Simultaneous Nadir Overpasses (SNOs) between FY3D and LANDSAT-8
TLE Epoch: 2021 4 20.  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)
 04/20/2021   11:22:40   ( -71.05,-173.22) 04/20/2021   11:23:31  ( -71.05,-173.27)    1.77                51
 04/20/2021   12:13:24   (  70.97,  -5.78) 04/20/2021   12:12:58  (  70.95,  -5.78)    2.49                26
 04/20/2021   13:03:49   ( -70.00, 163.10) 04/20/2021   13:02:43  ( -70.02, 160.48)   99.74                66
 04/23/2021   03:39:00   ( -71.06, -57.31) 04/23/2021   03:39:58  ( -71.09, -57.33)    2.62                58
 04/23/2021   04:29:44   (  70.99, 110.13) 04/23/2021   04:29:25  (  70.99, 110.16)    1.28                19
 04/23/2021   05:20:14   ( -70.28, -81.40) 04/23/2021   05:19:05  ( -70.33, -83.20)   67.60                69
 04/25/2021   19:55:20   ( -71.09,  58.59) 04/25/2021   19:56:26  ( -71.07,  58.52)    3.40                66
 04/25/2021   20:46:04   (  71.01,-133.97) 04/25/2021   20:45:52  (  71.02,-133.92)    1.97                12
 04/25/2021   21:36:39   ( -70.57,  34.08) 04/25/2021   21:35:27  ( -70.63,  33.13)   36.03                72
 04/28/2021   12:11:41   ( -71.16, 174.40) 04/28/2021   12:12:52  ( -71.15, 174.52)    4.77                71
 04/28/2021   13:02:24   (  71.03, -18.07) 04/28/2021   13:02:19  (  71.04, -18.00)    2.65                 5
 04/28/2021   13:53:03   ( -70.80, 149.64) 04/28/2021   13:51:51  ( -70.82, 149.30)   12.83                72
 05/01/2021   04:28:04   ( -71.39, -70.07) 05/01/2021   04:29:16  ( -71.28, -69.39)   27.57                72
 05/01/2021   05:18:43   (  71.06,  97.82) 05/01/2021   05:18:45  (  71.06,  97.91)    3.11                 2
 05/01/2021   06:09:24   ( -70.93, -94.64) 05/01/2021   06:08:15  ( -70.95, -94.62)    2.81                69
 05/03/2021   20:44:29   ( -71.68,  45.35) 05/03/2021   20:45:38  ( -71.56,  46.96)   57.93                69
 05/03/2021   21:35:02   (  71.03,-146.20) 05/03/2021   21:35:13  (  71.02,-146.28)    3.40                11
 05/03/2021   22:25:44   ( -70.96,  21.25) 05/03/2021   22:24:42  ( -70.97,  21.28)    1.75                62