Pulse Per Second in Goose receiver

1PPS - Pulse Per Second at measurement interrupt to synchronize the IMU with Goose receiver Pulse Per Second at measurement interrupt to synchronize the IMU with Goose receiver Pulse per second is an electrical signal that has a width of less than one second and a sharply rising or abruptly falling edge that accurately repeats once per second. GOOSE has a PPS output with duty cycle of 50% There are two measures of the signal: one is the signal accuracy and the other is its precision.

1. Accuracy is how close the signal edge is to the actual UTC
2. The second measurement is the precision, which is how much the PPS signal edge changes from one second to the other. The below pictures describes, how to test the pulse per second output. The Goose GCBB board has X1002 GPIO'S Pin which can be used for external input/output by the user

• Connect the power supply, antenna cable and turn on the receiver.
• Run the ogre_console program with gps as ogre_console --gps-l1 --cold-start
• Use the oscilloscope probe and connect it with PPS output.
  • Use the oscilloscope with passive probe cable (10:1 300MHz) with a ground lead cable, as shown in the picture below:

• The 1Hz wave with 50 % duty cycle can be seen on the oscilloscope screen, below is the picture saved from oscilloscope.

This pulse can be outputted to the external IMU to synchronize it with the goose receiver.

Test setup and PPS comparison with ublox M8T:

ublox GPS based PPS is set with 50% duty cycle and connected with oscilloscope (magenta probe and magenta plot), GOOSE PPS output is also connected with oscilloscope probe (green probe and green plot) as shown below:

• The 1Hz waves with 50 % duty cycle can be seen on the oscilloscope screen, below is the picture saved from oscilloscope.