Simultaneous Nadir Overpasses (SNOs) between FY3D and LANDSAT-8
TLE Epoch: 2021 4 12.  Predictions up to the next  14.0 days:

     Date     Time(FY3D) FY3D Lat/Lon Date Time(LANDSAT-8) LANDSAT-8 Lat/Lon    Distance(km)  Time Diff(sec)
 04/12/2021   10:33:42   ( -71.02,-160.98) 04/12/2021   10:34:10  ( -70.99,-160.99)    3.28                28
 04/12/2021   11:24:25   (  70.91,   6.53) 04/12/2021   11:23:37  (  70.89,   6.51)    1.50                48
 04/15/2021   02:50:01   ( -71.03, -45.06) 04/15/2021   02:50:36  ( -71.05, -45.02)    2.33                35
 04/15/2021   03:40:44   (  70.92, 122.45) 04/15/2021   03:40:03  (  70.95, 122.46)    3.40                41
 04/17/2021   19:06:21   ( -71.04,  70.85) 04/17/2021   19:07:04  ( -71.04,  70.85)    0.31                43
 04/17/2021   19:57:04   (  70.93,-121.64) 04/17/2021   19:56:31  (  70.94,-121.67)    1.92                33
 04/20/2021   11:22:41   ( -71.05,-173.23) 04/20/2021   11:23:32  ( -71.03,-173.29)    3.00                51
 04/20/2021   12:13:25   (  70.99,  -5.81) 04/20/2021   12:12:58  (  70.98,  -5.73)    2.96                27
 04/23/2021   03:39:01   ( -71.07, -57.31) 04/23/2021   03:39:59  ( -71.08, -57.35)    1.53                58
 04/23/2021   04:29:44   (  70.95, 110.20) 04/23/2021   04:29:26  (  70.96, 110.12)    3.18                18
 04/23/2021   05:20:15   ( -70.29, -81.40) 04/23/2021   05:19:06  ( -70.32, -83.22)   68.09                69
 04/25/2021   19:55:20   ( -71.08,  58.60) 04/25/2021   19:56:25  ( -71.11,  58.59)    3.43                65
 04/25/2021   20:46:04   (  71.01,-133.98) 04/25/2021   20:45:52  (  71.00,-133.95)    2.13                12