Base-Rover Setup

Matt Johnson

Well-Known Member
5PLS
Adam, can you describe how this is done, and how it can be overridden when the base is set up on a known point? Right now I use my LS to establish a point via RTN, then swap in the T2 and send the position from the LS to the T2. When I return on another day I use the base position previously established rather than getting a fresh RTN position for it.
The base receiver must be configured to connect to RTN. It can be configured with Netview or NetBrowser. NetBrowser is the easiest method since it has a wizard for this.
 

Joe Paulin

Active Member
Adam, can you describe how this is done, and how it can be overridden when the base is set up on a known point? Right now I use my LS to establish a point via RTN, then swap in the T2 and send the position from the LS to the T2. When I return on another day I use the base position previously established rather than getting a fresh RTN position for it.
I too am interested in this - are you using the Javad Mobile Tools app to collect the the RTN point and then set up the base and radio using the app?
 

Matt Johnson

Well-Known Member
5PLS
I too am interested in this - are you using the Javad Mobile Tools app to collect the the RTN point and then set up the base and radio using the app?
Adam is just using "From Auto" in Base/Rover Setup but instead of it being an autonomous position the base receiver has a fixed position since it has RTN corrections.

upload_2017-8-10_11-6-36.png


The downside to this is that the position will only be determined by a single epoch rather than an average of many epochs.
 

Joe Paulin

Active Member
I see, thanks. A work around to the single epoch solution would be to use the Javad mobile app and the T2 to get a RTN solution and then use the app to configure and start the base/radio broadcasting? I haven't tried this yet myself.
 

Joe Paulin

Active Member
Does the base have to be configured and started by the LS for DPOS to work? Of course at the end of the day one would stop the base and download the base file with the LS.
 

Matt Johnson

Well-Known Member
5PLS
Does the base have to be configured and started by the LS for DPOS to work? Of course at the end of the day one would stop the base and download the base file with the LS.
Yes, unless you use "Recover DPOS session" to manually create the DPOS session. This would make the process more complicated than it needs to be.
 

Joe Paulin

Active Member
Yes, unless you use "Recover DPOS session" to manually create the DPOS session. This would make the process more complicated than it needs to be.
Probably negating any advantage. At the end of the day I WANT those DPOS coordinates opposed to any RTN coordinates.
 

Jim Frame

Active Member
The downside to this is that the position will only be determined by a single epoch rather than an average of many epochs.
That's a significant downside. I think I'll stick with my current method, it's not onerous and I get to assess the quality of the base point prior to starting the base.
 

Adam

Well-Known Member
5PLS
That's a significant downside. I think I'll stick with my current method, it's not onerous and I get to assess the quality of the base point prior to starting the base.
My shifts after DPOS are around .04 to .1 horizontally, vertical is usually less than .15 ft using this method. Plenty good for most of the rural boundary work I do.
 

Phillip Lancaster

Active Member
Could you not just locate a future base point using a RTN. Setup a T1/T2 over that point. Use auto positioning and store new point. DPOS will process all points except the RTN point. Then you can tell difference between RTN nail and DPOS nail. I do this every once in awhile. If its 4 hours or more base setup. I will take a DPOS position over a RTN position all the time.
 

Aaron S

Active Member
I'm in the process of testing out DPOS - a very handy feature! I have a few rapid-fire miscellaneous questions about it:

1. Do you even need a radio link between the base-rover if you plan on using DPOS? Can I simply start the T2 base station with no intentions of getting radio corrections from it (assuming it's logging data), go and occupy a point with the LS for a half hour (or whatever) and then DPOS it?

2. How long should you wait after collecting to hit the "Submit to DPOS" button? Can you do it "too soon", and will it change if you wait X number of days/hours? Is there an optimal time to wait to submit?

3. When shooting in Boundary mode, it sounds the DPOS jingle after 5 minutes and stops counting. Does it continue to log after that time if I don't accept the point? What if I think it's going to take more than 5 minutes of data to get a good point?
 

Matt Johnson

Well-Known Member
5PLS
1. Can I simply start the T2 base station with no intentions of getting radio corrections from it (assuming it's logging data), go and occupy a point with the LS for a half hour (or whatever) and then DPOS it?

yes

2. How long should you wait after collecting to hit the "Submit to DPOS" button? Can you do it "too soon", and will it change if you wait X number of days/hours? Is there an optimal time to wait to submit?

I believe most data is downloaded at the end of each hour right now. So wait at least an hour. If it appears that your closest local CORS stations are not being used then you may need to wait a day.

3. When shooting in Boundary mode, it sounds the DPOS jingle after 5 minutes and stops counting. Does it continue to log after that time if I don't accept the point? What if I think it's going to take more than 5 minutes of data to get a good point?

Data will still continue to be logged. You can view how many epochs have been collected with the GNSS Data Recording white box. You need to Accept the point for data to be saved.
 

Aaron S

Active Member
Data will still continue to be logged. You can view how many epochs have been collected with the GNSS Data Recording white box. You need to Accept the point for data to be saved.
I kind of worded my question awkwardly. I understood that you need to "Accept" the point to store any data, but I was wondering if it continues to log in the background even if the DPOS button quits counting, and continuously until you stop it. Sounds like it does. 5 minutes is apparently the minimum time to get a DPOS solution, which is why the recording counter white box continues to tick after the DPOS lights up.

This leads to my next question - why is DPOS so much better than OPUS? With OPUS you need at least 15 minutes of data, bare minimum. How can Javad do it in less time, and with quicker results?
 

Matt Johnson

Well-Known Member
5PLS
OPUS does not offer processing of base-rover data like DPOS does. Longer baselines such as those with CORS to local base require longer observation times to get good solutions. Also OPUS is GPS only where DPOS is using GLONASS too.
 
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Aaron S

Active Member
By the way, there's some kind of glitch in this message board. Matt Sibole responded to my questions too, but his reply only showed up in my email notification, not here.
 

Aaron S

Active Member
OPUS does not offer processing of base-rover data like DPOS does. Longer baselines such as those with CORS to local base require longer observation times to get good solutions. Also OPUS is GPS only where DPOS is using GLONASS too.
Right. With base-rover stuff aside though, If I were doing just a base point by itself, I would need a bare minimum of 15 minutes of data, then wait at least a day just to get a mediocre solution from OPUS. If Javad is using the same CORS stations (i.e. same baseline lengths), and just adding GLONASS, it seems pretty incredible that it can get a good solution within an just an hour or two.

Don't get me wrong - I love what the Javad system does and I think it's a way better product than what I had, I just am struggling to understand how it works so much better.
 
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