Simultaneous Nadir Overpasses (SNOs) between FY3D and NPP
TLE Epoch: 2019 12 11.  Predictions up to the next  14.0 days:

     Date     Time(FY3D) FY3D Lat/Lon Date Time(NPP) NPP Lat/Lon    Distance(km)  Time Diff(sec)
 12/24/2019   08:57:44   ( -81.26, 164.33) 12/24/2019   08:56:28  ( -81.26, 164.48)    2.51                76
 12/24/2019   10:39:14   ( -81.27, 138.61) 12/24/2019   10:37:59  ( -81.26, 138.66)    0.78                75
 12/24/2019   11:29:59   (  81.27, -54.19) 12/24/2019   11:28:44  (  81.27, -54.18)    0.22                75
 12/24/2019   12:20:44   ( -81.27, 112.90) 12/24/2019   12:19:30  ( -81.27, 112.84)    0.96                74
 12/24/2019   13:11:28   (  81.27, -79.52) 12/24/2019   13:10:14  (  81.27, -79.61)    1.53                74
 12/24/2019   14:02:14   ( -81.28,  87.18) 12/24/2019   14:01:01  ( -81.28,  87.02)    2.69                73
 12/24/2019   14:52:57   (  81.27,-104.85) 12/24/2019   14:51:44  (  81.27,-105.04)    3.29                73
 12/24/2019   15:43:41   ( -81.26,  62.63) 12/24/2019   15:42:28  ( -81.26,  62.75)    2.17                73
 12/24/2019   16:34:27   (  81.27,-130.57) 12/24/2019   16:33:14  (  81.27,-130.48)    1.58                73
 12/24/2019   17:25:11   ( -81.27,  36.91) 12/24/2019   17:23:59  ( -81.27,  36.93)    0.44                72
 12/24/2019   18:15:56   (  81.27,-155.90) 12/24/2019   18:14:44  (  81.27,-155.91)    0.18                72
 12/24/2019   19:06:41   ( -81.27,  11.19) 12/24/2019   19:05:30  ( -81.28,  11.11)    1.30                71
 12/24/2019   19:57:25   (  81.27, 178.77) 12/24/2019   19:56:14  (  81.27, 178.66)    1.93                71
 12/24/2019   20:48:10   ( -81.27, -14.14) 12/24/2019   20:47:00  ( -81.28, -14.32)    3.03                70
 12/24/2019   21:38:55   (  81.28, 153.05) 12/24/2019   21:37:44  (  81.27, 153.23)    2.93                71
 12/24/2019   22:29:38   ( -81.27, -39.08) 12/24/2019   22:28:28  ( -81.26, -38.97)    1.83                70
 12/24/2019   23:20:24   (  81.27, 127.72) 12/24/2019   23:19:14  (  81.27, 127.79)    1.18                70
 12/25/2019   00:11:08   ( -81.27, -64.80) 12/25/2019   00:09:59  ( -81.27, -64.79)    0.10                69
 12/25/2019   01:01:52   (  81.27, 102.79) 12/25/2019   01:00:43  (  81.27, 102.75)    0.57                69