In my area there are lot hills and heavy tree cover. Will a local base station be more accurate that network RTK. There is state control base station 1.5 miles away and I still have trouble getting a RTK lock on some points.
My rule of thumb is +10mm inaccuracy for every 10 km away from the base. So 0-10km = ~10mm accuracy, 11-20km = 20mm accuracy, up to about 70km where RTK engine may not be able to get a fix at all. At 2.5km (1.5 miles) you’re really close to your base. I think your tree cover is contributing much more to your issue. And depending on how deep or narrow your valley is, that may be adding problems as well. My only recommendation is to use an RTK receiver that receives as many bands as possible (L1/L2/L5 ideally) and use as big of an antenna as you can handle (UFO style may be better than say small helical).
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Proximity, and commonality of view is the most helpful.
With your own base station you can also reduce the elevation mask to get more satellites potentially available. RTK gets primarily applied to those measurement with which the base and rover have commonality with, and once ambiguity resolution has been achieved that can be carried forward will carrier lock is maintained. This can be pushed out to 4 mins with configuration.
More satellites means bigger RTCM3 messages, so higher bandwidth on the communication link.
You can also control the constellations available, which might be limited by political stance of the provider, and their installed equipment. Check what messages the Network RTK is furnishing, and the number of satellites each contributes.
Having your own Base provides a lot more control in your experience, and reduces dependencies on third-parties.
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Heavy tree canopy will always be a problem for RTK.
Having a CORS so close is uncommon for most people.
In clear view of the sky I get a 14mm lock. I have some creeks that at the bottom of large hills covered in big trees, those are the problem areas. Would a fixed base very near (500 ft or less) to the rover fix this? My rover is a Facet.
Technically speaking, having your own Base is a benefit for sure… But it’s not going to work any miracles with the Tree Canopy.
If the rover can’t satisfy it’s requirements to transition from Float to Fix under the canopy, having a slightly closer Base won’t provide anything magical.
There are some field techniques we use in these situations. A simple one is setting/collecting straight-line offset points (away from the trees) and measuring over to your POI with a fabric tape. Naturally, the workflow gets much more complex if you need accuracy or elevations under the heavy canopy.