I know I am going to get blasted for this one... Can I post-process my VRS data? I have TBC (don't really know how to use it yet) if that will do it.
Post-process VRS, Why Would You Get Blasted?
Please explain what you are calling VRS.
Please explain what you call post processing.
I have used the VRS option in GNSS Solutions, I have rinexed those files and submitted them to OPUS or OPUS-RS. Is that what you mean?
If you are using VRS provided to you in the field please explain how you are storing that data.
Paul in PA
No. What is stored (at least with Trimble) are vectors. If you use the VRS style on the data collector, it stores the data as vectors from the nearest CORS (if you have the option checked to store as vectors). We also use an Intuicom RTK bridge, in which case it creates a virtual base station at a coordinate (either determined by a small GPS connected to the bridge or at a coordinate that is entered into the bridge). Then it is stored as a vector from that coordinate, the same as RTK. In fact, it is using the RTK style, it has no idea there is not a base nearby transmitting corrections.
You can, however, adjust the data if you have multiple occupations.
Post-process VRS, Why Would You Get Blasted?
Network RTK? I have one Trimble 5800 that I use to connect to various networks. I locate a lot of stuff with it, but have no way to check the results. I do take redundant shots on control, but most of the shots (curb, pavement, fence, utilities) are just out there hanging. Is there any way to post-process this data?
So can I do anything with the data derived from the CORS using the VRS style? I will Google that doohickey you mentioned...
The RTK bridge is not at all cheap. But, you can run multiple (unlimited) rovers.
I have had very good results using 'virtual' base stations for static post-processing. In Jamaica we have a VRS real time network, with an online portal for base/reference data. When I stick in an approximate lat/long coordinate for my work site, I post-process sessions as short as 1 minute to within millimeter,s or a few centimeters at worst to published coordinates. I've done this consistently, in many settings.
I find very consistent results between:
- base/rover solutions
- network RTK solutions
- network single CORS solutions
- network 'virtual base' solutions
If I'm not mistaken that what I refer to as 'virtual base' is the same as what you refer to as 'virtual rinex', I would figure the approach has a lot more use than asset mapping and other such high precision mapping applications.
I am trying to wrap my head around the use of Virtual RINEX. Are VRS just used for localizing??ÿ
Our crews observe monuments for 6 hours then downloaded 8 hour RINEX files from a real time network website and post processed them with Topcon software a week later. Is this post saying short observations will give the similar results with a VRS??ÿ
I think I understand what VRS is, I just am not sure what applications it would be best used for.
Thank you for you comments,
Dan
You've just posted to a 5 year old thread, so you may not get the attention you seek. Post what you are doing and what you think you want to do as a new thread.
Given your 6 hour observations, those observation files should be your best source to work with. VRS is most helpful when you are stuck with short observations or L1 only observations. In the past it was common to often get a better solution from short vectored L1 only data than with L1/L2 data. I do not know if that is true anymore since few people continue to use L1 only receivers. I do because I do mostly small area projects with lots of building obstructions requiring 3 or more traverse points on every project. Since I own multiple L1 only receivers that are easy to set up I set up one multi constellation receiver as base, even though I have more and spread the L1 receivers out over my traverse while I survey from point to point.
One case where a virtual RINEX file is helpful is in a gridded urban canyon environment where 2 receivers do not have a good commonality of observations with low PDOP due to obstructions. Even just one extra satellite to each of your points from an obstruction free VRS point can improve the solution and it is possible to get 2 or more. Long observations are always a good bet for the less experienced. To get the most out of short observations requires a good amount of previous experience.
Paul in PA
Is "VRS" a Trimble proprietary term??ÿ If I'm using a Leica receiver (for example) to connect to the state's CORS stations via internet (which all run on Trimble hardware/software) and do RTK stuff, am I using VRS or is there another, generic term?
It depends on what method you are using to do RTK stuff.
There are several methods of network RTK, one of them being VRS as described above by Paul. I don't think "VRS" is a trademarked term; it is not limited to Trimble products.
