in the point file format editor. 

We were involved in a road safety audit with a local county, they used a hand help PALM device with some kind of GPS application loaded.  I think the accuracy was under a meter, and sufficient for the task they were put to.

[dfarris75]

Any idea what the device was and the cost? Accuracy within a meter sounds pretty expensive.

[mjfarrell]

http://www.palm.com/us/support/accessories/gps_navigator.html


Not sure if this is the same set up....

There is some good information for you here: http://www.consumersearch.com/www/electronics/gps/

[Dent Cermak]

I guess it all depends on how accurate you need your data. All shots taken should all be "relative" to each other and possibly only the "real world" coordinates would be off. In theory anyway. The hand-helds I have compared to were used for cell tower locations where your X,Y positional tollerance is 50' +_ and Z tollerance is 20'+_. Garmin has a unit called the Colorado400T that uses the WAAS technology that gives results within 3 feet. This unit lists for $599.99.
The cost rises rather steeply when you get into the "survey accuracy" instruments that are supposed to yield subcentimeter accuracy. Then you are talking megabucks.
Thing to do is decide on your accuracy requirements and then surf the manufacturer's web sites, They all have a :cotact us" link, co bug the crap out of them until you find what you want. Then ask them for a discount. They like that. Sometimes they will even do it.

[dfarris75]

Within 3 feet would be perfectly fine.

[cgrob]

A good place to ask a Land Surveying question is this messageboard:

http://www.i-boards.com/bnp/pob

Refresh the page often after you ask - answers will usually show up quickly.

[sinc]

Yeah, it's rather refreshing when someone on that board actually asks a survey-related question...