Simultaneous Nadir Overpasses (SNOs) between FY3D and LANDSAT-8
TLE Epoch: 2021 4 19.  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   11:22:41   ( -71.06,-173.25) 04/20/2021   11:23:31  ( -71.08,-173.21)    2.60                50
 04/20/2021   12:13:24   (  70.94,  -5.73) 04/20/2021   12:12:59  (  70.93,  -5.81)    3.18                25
 04/23/2021   03:39:01   ( -71.08, -57.34) 04/23/2021   03:39:59  ( -71.07, -57.36)    1.51                58
 04/23/2021   04:29:44   (  70.96, 110.18) 04/23/2021   04:29:26  (  70.97, 110.13)    2.20                18
 04/23/2021   05:20:14   ( -70.25, -81.35) 04/23/2021   05:19:06  ( -70.31, -83.23)   70.90                68
 04/25/2021   19:55:20   ( -71.10,  58.56) 04/25/2021   19:56:25  ( -71.10,  58.57)    0.53                65
 04/25/2021   20:46:03   (  70.98,-133.91) 04/25/2021   20:45:52  (  71.00,-133.95)    2.48                11
 04/25/2021   21:36:38   ( -70.53,  34.14) 04/25/2021   21:35:27  ( -70.62,  33.11)   39.54                71
 04/28/2021   12:11:40   ( -71.12, 174.46) 04/28/2021   12:12:52  ( -71.13, 174.50)    1.69                72
 04/28/2021   13:02:23   (  71.00, -18.01) 04/28/2021   13:02:19  (  71.02, -18.03)    2.73                 4
 04/28/2021   13:53:03   ( -70.81, 149.61) 04/28/2021   13:51:50  ( -70.86, 149.36)   10.81                73
 05/01/2021   04:28:05   ( -71.41, -70.10) 05/01/2021   04:29:16  ( -71.32, -69.32)   29.31                71
 05/01/2021   05:18:43   (  71.02,  97.88) 05/01/2021   05:18:46  (  71.04,  97.88)    2.43                 3
 05/01/2021   06:09:25   ( -70.94, -94.66) 05/01/2021   06:08:16  ( -70.94, -94.64)    0.85                69