I live in a wooded area in PA and my property has approximately 15 points that define its boundaries. I am looking for a consumer/prosumer kit or solution to help me identify where the pins are. I have found about half of them using onX hunt and my iPhone. The others either aren’t there or are hidden, and I need higher accuracy to find them. I am looking for recommendations. I have spent a decent amount of time researching all sorts of solutions but there’s no clear winner and I’m looking for input from those who have experience. Thank you for any (helpful) suggestions you may have.
Welcome @ABB !
As you have already experienced, GNSS in the woods will be frustrating most of the time if you are expecting accuracy.
Having a “Tri-Band” receiver (L1/L2/L5) can help in some situations, but L5 isn’t a magic bullet that penetrates tree canopy at-will.
If you are in the market to purchase a RTK device, I’d look at “Quad-Band” receivers - which adds L6/E6 bands in addition to L1/L2/L5. You might find HAS to be useful in the future…in general. The Galileo High Accuracy Service (HAS) will provide free PPP corrections over-the-air.
It’s impossible to beat the value of the SparkFun PostCard, + SW Maps to get started in RTK.
Add an antenna such as GNSS Multi-Band L1/L2/L5 Surveying Antenna - TNC (SPK6618H) - SparkFun Electronics
You can power the PostCard via the USB connector, or add the Portability Shield and Li-Po.
If DIY isn’t your style, then the Torch is a good choice.
The main “trick” we use w/ RTK around trees :
Get away from the canopy as best you can to establish a RTK Fix. Then you have 30-60 seconds to “run-in” and collect a RTK position, or stake-out one. Don’t expect that position to be extremely accurate…but sometimes it’s the best you can do in the woods with GNSS.
Another trick is to establish good positions in open areas close to your POI. Use a tape to swing arcs from these points to recover the property corner (trilateration).
Correction Source - NTRIP:
It appears that KeyNetGPS is free in Pennsylvania, but I don’t have an account in PA to confirm that. PA wasn’t on my personal list of Free State Networks, so this might be recent?
A $10-$15/month subscription to Point Perfect Flex RTCM would be the next choice.
KeyNetGPS or PointPerfect will send you NTRIP credentials that you would enter into SW Maps, for real-time corrections. Naturally, that assumes you have Cellular Service 
You also might get lucky and find a free BaseStation near you on RTK2GO, but look into the PA State Network first.
Everything I’ve described above is considered a Network Rover, since we receive NTRIP corrections from a Base that someone else owns and operates. The next step in complexity is to install your own local Base near your project site, and send it’s corrections (actually observations) to your Rover over an RF link. However, having a local Base isn’t a magic bullet for heavy tree canopy either.
I hope some of this helps. Ask any questions that pop up.
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That is all very helpful. I will explore these ideas. Thank you for your input!!!
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@rftop , after reviewing the information you provided I went on the store and I selected the following items for the system. I wanted to ask if there are any other recommendations while I am ordering? I have 3-D printing capabilities. I can use for printing housing. One question regarding that, is whether or not printing with a carbon fiber ASA filament (my norm) is Ok for the module housing. Are there 3-D files available for the set up?
Items
CAB14132
DEV27510
SPK6618H
GPS26916
Thank you again!
When you say that you need more accuracy, have you any estimation of the accuracy with your current setup? Also, do you have accurate estimation of coordinates of yours pins? When going to a pin, I imagine that you do searches around it. Up to which distance?
Before going to RTK, I would go with an outdoor GPS like Garmin Extrex 30/32x. In smartphone, due to lack of space, GNSS antenna is small and not very efficient. They are slightly larger in dedicated GPS receiver.
BTW, for RTK, do you have cellular coverage in the area?
Just using Smartphone so accuracy is only good enough to get me in the general area. For the property pins I have found, they were openly visible. I have a weird shaped property with about 15 defining points (14.75 acres) and found about 1/2 of them. I want more accuracy (within 6 inches if possible) so if there is no pin, I have a reasonably confident estimate of where my line is. This is more for knowing where I can go on off-road vehicles, not for something more critical like building construction. I’m a little techy and do not currently own a separate decent GPS device, so I’m OK investing some money into a better system.
I do have an estimate of the pin locations.
I do have cellular coverage.
@rftop , KeyNetGPS isn’t free. Subscription is $$$$$! They quoted $375/month.
RTK GNSS may work for you, but if you are looking for metal pins a metal detector can be quite helpful.
You can spend a thousand dollars on a professional one, but I’ve found buried monuments/pins with a $50 one.
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Wow… I’m glad I mentioned I couldn’t confirm if it was free or not
I will “un-update” my list… LoL.
Sorry, I missed that post. Shopping Cart looks good to me.
I don’t know of any reason why ASA-CF wouldn’t work, but there are many folks here with more experience with 3D printing. Also, there are several posts about a 3D model for PostCard projects. I’m not much help there…I try to stay in my lane 
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If you happen to be a civil engineer, you probably have a few surveyor buddy’s. I am a survey technician and have experience working with survey grade GPS/GNSS equipment. In heavy tree canopy, you will always have poor precision. The next best thing is to use a total station or theodolite. If you have software like AutoCAD you can draft up the recorded map of your property, or if it only has a legal description, map out the distance and bearing callouts. You can create coordinates and plug that into your Data Collector to then stake out the corners you haven’t found yet. But I know this equipment described is not easily accessible for an individual. So plan B, find two monuments to get oriented, take a compass and figure out your basis of bearings. Then calculate the next bearing and pace out the amount of steps to get close to the area of the next property corners. Have a metal detector and hopefully you will find a ring out. Have a shovel and dig about an inch down. Metal detect again, and dig a little more. Keep repeating this until you feel the monument, but try not to disturb it. Some really good surveyors can easily pace out 300ft and more and be within feet of their target. If you have any questions, let me know.
@tSteffen04, First, Thank you for the info! I’m a mechanical by training and I don’t have access to the equipment you mentioned, but I have compared the details in my legal property description, which was surveyed many years ago, to the information that exist in ArcGIS and it matches up perfectly. Given there are several existing pins I have found, I think I will be able to get close enough that I can use the magna-track (a recent purchase) to locate the remaining pins. Also, with the leaves having recently fallen, I am hoping the interference and precision will be better than if I were doing it mid Summer.
@ABB, assuming you have access to a CAD program that allows you to import points, you can perform a site localization manually.
You would import the GNSS locations of the pins you have recovered, those will never move in the CAD drawing. Then you take the constructed parcel that you draw from the legal description and place it on top of a particular pin location. Rotate the parcel to align with the other recovered pins in the drawing. Then export all pin locations from CAD to use in your data collector, smartphone, etc, to find the remaining pins.
Site Localization is translating and rotating a theoretical group of locations to “best-fit” with your actual gnss locations on the ground, to find the remaining ones. It’s so easy, even a Mechanical Engineer can do it [Sorry for the Civil Eng humor…or attempt]
Haha! Makes sense! I do have access to CAD. Thank you for the suggestion!
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