I have been dabbling with GPS modules for a long time but recently got my first RTK board. I got the LG290P Breakout board and just got my first Fixed RTK lock yesterday using QGNSS.
The nearest free NTRIP server to me is about 100 miles away and the GOV and private casters are fairly expensive.
Am I correct in thinking I can get another RTK board and decent antenna and make my own base station? I know the answer is yes, but do I still need to use NTRIP with a mount point for both?
Also relevant is that at this time I am just a guy playing with the tech aspect of GPS and currently my only goal is to see âFIXED RTKâ displayed in software and I have no practical use at this time other than that.
I have a Tech Blog and it is just good subject matter for me to write about. Thatâs the extent of the usefulness of an RTK lock.
Still I think picking up an RTK Postcard with the LG290P chip and antenna will be a one time cost that rivals an annual subscription and I am willing to spend the money to do that.
Since you have a Tech Blog, maybe take it one step further ?
Install the proposed PostCardâs antenna in a permanent location (with WiFi) and operate a free Base Station (on RTK2Go for example). Youâll have one 0 miles away from now on, instead of 100 miles
You can help show others how cheap and easy it is. Plenty of folks here to help ya with commissioning the Base if you need it.
Thank you! I didnât realize I could add a base station to RTK2Go. A quick google says I have to set it up as âSurvey Inâ. While I can probably figure it out, some hand holding might be necessary. I think Iâll give it a shot.
One more quick question. Do I HAVE to have a survey type antenna or can I get one of those L1/L2/L5 active antennas like this one.
Welcome @JohnEH ! Congrats on the first RTK Fix. Thatâs big. By all means scratch the âwhat ifâ itch! A Postcard + UFO antenna is a great base. Weâre consolidating and updating our docs, but I recommend you have a look at these docs to get the Postcardâs location for a permanent base. Weâve got a few versions of this doc, but the goal is to capture ~12 to 24 hours of raw satellite data, cook it down using CSRS or OPUS, all to get the exact location of your antenna. From there, do note that the RTK Everywhere firmware on the Postcard can transmit to up to 4 casters (4 simultaneous NTRIP Servers). Our SparkFun HQ base station sends RTCM to RTK2Go (for our own rover consumption), Emlid (for when RTK2Go has problems), and Onocoy (because I curious if I can ever convert their funny tokens into actual beer).
If you decide to use RTK2Go, youâll need to âregisterâ your base - itâs free, you just have to fill out a form asking for a certain base mount point / name.
The GNSS All-Band High Precision Antenna - 5m (SMA) antenna is great! Itâs generally used for automotive applications, but works very well. For most of my installs, I use a UFO antenna such as the SPK6618H. Itâs slightly better but really, use whatever youâve got. Just make sure itâs got as clear view of the sky as possible, and that itâs anchored well, so that it canât be easily bumped.
Thanks for that info! Iâm wild guessing that Sparky means that you are Sparkfun so all the better that my GNSS dealer answers questions. Regarding being my dealer, I think I own 5 or 6 other Sparkfun modules and I have blogged about most of them and brag on you guys for being an authentic source of u-blox chips. So many counterfeits out there.
I had just bought the NEO-F10N and realized I needed to make the jump to RTK. I think itâs pretty much a done deal that Iâll order the LG290P postcard here today or tomorrow.
Itâs probably poor form to link to my blog here but since you have my registration info it is just my last name dot com.
Iâll read those docs you posted before I order. Thanks again so much for a few years of GPS learning and fun.
Couple more questions. If I get the portability module for the RTK postcard do I populate every pin on both devices edges? One side has 9 and the other 10. Do all 19 get connected to each other? Any preference as to which board gets female or male headers?
For headers it just depends on how youâd prefer the board to mate, either side being M/F is fine (just ensure theyâre oriented to mate properly, facing one another when assembled)
The headers being different is on purpose to help prevent assembling them 180 degrees off; with 9 & 10 you can only combine them in one way after soldering on headers
Youâd just need 1x of Male and 2x of Female; the males are easier to splitâŚsimply use some snips. For the Female youâll need to shorten one by one pin, I find snips are usually the best thing for this as well (if you happen to have a 3D printer the super-sharp ones that comes with them are great!)
Thank you! I just ordered the Postcard, the Portability board, battery and 40 pin header (male) I have the female headers here already.
On another note I just emailed support and wanted to add a LiPo charger to my order. I went to order it but the shipping cost doubled the cost. The first order has free shipping.
Hello, if Iâm understanding correctly, you want to achieve RTK/PPK-level accuracy (1-2cm) without access to a continuously operating reference station (CORS) via NTRIP. You can absolutely use two RTK GPS modules as a base and rover, BUT you will still not have centimeter-level absolute accuracy.
The base and rover will communicate and the rover will know its location to within 1-2cm (depending on fix quality, board quality, etc,) based on RTCM correction signals from the base. The trouble is, the base still doesnât know its precise location any better than it did. Your rover position is now highly accurate relative to the base, but absolute accuracy is still no better than 1m or so.
You will need either NTRIP corrections OR a known location. If you have a property marker or other benchmark with a survey-quality location known to you, that becomes your link to absolute geolocation accuracy. That location gets programmed into your base via whatever software youâre using. Now, when the base sends RTCM correction signals to the rover, you get centimeter-level relative AND absolute accuracy.
As others have said, you can also use that base as your own CORS. Donât ask me exactly how to implement that; I know the GIS theory but not the tech side so well, lol. Hope this helps!
It helps! Thank you. I have everything for making the base station I just need to figure out where to mount the antenna so that it is in the clear and the computer running it can get power.
Ideally I would just love to use NTRIP connection data with my rover but there are no base stations near me that are cheap or free. Iâm not dropping $400 a year for me not having a practical use for all this. Iâm just learning, blogging, and at best might survey my property because Iâm actually not sure where the property lines are. 1.5 acres wooded in the Croatan National Forest and a creek running through the property. Neighbors are cool and no issues there but I just want to do it to see if I can.
I think Iâll give it a shot.