I have couple questions regarding your GPS RTK kits.
To give some context, I work mostly in France, sometimes in remote areas with no cell coverage. So I’m interested in getting 2 RTK Facet for a base+rover configuration.
Depending on the location I work, I need to set up the base antenna a bit far (>1km, in hilly/forested areas) from where I need to take measurements with the rover. I found this LORA antenna (https://www.sparkfun.com/products/20029) which seems to be what I’m looking for, but it’s out of stock.
Any recommendation for alternatives, or update on when it’ll be available again ?
I’m also interested in getting a Surveyor Express Plus because I sometimes work in forest where I need to track my position about every second (or so). In this case, losing GPS signal can be really problematic. Would the IMU in the Express Plus do the trick for this kind of survey ?
I use two Facets in hilly and heavily forested woods with no cell service. I do property surveying and need the RTK accuracy.
I use RFD900x 900MHz radios, they are 1 watt and I bought them before SparkFun released the LoRaSerial radios. I bought a longer antenna cable and a better antenna (SparkFun) for the base and I raise the antenna up high.
This setup works very well as long as I’m not too far from my base. Conditions vary (leaves, hills, pine trees, etc.) so it’s hard to predict the exact distance I’ll get on a given day.
I generally need to have a line of sight between the two radios (base and rover). If I rove far down behind a hill, I loose the radio connection. The radios will transmit through the trees but after a couple thousand feet I begin to lose the radio.
I recently got a Facet L-Band and I am still testing it as my rover. You might consider the Facet L-Band model. You don’t need to set up a base or use radios between a base and rover.
toeknee:
I use two Facets in hilly and heavily forested woods with no cell service. I do property surveying and need the RTK accuracy.
I use RFD900x 900MHz radios, they are 1 watt and I bought them before SparkFun released the LoRaSerial radios. I bought a longer antenna cable and a better antenna (SparkFun) for the base and I raise the antenna up high.
This setup works very well as long as I’m not too far from my base. Conditions vary (leaves, hills, pine trees, etc.) so it’s hard to predict the exact distance I’ll get on a given day.
I generally need to have a line of sight between the two radios (base and rover). If I rove far down behind a hill, I loose the radio connection. The radios will transmit through the trees but after a couple thousand feet I begin to lose the radio.
I recently got a Facet L-Band and I am still testing it as my rover. You might consider the Facet L-Band model. You don’t need to set up a base or use radios between a base and rover.
Thanks for the feedback. I’ll look into this radio.
As for the L-Band, it seems interesting to get rid of radio and all, but I’m not sure I want to invest in a system requiring a yearly subscription (Sparkfun mentions 500$). Also I work in countries outside Europe and US, so the only option there is the Base+rover configuration. But I’ll keep that in mind…thanks again
liaifat85:
The LoRa antenna you mentioned, the SparkFun LoRa Antenna - 915MHz (P/N: WRL-20029), is designed for LoRa communication and might not be suitable for RTK corrections.
The Surveyor Express Plus is a GNSS RTK board with built-in IMU. It can help provide more stable position estimates in challenging environments
Thanks for the reply. The description of the antenna set on Sparkfun’s website says “The radios in the LoRaSerial Kit support simple point-to-point communication as well as multipoint broadcasts. Multipoint broadcasting makes this kit ideal for GNSS RTK and many other geospatial scenarios where one device needs to produce and delineate data that many other devices might need to utilize.”
So I assuming they are suitable for RTK corrections…but if they’re not available, the question is irrelevant anyway
This is the antenna I use and it works great with both the 100mW 900MHz Holybro radios I purchased from SparkFun and the RFD900x radios I purchased elsewhere.
FYI I had to make my own cables to connect the RFD900x to the Facets. I bought a handful of various drone telemetry cables and frankensteined what I needed. I was very careful to not let the magic smoke out of any components.
spasquet:
As for the L-Band, it seems interesting to get rid of radio and all, but I’m not sure I want to invest in a system requiring a yearly subscription (Sparkfun mentions 500$).
I’m working on a large scale project that ended up selecting the Facet L-Band as the primary hardware.
The recurring Point Perfect Subscription price is always questioned by interested parties, and reasonably so.
We concluded the benefits far outweigh a ~ $40/month subscription.
We don’t need to deal with the typical drama and costs associated with a local RTK solution at each project site.
With network RTK (RTN)- you are dealing with Cellular Service, reference frames changing between projects/Bases, etc.
Worst Case Scenario: If a Facet-LB is ONLY used 1 time per month, we can easily justify that $40 expense with the instant productivity when that Unit hits the ground and starts logging RTK from the PP L-Band Correction, even if that site is 200 miles from the previous project site.
I’ve used RTK and RTN for years and this isn’t a “knock” against either.
But for many applications, Point Perfect L-Band Corrections make a lot of sense.
I consider the Facet-LB being a decent attempt to “future-proof” our investment in hardware, as RTK and RTN are still available with it.
