MMWCAS-DSP-EVM: How do I synchronize system time and hardware time with network time?And how to parse timestamp?

Now, I use MMWCAS-DSP-EVM and MMWCAS-RF-EVM(AWR2243), and I find some information about the timestamp from official MatlabExample.(as shown below)

Then, I follow the information and try to parse every radar frame's timestamp. The reults are shown below:

the master0000_idx.bin file

the first frame's timestamp:             1503228999

the second frame's timestamp:       1503278960       (49961 differs from the previous one)

the third frame's timestamp:            1503328950       (49990 differs from the previous one)

the forth frame's timestamp:            1503378972       (50022 differs from the previous one)

Because I set the FrameInterval as 50ms, the difference between timestamps looks accurate. But there exits two problems:

1. The timestamp is made up of ten digits and is accurate to us. What format is it? Typically, UNIX time consists of 10(accurate to s), 13(accurate to ms), or 16(accurate to us) digits.

2. The timestamp is inconsistent with the network time, How to fix it?Since we need to use the millimeter-wave radar in conjunction with other sensors, we need to get a true timestamp for each frame.