Simultaneous Nadir Overpasses (SNOs) between NOAA-21 and FY3D
TLE Epoch: 2022 12 9.  Predictions up to the next  14.0 days:

     Date     Time(NOAA-21) NOAA-21 Lat/Lon Date Time(FY3D) FY3D Lat/Lon    Distance(km)  Time Diff(sec)
 12/09/2022   03:28:42   (  81.21,  69.42) 12/09/2022   03:27:59  (  81.20,  69.37)    0.99                43
 12/09/2022   04:19:17   ( -81.20,-123.14) 12/09/2022   04:18:44  ( -81.20,-123.12)    0.30                33
 12/09/2022   05:10:02   (  81.20,  44.17) 12/09/2022   05:09:30  (  81.20,  44.27)    1.82                32
 12/09/2022   06:00:37   ( -81.20,-148.39) 12/09/2022   06:00:15  ( -81.20,-148.21)    3.00                22
 12/09/2022   06:51:22   (  81.20,  18.91) 12/09/2022   06:51:02  (  81.20,  18.79)    2.04                20
 12/09/2022   07:41:57   ( -81.20,-173.64) 12/09/2022   07:41:47  ( -81.20,-173.69)    0.89                10
 12/09/2022   08:32:42   (  81.20,  -6.34) 12/09/2022   08:32:33  (  81.20,  -6.30)    0.74                 9
 12/09/2022   09:23:18   ( -81.21, 160.72) 12/09/2022   09:23:19  ( -81.20, 160.83)    1.87                 1
 12/09/2022   10:14:02   (  81.20, -31.60) 12/09/2022   10:14:05  (  81.20, -31.78)    3.15                 3
 12/09/2022   11:04:37   ( -81.19, 135.85) 12/09/2022   11:04:50  ( -81.20, 135.74)    2.08                13
 12/09/2022   11:55:22   (  81.19, -56.85) 12/09/2022   11:55:36  (  81.20, -56.87)    0.58                14
 12/09/2022   12:45:58   ( -81.20, 110.22) 12/09/2022   12:46:22  ( -81.20, 110.26)    0.69                24
 12/09/2022   13:36:43   (  81.20, -82.49) 12/09/2022   13:37:08  (  81.20, -82.35)    2.37                25
 12/09/2022   14:27:18   ( -81.20,  84.97) 12/09/2022   14:27:54  ( -81.20,  84.78)    3.22                36
 12/09/2022   15:18:02   (  81.20,-107.75) 12/09/2022   15:18:39  (  81.20,-107.83)    1.51                37
 12/09/2022   16:08:37   ( -81.20,  59.71) 12/09/2022   16:09:24  ( -81.20,  59.68)    0.50                47
 12/09/2022   16:59:22   (  81.20,-133.00) 12/09/2022   17:00:10  (  81.20,-132.93)    1.26                48
 12/09/2022   17:49:57   ( -81.20,  34.46) 12/09/2022   17:50:55  ( -81.20,  34.59)    2.24                58
 12/09/2022   18:40:42   (  81.20,-158.26) 12/09/2022   18:41:42  (  81.20,-158.41)    2.59                60
 12/09/2022   19:31:17   ( -81.19,   9.21) 12/09/2022   19:32:27  ( -81.20,   9.11)    1.67                70