Looking for some basic help/explanation of post processing (NRC)

Hope you can help. I submitted a rinex file to Natural Resources Canada (NRC) for post processing and got the following message back:

raw_201711172127.obs
Warning : Your GPS RINEX data will be processed now. A combined GPS, GLONASS solution will be performed once the necessary GLONASS products are available.
Error : CSRS-PPP online was unable to process your submitted RINEX file. Most likely causes are not enough epochs or missing data types.
raw_201711172127.gnav Error : Not a valid RINEX observation file.
raw_201711172127.hnav Error : Not a valid RINEX observation file.
raw_201711172127.nav Error : Not a valid RINEX observation file.
raw_201711172127.sbs Error : Not a valid RINEX observation file.

This is the first time I sent a file in for processing and have no background in this field. What does all of this mean? What do I need to do.

Thanks of any help/suggestions you can make.

Just a guess, but I would check the supported RINEX versions first. Maybe the service can only use RINEX 3?

It can only use rinex 2.1, I believe.
Jim

I’ve tried submitting RINEX files to a number of different online services, attempting to submit in the proper RINEX version, and never been successful. It may be that these services require a two-frequency RINEX file, and the Reach RS is single frequency. I wound up downloading *.17o files from a CORS service, and using those with RTKLIB_Post to get a position.

Right now the biggest void in information is how to Post Process. I would dare say that if anyone needs help setting up the Reach RS / Reach modules then they certainly do not have a clue how to post process (including me). There are a few likely scenarios when using the Reach units:

  1. You are using one Reach unit using an NTRIP caster for RTK precision (internet connection required) for general survey work.

  2. You are using 2 Reach units (one base and one rover). Using this there are 2 options:
    a. Your base unit is getting corrections via NTRIP and the rover (ie Reach on Drone, second RS unit, etc) is getting corrections from the base via LoRa radio. This scenario will product RTK precision.

  3. You are using 2 Reach Units (RS or Modules) and there is no internet or you have no NTRIP service. There will be no RTK and you will have to post process for accuracy.

This is where the big problem is for newbies. I think there will be many drone pilots seeking to get into Drone Mapping and end up with Reach units but until you understand how post process you really are stuck at level 0. You simply can not move on to using Pix4D or other software if you can not post process.

So hopefully there will be someone who (even for profit) makes a complete (and quality) video (or video series) on how to post process and why you are doing the various steps you are doing. I have learned how to do alot of things in my life but understanding the complete Survey process for drone mapping has been the steepest learning curve I have encountered. Primarily because there is no available videos or teaching material for post processing that teaches from the stand point that the students know absolutely nothing about it and starts from Level 0 then goes up from there.

I think sooner or later someone will make this video. They can even put it on a paid video site and sell it because guys like us have to learn it order to succeed in this field.

Hi,

Can you please post the compressed RINEX observation file (no need to attach the ephemeris) so that we can see where is the problem?
I have submited several times emlid originated RINEX to NRCan PPP and it works just fine for me so I’m assuming you are doing something wrong.

Isaac

As a processing newbie, I agree. Processing is a dark hole for the uninitiated. I would pay if someone could turn on the light for me. Thanks for the scenarios. Some are new to me and I look forward the exploring them.

Any chance to see the RINEX file so that we can at least guide you through submitting files to NRCan PPP?

Thanks for the offer of assistance. I don’t have access to the files right now. As soon as I do, I’ll send them. Again, thanks.

Sounds good

If you come across anything please let me know. I now have a good understanding of setting up the Reach RS units and entering the NTRIP caster stuff. That in and of itself was a challenge to finally say “I finally understand it”. But now that I have that down pat, the post processing is just a big blur. There is one of the pro users here on the forum https://www.youtube.com/channel/UCck52AWmU1Vo9HXMHxJuH3A has been VERY helpful to me but I need a teaching style video on the topic of post processing with explanations of why everything is done. When I get this under my belt I am off to the races!! So keep me posted and if I ever get to that point without the help of a video, then I will make one myself :slight_smile: So either way, let’s keep each other posted and someday soon I hope we lookback and smile on the progress made.

These guys made really good videos on setting up the Reach RS units (and same would apply to the Reach module). https://www.youtube.com/channel/UCKKI6ezzKMOEtlG6vQpIMcg

I sent them a message and suggested that they make a good video series on doing Post processing and sell it on udemy or something similar. But I have not heard back on that.

Troy at http://www.guardmy6.com/ has good training videos on Pix4D and other stuff but I am not sure if he has plans on doing videos specifically on Post Processing Reach logs. I will send him and email and ask.

I really want to learn this stuff and trying hard to peak someones interest!!

Hi Isaac,
As I said I’m new to all this. I believe this is the file you requested. At first impression it seems that NRCan PPP is easy to use, if I find out what I did wrong. Thanks for helping.

https://drive.google.com/file/d/1E7zkF98F7nO5WtAA8oKX6u-GJbrnxe_i/view?usp=sharing

Ross

The videos on setting up the Reach RS units contain a lot of useful and basic information. This is the type of information the Emlid folks should be preparing and offering. The on-line “manual” lacks important details, is frequently unclear, and hard to follow. On the other hand, I found Emlid’s on-line support to be exceptional and willing to go above-and-beyond to help. The on-line support was truly outstanding!!!

[quote=“datafromdrones, post:12, topic:8002, full:true”]

Hi Isaac,
As I said I’m new to all this. I believe this is the file you requested. At first impression it seems that NRCan PPP is easy to use, if I find out what I did wrong. Thanks for helping.

https://drive.google.com/file/d/1E7zkF98F7nO5WtAA8oKX6u-GJbrnxe_i/view?usp=sharing

Ross

Hi Isaac,
As I said I’m new to all this. I believe this is the file you requested. At first impression it seems that NRCan PPP is easy to use, if I find out what I did wrong. Thanks for helping.

https://drive.google.com/file/d/1E7zkF98F7nO5WtAA8oKX6u-GJbrnxe_i/view?usp=sharing

Ross

Hello Ross

Are you .zip (ing) your file before uploading. I just zipped your file and it uploaded ok to NRC. Whoops that came back with an error after processing.

So I used rtkconv_emlid_b27.exe to convert to rinex 2.11 and then zip that file. The 1st upload gave an error so without going off that screen, re upload the file and it goes thru and processes ok. I have had to do it this way for my files also not sure why but works for me.

Hope this helps
Jim

Hi - I am getting the same error when I submit to NRC … similar error to above played around with settings, and this is the fourth attempt. Can somebody look at my file an figure out what I am doing wrong?

Thanksraw_201711211424_RINEX-2_11.zip (4.9 MB)

Hi Ross,

The problem with your RINEX file is that the header indicates that the RINEX contains L2 observables but your recorded epochs only contain L1 data (as of today Emlid products only provide L1 data).
If you used RTKlib to convert from U-blox format to RINEX you will have to disable de L2 checkboxes and reexport to RINEX, ensuring that the hader only indicates the four L1 observables (C1, L1, D1, S1 but no C2, L2, D2, S2)

Hi David,

The same issue I mentioned to Ross is applicable to you.

Hi Isaac - thanks for that explanation. Since I used ReachView (using the pull down box in logging) to select Rinex 2.11, and didn’t use RTKlib, is ReachView inserting the L2 flag in the header? How should I proceed?