We will be using our EMLID Reach RS2 antenna as a fixed base on top of the tower providing RTK corrections for number of researchers around the city through NTRIP.
I was wondering how much data does the RS2 need? In other words, I need to know how many Gigabytes of data I need to put in our SimCard monthly subscription given that the unit will be running 24/7.
Basically it depends on how frequently you are sending corrections. My test is I think the maximum 10hz. If you drop it down to 0.5hz you can probably be at Christian’s number.
When the dozer is grading it needs it’s position updated quite quickly. 1hz it would occasionally lose fix if it was moving fast. 10hz was so fast that it didn’t improve. 5hz never lost fix when moving fast and didn’t use quite as much data. Still 400MB/day though, hence why we got it on the wired connection.
If I was just using it for my emlid rover I would probably stick with 1hz since it doesn’t move when taking a shot.
If I was going to be flying an RTK drone, I’d say 10hz would be needed.
You can’t update the hz on the GPS dozer (they don’t offer much in the way of settings). But going with higher hz on a receiver and lower on the base would just mean it’s not getting corrections 9hz and would be trying to base the correction off older data.
I use a 20GB size for my sim account for my RS2. It takes care of my needs for 30 days, but I am in Florida, USA. If you are setting a fixed CORS you should consider getting wifi internet access at the site. If not try 20GB for a month with the GPS, Glonass and Galileo and then check your use.
I don’t know about GPS dozer but in drone mapping they use 10hz on the drone(rover) and 1hz on the base. Does the dozer move faster than the drone? I don’t think so.
By using higher data rate on the base it doesn’t have any use in your case.
In typical surveys we use 2hz or 5hz on the rover and always 1hz on the base.
In the latest firmware 28.1 I saw that the corrections were by default 0.5hz and I was wondering why emlid set this default?
A while ago, my colleague Andrew did a research about that:
Actually, RTCM3 messages are lightweight, but it depends on how many and how often you send them. Hope it will help you with calculations!
We set 0.5Hz by default for RTCM3 messages. The base is stationary, so sending data every 2 seconds is enough for centimeter accuracy, but it produces a way less load on LoRa, for instance.