MAVROS Wall-Clock

Hi all,

I’m implementing guidance algorithms in SITL and on real drones.
One of the algorithm’s input is a wall-clock, updating in at least 5 [Hz]. I saw some options to inject time into the algorithm but I’m bit confused:

  1. ROS topic /clock only working in seconds, so 1 [Hz] not fast enough, any way to increase it?
  2. /mavros/time_reference I didn’t understand the Sec and Nsec, there are some docs about this topic?
    the secounds are 10^9 numbers and the Nsec looks like sine wave when I plot it with matlab.

Thanks in advance,