Community Forum

I need help with fix solution

(Mohamed) #1

Greeting every one
I have two reach rs+ devices, my problems I can’t get fix solution all the time single, but when I used it with our local ntrip it is fine and give fix solution.
Surveying done at open place and clearly sky
My location Saudi Arabia Medina city Lat= 24.426621 Long =39.611174
Attached my settings and system reports

fix solution with our local ntrip



SystemReport rover.zip (138.9 KB)
SystemReport base.zip (398.6 KB)

base_201901160535_RTCM3.zip (1.3 MB)
raw_201901160505_UBX.zip (416.5 KB)
raw_201901160536_UBX.zip (6.2 MB)
raw_201901160751_UBX.zip (126.2 KB)
solution_201901160535_LLH.zip (701.6 KB)

(Mohamed) #2

I tried many different settings but no fix. I recognized that QZSS and SBAS not available in my area.

Thank you for your response time


You need base set with average singel, not average fix coordinates.
Try and see if that helps

(Mohamed) #4

Thank you very much, I will feed you back

(Mohamed) #5

It worked and my rover give fix solution. But I need high accuracy and precision that can’t achieved when base set with average single.


There are few options you can do.
1.place base over a known point and fill in coordinates manually
2.average FIX and use ntrip and feed base with correction via “correction input” menu

(Mohamed) #7

why there is no fix solution when base set with (average fix) ?


Because you need to feed base with correction data to get fix and if it doesn’t have fix, it would not average it.

(Mohamed) #9

So when base set with average single I can’t get high accuracy ?


No. Just average a single solution. +/- 1m ish for base.
Rover of course, relative to base will be accurate.
But no absolute accuracy unless you have set base with accurate coordinates.

It should be well explained in the doc section.

(Mohamed) #11

So, float is better
Thanks, for your time and help

(Michael Lambert) #12

If you didn’t try average single how do no that is not accurate? A 10 to 15 minute observation should be plenty accurate. I always prefer a known point, but understand that is not always possible. Sometimes you just have to settle for high-precision relativity and then transform the coordinates to other known data on the back end.

(Timd1971) #13

FLOAT is better than SINGLE, but FIX is better than both FLOAT & SINGLE and BEST.

But… in order to use FLOAT for your BASE, you need to use NTRIP in addition, so might as well set as FIX and use NTRIP if <15km for your base. Otherwise FLOAT & NTRIP <100km, but again, you’ll only get 1.0m accuracy, so no point using FLOAT & NTRIP if you can use FIX & NTRIP and get 7mm+1mm/km accuracy.

Or if you have a KNOWN POINT, that is obviously BEST.

As the docs state, no matter which method you choose, the relative position of the ROVER will always be cm-precise. So your actual accuracy will always be determined by the accuracy of the BASE. So if you can set your BASE on a KNOWN POINT, that is absolute BEST.

(Mohamed) #14

I tried average single before. And I thought that if base set with average fix I can get +/- 1cm accuracy without a KNOWN POINT or NTRIP :joy: :joy:

(Mohamed) #15

I hope that Reach Rs be came more efficiency and give us high accuracy without a KNOWN POINT or NTRIP just like Trimble, Leica, Topcon …etc

(Michael Lambert) #16

So if you tried it and what did you check against that told you you weren’t accurate?

As for comparable performance, that’s not going to happen at this price point and single frequency.

(Timd1971) #17

I think it’s because he gets a FIX using NTRIP, but he wasn’t clear about the accuracy if NOT using NTRIP or a KNOWN POINT.

Wishful thinking for a future multi-freq product from Emlid… I would assume that is in the works and cannot wait also! I could see Emlid making that possible even at double cost of the current RS+ ; )

(Mohamed) #18

Against a KNOWN POINT.

(Michael Lambert) #19

So you can set up your base on that known point?

(Hunter) #21

Is it possible to calibrate base with a rover collection point or perhaps this is a feature that can be added? Two reach units, base and rover running in RTK mode. You setup base like Mohamed and start surveying. Your base coordinate can be set as you wish regardless of accuracy in this case. However, during surveying you hit a known point with your rover. Occupy the point for given amount of time and then input the known point. The software could then adjust parameters and base coordinate accordingly. I have found many of my known points are not in locations I would prefer to set my base at unoccupied for a long period of time…