Artifact in pass schedule listing

[bjorgan]

Passes listed in "Predict passes" are sometimes listed with negative elevations, or include times that are obviously not a part of the pass.

Reproduction:

ISS (ZARYA)
1 25544U 98067A   18090.58626157  .00001630  00000-0  31800-4 0  9994
2 25544  51.6406  45.5717 0001685 278.7810  65.9688 15.54173033106445

Station latitude: 63.511200
Station longitude: 10.020900

Start flyby at 2018-03-31 17:24 UTC: Option 'P' yields

      Fri 06Apr18 15:27:57   0  203    87    44    359     2322   10738 *
      Fri 06Apr18 15:29:07   3  192    90    46      4     2008   10738 *
      Fri 06Apr18 15:30:17   5  179    93    48     10     1777   10738 *
      Fri 06Apr18 15:31:27   7  162    96    49     16     1666   10738 *
      Fri 06Apr18 15:32:36   6  144    99    50     23     1700   10738 *
      Fri 06Apr18 15:33:46   4  129   103    51     30     1869   10738 *
      Fri 06Apr18 15:34:56   1  116   106    51     37     2143   10738 *
      Sat 07Apr18 14:43:18   0  111   102    51     41     2329   10753 *

This case also seems to be slightly inconsistent, changing from time to time 'P' is selected, could also be indicative of problems with AOS/LOS finding.