How can I test IRIG-B'a accuracy using Labview

[JYC]

Hope there is such platform.  We try to build one if neccesary.   We need tiem accuracy as well as the IRIG-B waveforms. Any suggestion ?

[jspaarg]

It all depends on what you need to check.

PPS contains only timing info, IRIG contains time and timing.

Is the IRIG that you are getting digital or AM?

I will assume that this is standard IRIG B, which means that the timing accuracy is derived from the zero crossing of the analog signal, or the rising edge of the digital.  You will need some kind of high speed data acquitision and trigger.

Keep in mind that EVERY zero-crossing is on-time, they are just not at the PPS.  That is your zero crossings occur on-time every 1 ms.

After you get your array from your data acquisition, it is a simple matter to look for zero crossing on analog or state transition on digital.  You can use your timebase to verify the accuracy.  Is this supposed to be a product, or a Lab Instrument?

[JYC]

Just a lab setup

[jspaarg]

I am just getting started with LabView and related stuff, but I am sure that NI offers Hi-speed DAQ cards.

You will need at least three channels: GPS-ref PPS, GPS-ref IRIG, GPS-test PPS.

Sample the GPS ref PPS until you get a rising edge.

Once you have the first one, configure the system to fire in 998 ms (or so) and acquire data on all three channels for 3 ms (or so)

You can analyze your arrays and determine your accuracy.

Fire again.

Lather rinse repeat