The need for 'sweet spots' and a grid of positions that the the telescope can point to is driven by the beamformer architecture. Each dipole can be delayed by an integer multiple of 435 picoseconds, where that integer ranges from 0-31, so the 'sweet spots' are the set of all of the positions on the sky where the geometric delays on every dipole on a tile are equal to an integer multiple of 435 picoseconds.

There's a table in the database that contains all of these positions. When we designed the system, we thought that some groups (like EOR) would only want to use a subset of all of the possible 'sweet spot' positions, so we allowed for multiple 'grids', each with a different name.

The set of every possible pointing with integer delays is called the 'sweet' grid:


  N  |    az    |   el    |                     delays
-----+----------+---------+------------------------------------------------
   0 |        0 |      90 | {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
   1 |        0 | 83.1912 | {3,3,3,3,2,2,2,2,1,1,1,1,0,0,0,0}
   2 |       90 | 83.1912 | {0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3}
   3 |      180 | 83.1912 | {0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3}
   4 |      270 | 83.1912 | {3,2,1,0,3,2,1,0,3,2,1,0,3,2,1,0}
   5 |       45 |  80.348 | {3,4,5,6,2,3,4,5,1,2,3,4,0,1,2,3}
   6 |      135 |  80.348 | {0,1,2,3,1,2,3,4,2,3,4,5,3,4,5,6}
   7 |      225 |  80.348 | {3,2,1,0,4,3,2,1,5,4,3,2,6,5,4,3}
   8 |      315 |  80.348 | {6,5,4,3,5,4,3,2,4,3,2,1,3,2,1,0}
   9 |        0 | 76.2838 | {6,6,6,6,4,4,4,4,2,2,2,2,0,0,0,0}
  10 |       90 | 76.2838 | {0,2,4,6,0,2,4,6,0,2,4,6,0,2,4,6}
  11 |      180 | 76.2838 | {0,0,0,0,2,2,2,2,4,4,4,4,6,6,6,6}
  12 |      270 | 76.2838 | {6,4,2,0,6,4,2,0,6,4,2,0,6,4,2,0}
  13 |  26.5651 | 74.6271 | {6,7,8,9,4,5,6,7,2,3,4,5,0,1,2,3}
  14 |  63.4349 | 74.6271 | {3,5,7,9,2,4,6,8,1,3,5,7,0,2,4,6}
  15 | 116.5651 | 74.6271 | {0,2,4,6,1,3,5,7,2,4,6,8,3,5,7,9}
  16 | 153.4349 | 74.6271 | {0,1,2,3,2,3,4,5,4,5,6,7,6,7,8,9}
  17 | 206.5651 | 74.6271 | {3,2,1,0,5,4,3,2,7,6,5,4,9,8,7,6}
  18 | 243.4349 | 74.6271 | {6,4,2,0,7,5,3,1,8,6,4,2,9,7,5,3}
  19 | 296.5651 | 74.6271 | {9,7,5,3,8,6,4,2,7,5,3,1,6,4,2,0}
  20 | 333.4349 | 74.6271 | {9,8,7,6,7,6,5,4,5,4,3,2,3,2,1,0}
  21 |       45 | 70.4075 | {6,8,10,12,4,6,8,10,2,4,6,8,0,2,4,6}
  22 |      135 | 70.4075 | {0,2,4,6,2,4,6,8,4,6,8,10,6,8,10,12}
  23 |      225 | 70.4075 | {6,4,2,0,8,6,4,2,10,8,6,4,12,10,8,6}
  24 |      315 | 70.4075 | {12,10,8,6,10,8,6,4,8,6,4,2,6,4,2,0}
  25 |        0 | 69.1655 | {9,9,9,9,6,6,6,6,3,3,3,3,0,0,0,0}
  26 |       90 | 69.1655 | {0,3,6,9,0,3,6,9,0,3,6,9,0,3,6,9}
  27 |      180 | 69.1655 | {0,0,0,0,3,3,3,3,6,6,6,6,9,9,9,9}
  28 |      270 | 69.1655 | {9,6,3,0,9,6,3,0,9,6,3,0,9,6,3,0}
