我正在尝试build立一个第一层次的服务器。 我有一个Navisys GR-701 GPS，可以发送1 PPS信号。 根据这个规格表和资料来源，我觉得我应该用ntpd来获得〜1ms的准确度。 但是，我的ntpq输出总是看起来类似于以下内容：
$ ntpq -pncrv remote refid st t when poll reach delay offset jitter ============================================================================== x127.127.22.0 .PPS. 0 l 10 16 377 0.000 -0.204 0.277 o127.127.20.0 .GPS. 0 l 11 16 377 0.000 -0.201 0.277 us.pool.ntp.org .POOL. 16 p - 64 0 0.000 0.000 0.000 pool.ntp.org .POOL. 16 p - 64 0 0.000 0.000 0.000 132.163.96.2 .NIST. 1 u 42 64 377 41.279 103.302 0.576 198.137.202.56 216.218.254.202 2 u 42 64 377 12.813 104.505 0.736 96.244.96.19 192.168.10.254 2 u 39 64 377 83.023 101.028 19.775 216.187.142.202 204.123.2.72 2 u 33 64 177 53.911 104.458 7.406 69.10.161.7 204.26.59.157 3 u 36 64 177 23.968 104.162 3.718 129.6.15.29 .NIST. 1 u 59 64 77 83.782 101.719 0.298 204.2.134.164 199.233.236.226 3 u 38 64 37 12.489 103.279 3.668 129.6.15.30 .NIST. 1 u 32 64 37 83.723 101.487 0.319 108.61.73.244 128.59.0.245 2 u 40 64 37 94.283 109.618 4.261 66.172.10.184 199.102.46.72 2 u 34 64 33 20.098 104.790 0.421 72.5.72.15 162.213.2.253 2 u 33 64 37 12.271 103.247 0.163 204.9.54.119 .CDMA. 1 u 29 64 17 61.895 102.250 1.371 198.206.133.14 58.180.158.150 3 u 60 64 3 70.588 103.281 0.451 129.250.35.250 249.224.99.213 2 u 60 64 3 12.579 102.302 0.611 216.6.2.70 195.219.14.21 2 u 61 64 3 82.862 104.402 0.366 198.55.111.50 45.79.111.114 3 u 56 64 3 22.114 104.099 0.728 216.228.192.52 207.171.7.151 3 u 28 64 3 37.095 97.609 0.214 associd=0 status=04f8 leap_none, sync_uhf_radio, 15 events, no_sys_peer, version="ntpd [email protected] Mon Oct 9 10:54:36 UTC 2017 (1)", processor="amd64", system="FreeBSD/11.1-RELEASE-p2", leap=00, stratum=1, precision=-24, rootdelay=0.000, rootdisp=1.150, refid=GPS, reftime=dda36229.ea4158ca Tue, Oct 31 2017 13:57:13.915, clock=dda36234.1c1f0bc5 Tue, Oct 31 2017 13:57:24.109, peer=28141, tc=4, mintc=3, offset=-0.200797, frequency=53.398, sys_jitter=0.276969, clk_jitter=0.014, clk_wander=0.008
ntpd.conf
tinker panic 0 # Orphan mode stratum tos orphan 12 # PPS Setup server 127.127.22.0 minpoll 4 maxpoll 4 prefer fudge 127.127.22.0 flag3 0 # GPS Setup server 127.127.20.0 mode 16 minpoll 4 maxpoll 4 prefer fudge 127.127.20.0 flag1 1 flag3 1 # Upstream Servers server time-bb.nist.gov iburst maxpoll 9 pool us.pool.ntp.org iburst maxpoll 9 pool pool.ntp.org iburst maxpoll 9 enable stats statistics clockstats statsdir /var/log/ntp logconfig =syncall +clockall +sysall driftfile /var/db/ntpd.drift restrict default kod limited nomodify nopeer notrap restrict -6 default kod limited nomodify nopeer notrap restrict source kod limited nomodify notrap interface ignore all interface listen igb0
ntpd是否真的说我的时钟在每个其他时钟的后面？ 如果是这样，为什么是这样，我能做些什么呢？