Simultaneous Nadir Overpasses (SNOs) between GOES-15 and NPP
TLE Epoch: 2017 7 20.  Predictions up to the next  14.0 days:

     Date     Time(GOES-15)   GOES-15 Lat/Lon  NPP Lat/Lon    Distance(km)  Time Diff(sec)
 07/21/2017   10:24:13   (  -0.19,-135.07) (  -0.18,-135.11)    4.80                80
 07/23/2017   22:27:28   (   0.21,-135.03) (   0.04,-135.90)   98.77                80
 07/24/2017   22:11:24   (   0.20,-135.00) (   1.01,-131.36)  414.11                80
 07/26/2017   10:30:33   (  -0.22,-134.91) (   0.16,-136.64)  197.20                80
 07/27/2017   10:14:29   (  -0.21,-134.87) (  -0.81,-132.10)  315.24                80
 07/28/2017   22:33:47   (   0.23,-134.85) (  -0.35,-137.41)  292.35                80
 07/29/2017   22:17:43   (   0.22,-134.82) (   0.67,-132.89)  220.16                80
 07/31/2017   10:36:53   (  -0.25,-134.73) (   0.49,-138.17)  391.25                80
 08/01/2017   10:20:48   (  -0.24,-134.68) (  -0.47,-133.63)  120.51                80
 08/02/2017   22:40:07   (   0.26,-134.65) (  -0.68,-138.94)  488.82                80