  29 |  18.4349 | 67.9813 | {9,10,11,12,6,7,8,9,3,4,5,6,0,1,2,3}
  30 |  71.5651 | 67.9813 | {3,6,9,12,2,5,8,11,1,4,7,10,0,3,6,9}
  31 | 108.4349 | 67.9813 | {0,3,6,9,1,4,7,10,2,5,8,11,3,6,9,12}
  32 | 161.5651 | 67.9813 | {0,1,2,3,3,4,5,6,6,7,8,9,9,10,11,12}
  33 | 198.4349 | 67.9813 | {3,2,1,0,6,5,4,3,9,8,7,6,12,11,10,9}
  34 | 251.5651 | 67.9813 | {9,6,3,0,10,7,4,1,11,8,5,2,12,9,6,3}
  35 | 288.4349 | 67.9813 | {12,9,6,3,11,8,5,2,10,7,4,1,9,6,3,0}
  36 | 341.5651 | 67.9813 | {12,11,10,9,9,8,7,6,6,5,4,3,3,2,1,0}
  37 |  33.6901 | 64.6934 | {9,11,13,15,6,8,10,12,3,5,7,9,0,2,4,6}
  38 |  56.3099 | 64.6934 | {6,9,12,15,4,7,10,13,2,5,8,11,0,3,6,9}
  39 | 123.6901 | 64.6934 | {0,3,6,9,2,5,8,11,4,7,10,13,6,9,12,15}
  40 | 146.3099 | 64.6934 | {0,2,4,6,3,5,7,9,6,8,10,12,9,11,13,15}
  41 | 213.6901 | 64.6934 | {6,4,2,0,9,7,5,3,12,10,8,6,15,13,11,9}
  42 | 236.3099 | 64.6934 | {9,6,3,0,11,8,5,2,13,10,7,4,15,12,9,6}
  43 | 303.6901 | 64.6934 | {15,12,9,6,13,10,7,4,11,8,5,2,9,6,3,0}
  44 | 326.3099 | 64.6934 | {15,13,11,9,12,10,8,6,9,7,5,3,6,4,2,0}
  45 |        0 |  61.691 | {12,12,12,12,8,8,8,8,4,4,4,4,0,0,0,0}
  46 |       90 |  61.691 | {0,4,8,12,0,4,8,12,0,4,8,12,0,4,8,12}
  47 |      180 |  61.691 | {0,0,0,0,4,4,4,4,8,8,8,8,12,12,12,12}
  48 |      270 |  61.691 | {12,8,4,0,12,8,4,0,12,8,4,0,12,8,4,0}
  49 |  14.0362 | 60.7369 | {12,13,14,15,8,9,10,11,4,5,6,7,0,1,2,3}
  50 |  75.9638 | 60.7369 | {3,7,11,15,2,6,10,14,1,5,9,13,0,4,8,12}
  51 | 104.0362 | 60.7369 | {0,4,8,12,1,5,9,13,2,6,10,14,3,7,11,15}
  52 | 165.9638 | 60.7369 | {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}
  53 | 194.0362 | 60.7369 | {3,2,1,0,7,6,5,4,11,10,9,8,15,14,13,12}
  54 | 255.9638 | 60.7369 | {12,8,4,0,13,9,5,1,14,10,6,2,15,11,7,3}
  55 | 284.0362 | 60.7369 | {15,11,7,3,14,10,6,2,13,9,5,1,12,8,4,0}
  56 | 345.9638 | 60.7369 | {15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0}
  57 |       45 | 59.8018 | {9,12,15,18,6,9,12,15,3,6,9,12,0,3,6,9}
  58 |      135 | 59.8018 | {0,3,6,9,3,6,9,12,6,9,12,15,9,12,15,18}
  59 |      225 | 59.8018 | {9,6,3,0,12,9,6,3,15,12,9,6,18,15,12,9}
  60 |      315 | 59.8018 | {18,15,12,9,15,12,9,6,12,9,6,3,9,6,3,0}
  61 |  26.5651 |  57.981 | {12,14,16,18,8,10,12,14,4,6,8,10,0,2,4,6}
  62 |  63.4349 |  57.981 | {6,10,14,18,4,8,12,16,2,6,10,14,0,4,8,12}
  63 | 116.5651 |  57.981 | {0,4,8,12,2,6,10,14,4,8,12,16,6,10,14,18}
  64 | 153.4349 |  57.981 | {0,2,4,6,4,6,8,10,8,10,12,14,12,14,16,18}
  65 | 206.5651 |  57.981 | {6,4,2,0,10,8,6,4,14,12,10,8,18,16,14,12}
  66 | 243.4349 |  57.981 | {12,8,4,0,14,10,6,2,16,12,8,4,18,14,10,6}
  67 | 296.5651 |  57.981 | {18,14,10,6,16,12,8,4,14,10,6,2,12,8,4,0}
  68 | 333.4349 |  57.981 | {18,16,14,12,14,12,10,8,10,8,6,4,6,4,2,0}
