Autonomous Base Accuracy comments

[Nate The Surveyor]

When I first got the T-2 Javad LS combo, I set the RADIO up first, then the T-2, and the Horiz SHIFT from autonomous to SPC was typically about 5 ft. Vert was around 10 or more feet.

Now, I set the T-2 up FIRST, turn it on, then the radio.

This gives the T-2 a little more time to "Find Itself".

Now, the Horiz shift is nearly always less than 3 ft, and the Vert is usually less than 6 ft.

I think it also fixes FASTER when the base shift from autonomous to SPC is smaller.

Just a comment from a user.

Nate

 

[Jim Campi]

Nate, you bring up an excellent point.

I could be onsite for hours doing something other than surveying. If I set up the T2, power it on, come back several hours later and power up the radio and LS - will that result in a more accurate autonomous position than setting up all system components at the same time?

No static survey in the first scenario. Power up T2 on the tripod and walk away.

 

[Steve Douty]

So... does anyone have an answer?

 

[Matt Johnson]

I've read that is estimated that every 10 m of error in the base station coordinates introduces one part per million error in the baseline vector. I don't see there is any advantage in leaving the base station on a long time before starting the base as it does not take that long for it to acquire satellites. You could enable SBAS positioning on the base for a little better base position however.

 

[Jim Campi]

Thanks Matt. Is SBAS an upgrade or do all T2 units w/ the GLONAS/RTK option have that capability?

 

[Matt Johnson]

You should have the option already, you just need to change the Position Computation Mode to "wd" and enable SBSS tracking in NetView:

Then you should see a DGPS solution:

Note that these parameters are not sticky so if you clear the NVRAM they will be lost.

 

[Jim Campi]

Thanks Matt.

It seems I clear NVRAM frequently, can we enable SBAS in the field with JMT?

 

[Matt Johnson]

Thanks Matt.

It seems I clear NVRAM frequently, can we enable SBAS in the field with JMT?

With NetBrowser you can.

 

[Matt Johnson]

We decided to send these parameters to the base automatically when connecting to the base in Base Rover Setup so in the future everyone should have a DGPS solution when starting the base.

 

[Matt Johnson]

The test version of J-Field will now display when the base has a CDF position:

 

[Nate The Surveyor]

This is the kind of service to dream about.
Somebody has an idea, somebody builds off it, adds to it, and a week or two later.... Bam! It's being implemented!

 

[John Thompson]

A bit of a hijack, but that Proposed Base Position screen reminded me...I think that in addition to being able to choose base coordinates From List, Enter, and From Auto, there ought to be a Nearest or maybe a From Map. Whenever I see that screen, I'm almost always very near the point I want to use for a base, but I may not remember the point name. It would save a few clicks even if I remember it.

 

[Shawn Billings]

When you recall from list, hit the filter button and sort by distance from current position. A quick nearest point button and from map button would be nice.

 

[Clifton Keith]

When you recall from list, hit the filter button and sort by distance from current position. A quick nearest point button and from map button would be nice.

Me think so too!

 

[Nate The Surveyor]

If you go back to COGO, and DPOS, you will see a list of your prev base files. If you are setting up your base on a prev base site, this works fine. But, if you are setting it on a point in the file, but that has not been a base before, then well, not so good. So, what Shawn says, is good.
N