Horizon mask: elevations and azimuths with mask values > 0 are removed
from plots.

EL
85: 000000000000000000000000000000000000000000000000000000000000000000000000
80: 000000000000000000000000000000000000000000000000000000000000000000000000
75: 000000000000000000000000000000000000000000000000000000000000000000000000
70: 000000000000000000000000000000000000000000000000000000000000000000000000
65: 000000000000000000000000000000000000000000000000000000000000000000000000
60: 000000000000000000000000000000000000000000000000000000000000000000000000
55: 000000000000000000000000000000000000000000000000000000000000000000000000
50: 000000000000000000000000000000000000000000000000000000000000000000000000
45: 000000000000000000000000000000000000000000000000000000000000000000000000
40: 000000000000000000000000000000000000000000000000000000110000000000000000
35: 000000000000000000000000000000000000000000000000111104752000000000000000
30: 000000000000000000000000000000000000000000001327662768774201000000000000
25: 000000000000000000000000001000000003352222437699998776886444422111111111
20: 332221100000000000000122211004000001498887818199919978118786776877665544
15: 543322100000000000002111001011000214799191199111191991977887988819887665
10: 443221100100000001111531011275532626911111111898851827668799977999877655
 5: 000000000000000000000000000000000000000000000000000000000000000000000000
 0: 000000000000000000000000000000000000000000000000000000000000000000000000
AZ:                     1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3
      1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
    0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0