Hi,
A question to the GPS specialists.
I read some posts on DGPS and RTKLIB and the RTKlib over here but some things on not clear reagarding setup and usage basics.
Will this following setup work?
- Have two identical GPS units (Ublox LEA-4T) one base and the other a rover.
- Base is connected to a uC and sends its raw data to a PC (USB) which runs RTKLIB.
- Rover has same setup but has an RF modem to send the raw packets to the PC and to also receive the calculated/corrected data from PC.
Questions:
- Will this work or does one really need a real base (subscription dial in/TCP/IP etc) station to receive correction data?
- If it will work what is the update rate of the RTKLIB package, I read somewhere 1 HZ for some data but that is too slow, +4 Hz is preferred.
An accuracy of 1 meter is enough for me, maximum distance between base and rover: 300 meters?
Cheers,
Peter
Replies
Hey Peter N,
Where you able to test the setup ? If so, what accuracy level did you achieve ?
I like to do something similar, curious about your experience with this setup.
The two LEA 4T setup should work.
The uC between the base and PC may be redundant as the LEA 4T has usb outputs.
The uC between rover and RF modem may be redundant too as the LEA 4T has serial outputs too.(might need RS232 level convertor)
The LEA 4T can be run up to 20Hz on Raw data, RTKlib will process this easily with a moderate spec PC consuming 5 or 10 % cpu load.
The limiting factor on speed may be the RF modem.
For RTK the base raw data only needs outputing at 1 Hz or less even for a rover update rate of 4Hz or more.
For that reason most systems would put the RF modem on the base GPS output, to reduce the bandwidth required.
If the end result is being sent back to the rover that will reduce the bandwidth further.You might therefore consider doing the RTKLIB processing say on a PC, uC or say beagle board, on the rover, depending on your application.
Regards Anthony