RTK Frequently Asked Questions

How long does it take the AIS green LED to turn solid indicating a RTK FIXED FPS fix type?

In most cases it can take up to 5-7 minutes to achieve an RTK FIXED solution. In some instances it may take longer or never happen. A lot of the problems can be diagnosed by reading the LED sequences of each of the components. For quick reference here are common LED sequences for a normal working system while waiting for RTK.

Base Station

• Solid blue LED on power button.
• Blinking green LED above the radio connection.
• Solid green LED and blinking red LED on the radio.

Rover

• Solid blue LED on rover
• Solid green LED and blinking red LED on the radio.

AIS

• Blinking or solid red, yellow, and green LEDs waiting for RTK locks.

If one of the above sequences does not look right, see more questions below for more information.

The AIS red LED indicating RCTM messages are being received and a DGNSS fix type never turns solid. Why?

It typically takes the base station 3 minutes to finish surveying and start transmitting RCTM messages to the rover. In some cases it can take much longer than that and it depends on GPS signal strength, number of visible satellites, and surrounding electrical interference. Power off the rover and relocate it away from interference sources or tall metal structures and try again.

The AIS green LED indicating a RTK FIXED GPS fix type never turns solid. Why?

There are many factors that must be satisfied before an RTK FIXED solution can be achieved. Trying some of the following might help.

• Check the hardware and verify all the cables and antennas are installed and have good connections. Verify the LEDs on the base station, rover, and radios look ok (see first question for quick reference). Refer to the manual to get a description of the LEDs.
• Move the aircraft closer to the base station to ensure they are both seeing the same satellites.
• Do a quick flight around the base station. Moving the rover will change some of the satellite inputs and help the GPS unit resolve its errors.
• Check for GPS signal interference such as power lines and GPS testing FAA NOTAMS.

Can I fly without a DGNSS/FLOAT/FIXED GPS fix type?

The short answer is yes. The SLANTRANGE system at a minimum requires a 3D fix type and this check happens during the pre-flight checks. However if you plan to do advance analysis involving plot or trees then for workflow efficiency at a minimum it is recommended to wait for the AIS yellow LED to turn solid indicating an RTK FLOAT solution with estimated relative accuracy <0.05m.

The AIS yellow LED indicating an RTK FLOAT GPS fix type never turns solid. Why?

Trying some of the following might help.

• Check the hardware and verify all the cables and antennas are installed and have good connections. Verify the LEDs on the base station, rover, and radios look OK. Refer to the manual to get a description of the LEDs.

The green LED on my radios never turn solid. Why?

Trying some of the following might help.

• Make sure you have attached the antennas to both sides.
• If you have multiple RTK system, make sure you have matched the base station and rover radios.
• Please contact SLANTRANGE support for help if the problem persists.

The red LED on my radios is always solid when I power up. Why?

This problem is tied to improper power up of the radios and is usually tied to the batteries. Trying some of the following might help.

If you're using a DJI aircraft, verify that your battery firmware is up to date. Try another set of batteries. Check the cable between the GPS and radio for any damage.