I had a much more successful day surveying in the woods with RTK Torch, Point Perfect corrections, SW MAPS, on an iPhone 11. The SW MAPS was reporting the RTK Torch bouncing between DPGS and RTK Float, and rarely RTK Fix. When it would get RTK FIX, sometimes it was only able to average a point for 7-12 readings before falling back to FLOAT or DGPS.
I was in the woods, so there are absolutely obstructions, hills (east Tennessee) but it seems to vary a lot on my success rate. And oddly sometimes it would get RTK FIX after sitting for 20-30 minutes just by moving it 10ft, and putting it right back where it was.
Since I cannot cut down every tree, but can remove a few branches, and I am using a 3 Meter (three) to get the RTK Torch up as high as possible the question is…
What are your tricks in remote areas (No NTRIP available currently) to get RTK Fix more often than not?
Are my expectations too high?
BTW - Seems to get RTK Fix if I am up on top of my ridges…
Ok, I will get the UBlox software and try setting the mask to 15 degrees and try again and see what happens. Does type of weather make much of a difference? e.g. clear, very low humidity day, vs. very overcast, about to drizzle, high humidity day?
I think I am now within a foot of where the pin should be, time to get the metal detector back out and the shovel to see if I can find the actual pin that the deed says should be there… And I can try from the other Pin direction but that pin is 1,512.98ft away and also currently unfound… but haven’t spent much time looking yet
You can quickly set that in the Torch itself. I’ve always used 15° and 30 dB-Hz.
[Note: The Torch has a UM980 chip, not a U-Blox]
Some will argue with 30 for noise, but it works great for me.
SparkFun RTK Torch v2.1
** Bluetooth SPP and BLE broadcasting as: Torch Rover-7C7A **
Menu: Main
1) Configure GNSS Receiver
Menu: GNSS Receiver
1) Set measurement rate in Hz: 1.00000
2) Set measurement rate in seconds between measurements: 1.00000
Note: The measurement rate is overridden to 1Hz when in Base mode.
3) Set dynamic model: Survey
4) Set Constellations
5) Minimum elevation for a GNSS satellite to be used in fix (degrees): 15
6) Minimum satellite signal level for navigation (dBHz): 30
7) Toggle NTRIP Client: Disabled
15) Multipath Mitigation: Enabled
x) Exit
Ok thanks - I am comfortable with the Torch Serial interface so I will do it that way… Thunder and lightning today, so maybe tomorrow I can field test.
well, I own a Kubota SVL75-3 and various attachments, I cannot afford both!!
Clearing part of the firebreak where I know for sure I am on my property!!
I tested this in front of the house on my 155ft test points, and it got RTK Fix way faster in my opinion. The area is much more open, but that 15 degrees may be a key to working in very hilly and obstructed areas. On the farm not uncommon to have a hill 50 high at a 35 degree angle or more - hopefully can field test tomorrow
Signals low in the sky pass through more atmosphere. Correcting for Atmospheric Conditions is a major part of RTK, and something we have a little bit of control over.
Lower C/N0 values can be a sign of multipath.
Since we are normally seeing 30+ Satellites, I don’t want the RTK engine to even think about using the “bad ones”… just go ahead and eliminate the possibility of those birds causing problems with the RTK Fix.
@ChrisO , Don’t be afraid to crank-up the Elevation Mask even higher.
More than 20° wouldn’t scare me a bit for normal work.
Being in the Hills of TN might call for a much higher Mask.
Low birds are rarely helpful, if you have plenty of choices at that particular time… which we normally do
I got RTK Fix more frequently today, but some of the areas where I couldn’t get RTK Fix I still could not. I do believe it performed a bit better but it’s still a struggle
I decided to try minimum elevation of 23, and Minimum Satellite signal level for navigation dBHz = 30
GNSS Receiver settings are currently
Menu: GNSS Receiver
Set measurement rate in Hz: 1.00000
Set measurement rate in seconds between measurements: 1.00000
Note: The measurement rate is overridden to 1Hz when in Base mode.
Set dynamic model: Survey
Set Constellations
Minimum elevation for a GNSS satellite to be used in fix (degrees): 23
Minimum satellite signal level for navigation (dBHz): 30
Toggle NTRIP Client: Disabled
Multipath Mitigation: Enabled
I think I’m going to bump Minimum Elevation to 25 degrees… or should I try 30degrees?
And as a scientist I know not to change more than one thing at a time… but I think I am going to change Minimum satellite signal level for navigation (dBHz) to 27
Hopefully I can get out to the farm this week to test again, but to add a 3rd variable, it will probably be a different location
One of my points I was collecting was on the edge of the forest and for about 280 degrees it was all open field… got RTK Fix from the Torch before I had SW Maps loaded and connected to the Torch… the rest of the day… off and on… but better with the Degree change
Good and bad day in the field testing. Some locations got RTK Fix quick, others Float and DPGS were the letters of the day… I was disappointed after it got RTK FIX quickly in a marginal location. I guess my forest is just too dense. Or I cranked the filters up too high.
These were the Field settings (and for the life of me I couldn’t get WEB Configure to work in the field)
Menu: GNSS Receiver
Set measurement rate in Hz: 1.00000
Set measurement rate in seconds between measurements: 1.00000
Note: The measurement rate is overridden to 1Hz when in Base mode.
Set dynamic model: Survey
Set Constellations
Minimum elevation for a GNSS satellite to be used in fix (degrees): 30
Minimum satellite signal level for navigation (dBHz): 27
Toggle NTRIP Client: Disabled
Multipath Mitigation: Enabled
I am changing to
Menu: GNSS Receiver
Set measurement rate in Hz: 1.00000
Set measurement rate in seconds between measurements: 1.00000
Note: The measurement rate is overridden to 1Hz when in Base mode.
Set dynamic model: Survey
Set Constellations
Minimum elevation for a GNSS satellite to be used in fix (degrees): 27
Minimum satellite signal level for navigation (dBHz): 25
Toggle NTRIP Client: Disabled
Multipath Mitigation: Enabled
Maybe a few days before next tests due to weather and other projects.
Question - Can you get RTK FIX with just Galileo E6 corrections?
My testing with PointPerfect hasn’t been too great due to my woods and obstructed view of the sky where I am working…
April 7, 2025 update - Decided to order an Android Tablet. I know that doesn’t help resolve GNSS Receiver issues from all the trees in my forest, but it will help me access the RTK Torch to see status messages, and easier to tweak settings in the field. The weather and other projects here are going to put Surveying on hold for at least a week. For potential RTK Torch buyers, if you are going to use it in OPEN SPACE, e.g. not in the middle of the forest like me, the results have been very good with SW MAPS and iOS using PointPerfect $8 corrections. No free NTRIP where I am at, but not sure that would help with my satellites signals getting blocked by trees. More on my testing of options 5 (Minimum Elevation) and 6 (Minimum Signal strength) over the next two weeks.
