Survey Grade GPS for Mapping Grade Results

> I'm wondering if anyone has any recommendations/procedures they'd like to share for using survey grade GPS for mapping grade results. Here's my situation- I have been asked by a large hunting lodge to produce a map of key hunting spots, roads, etc on their rather large wooded property. I have two R6s which I typically use for RTK surveying. Given the accuracy requirements (none really but I'd like better than recreational grade GPS) and the rough terrain, canopy, skimpy radio signals, etc, I'm thinking RTK fixed positions will be rare and unnecessary. So is there any reason to even setup a base? Most of my shots will likely be taken from a moving ATV. Should I just setup my rover to record autonomous shots? I don't have TBC currently but should I setup my base and use a survey style that would let me post process my float data if I end up purchasing a license? (If TBC processes float data). Any recommendations on survey styles?
>
> Thanks,
> Jack

If I was doing it I would set my survey style to Real time differential and just use WAAS. Would be better than autonomous and you would likely be within 10' all the time and most of the time better than that.

you could install TerraSync on a Windows 6.5 mobile device and collect you data via Bluetooth connection. you can convert to shp in Pathfinder Office or convert to shp in TerraSync. depending on what version the R6 is as well the version of TerraSync. contact a reseller for a trial version of TerraSync and see if it will work. i use a HTC HD2 with Windows Mobile 6.5 to connect to my Bluetooth devices, it's fast and never crashes.

Why not just run it as RTK?

Or PPK?

I map a beach every now and then. I setup the base and put the rover on a backpack. Mapping grade because I do not have a perfect measure up and the backpack swings all over (a range of close to 3'). Of course, given the rapid changes in the beach, you cannot prove that my location was not perfect!

Thanks Drilldo, I had not considered WAAS. I just did a test run close to the house using strictly autonomous and got surprisingly good results. WAAS should make it even better. Thanks for the recommendation.

Jack

I think its going to be almost impossible to get the radio correction or that's what I'd do. Even with a 35 watt repeater and a 15' antenna pole the signal seems to get lost quick in the woods around here. Thanks, Jack

post process

Thanks Joan, I'm kind of opposed to installing "temporary" software as I try to get the longest life possible out of my computers. I used to use Pathfinder Office and Terrasync and liked them. If I had more demand for this type of work I might invest in the software and a GEOXH but the R6s still have me in a hole! :'(

I don't have TBC, yet! But, I'm also not sure if it will process float data anyway.

We have a few fellows around here that do this routinely..

sorry.. couldn't resist...

Depending on the size of the job, I would consider renting suitable equipment designed for collecting mapping grade GIS data. You would be able to quickly and easily collect the location, attributes (from a pre-programmed data dictionary), and a geo-referenced photo with just a few clicks, taps, what have you.

After post processing, it is usually not that difficult to get sub-meter or near sub-meter positions from the mapping units, which is perfect for mapping trails.

The data from the Trimble mapping grade data collectors can be downloaded and reduced in Pathfinder Office. The dealer would probably do that for you.

Less to pack around + less data entry/processing = more time to explore and enjoy your ride.

The ublot chip in the Mesa or archer 2 would provide pretty good mapping grade data.. if you had one of those. I reliably had about 2m most times I used it.

Not sure I would get the big gear out if you need mapping grade for a trail map. You could even use GIS software ArcPad for free (20 minute sessions)..

Just a thought.

I read the Hemisphere S320 can achieve 1 foot accuracy in WAAS mode.

Cheers

Not 100% but I am quite certain that Pathfinder Office will process Float data.

I second the WAAS correction. It will get you what you need and you will not have to bother with radios. The issue with autonomous, you really have no check if it begins to lose precision due to tree cover.

PPK would be another option, but given you don't have post-processing software, it doesn't seem worth the time or money.

~Raybies

WAAS and use the State Plane 1983 (ITRF to NAD83) coordinate system in Access.

I did a mess of wetland flags once a long time ago with just my L1/L2 hipers. I actually did static on each point, in order. Took a stopwatch with me, and did 30 seconds in medium heavy, and 60 sec in heavy canopy for about 100 flags. It should not have worked at all I thought, but I also hi a couple of conventional CPs on brushed lines that also had heavy canopy. My results after post-processing to a base station that was about 1500 feet away (in a field) were fantastic - certainly good enough for wetland flags on the job I was doing.

Don't over-think it, try just the old-turn-on turn-off and log static data on each and post process. Should get you close enough.

Why cant you just use RTK? Jack up the acceptable tolerance level and uncheck the "store only fixed solution" checkbox. I did this once with TDS and it worked pretty good. I have Carlson now, but I sure there is some way of doing it. Isn't that what code receivers do anyway?

BTW, when you are done make sure you restore your original setting for when you really need to do RTK work.

Thanks Lee. I didn't see today's responses until now but I followed your advice by luck. It worked great. Got everything shot out. I used continuous points on the trails and short topo observations on other features. Even had a driver for the utv provided, which is why it went so fast.

Thank you everyone for your responses. They are all greatly appreciated!

Jack

Thanks Bow Tie, radio was a going to be tough to get.

Thanks,
Jack