  69 |        0 | 53.6453 | {15,15,15,15,10,10,10,10,5,5,5,5,0,0,0,0}
  70 |  36.8699 | 53.6453 | {12,15,18,21,8,11,14,17,4,7,10,13,0,3,6,9}
  71 |  53.1301 | 53.6453 | {9,13,17,21,6,10,14,18,3,7,11,15,0,4,8,12}
  72 |       90 | 53.6453 | {0,5,10,15,0,5,10,15,0,5,10,15,0,5,10,15}
  73 | 126.8699 | 53.6453 | {0,4,8,12,3,7,11,15,6,10,14,18,9,13,17,21}
  74 | 143.1301 | 53.6453 | {0,3,6,9,4,7,10,13,8,11,14,17,12,15,18,21}
  75 |      180 | 53.6453 | {0,0,0,0,5,5,5,5,10,10,10,10,15,15,15,15}
  76 | 216.8699 | 53.6453 | {9,6,3,0,13,10,7,4,17,14,11,8,21,18,15,12}
  77 | 233.1301 | 53.6453 | {12,8,4,0,15,11,7,3,18,14,10,6,21,17,13,9}
  78 |      270 | 53.6453 | {15,10,5,0,15,10,5,0,15,10,5,0,15,10,5,0}
  79 | 306.8699 | 53.6453 | {21,17,13,9,18,14,10,6,15,11,7,3,12,8,4,0}
  80 | 323.1301 | 53.6453 | {21,18,15,12,17,14,11,8,13,10,7,4,9,6,3,0}
  81 |  11.3099 | 52.8056 | {15,16,17,18,10,11,12,13,5,6,7,8,0,1,2,3}
  82 |  78.6901 | 52.8056 | {3,8,13,18,2,7,12,17,1,6,11,16,0,5,10,15}
  83 | 101.3099 | 52.8056 | {0,5,10,15,1,6,11,16,2,7,12,17,3,8,13,18}
  84 | 168.6901 | 52.8056 | {0,1,2,3,5,6,7,8,10,11,12,13,15,16,17,18}
  85 | 191.3099 | 52.8056 | {3,2,1,0,8,7,6,5,13,12,11,10,18,17,16,15}
  86 | 258.6901 | 52.8056 | {15,10,5,0,16,11,6,1,17,12,7,2,18,13,8,3}
  87 | 281.3099 | 52.8056 | {18,13,8,3,17,12,7,2,16,11,6,1,15,10,5,0}
  88 | 348.6901 | 52.8056 | {18,17,16,15,13,12,11,10,8,7,6,5,3,2,1,0}
  89 |  21.8014 | 50.3239 | {15,17,19,21,10,12,14,16,5,7,9,11,0,2,4,6}
  90 |  68.1986 | 50.3239 | {6,11,16,21,4,9,14,19,2,7,12,17,0,5,10,15}
  91 | 111.8014 | 50.3239 | {0,5,10,15,2,7,12,17,4,9,14,19,6,11,16,21}
  92 | 158.1986 | 50.3239 | {0,2,4,6,5,7,9,11,10,12,14,16,15,17,19,21}
  93 | 201.8014 | 50.3239 | {6,4,2,0,11,9,7,5,16,14,12,10,21,19,17,15}
  94 | 248.1986 | 50.3239 | {15,10,5,0,17,12,7,2,19,14,9,4,21,16,11,6}
  95 | 291.8014 | 50.3239 | {21,16,11,6,19,14,9,4,17,12,7,2,15,10,5,0}
  96 | 338.1986 | 50.3239 | {21,19,17,15,16,14,12,10,11,9,7,5,6,4,2,0}
  97 |       45 | 47.8822 | {12,16,20,24,8,12,16,20,4,8,12,16,0,4,8,12}
  98 |      135 | 47.8822 | {0,4,8,12,4,8,12,16,8,12,16,20,12,16,20,24}
  99 |      225 | 47.8822 | {12,8,4,0,16,12,8,4,20,16,12,8,24,20,16,12}
 100 |      315 | 47.8822 | {24,20,16,12,20,16,12,8,16,12,8,4,12,8,4,0}
 101 |  30.9638 | 46.2671 | {15,18,21,24,10,13,16,19,5,8,11,14,0,3,6,9}
 102 |  59.0362 | 46.2671 | {9,14,19,24,6,11,16,21,3,8,13,18,0,5,10,15}
 103 | 120.9638 | 46.2671 | {0,5,10,15,3,8,13,18,6,11,16,21,9,14,19,24}
 104 | 149.0362 | 46.2671 | {0,3,6,9,5,8,11,14,10,13,16,19,15,18,21,24}
 105 | 210.9638 | 46.2671 | {9,6,3,0,14,11,8,5,19,16,13,10,24,21,18,15}
 106 | 239.0362 | 46.2671 | {15,10,5,0,18,13,8,3,21,16,11,6,24,19,14,9}
 107 | 300.9638 | 46.2671 | {24,19,14,9,21,16,11,6,18,13,8,3,15,10,5,0}
 108 | 329.0362 | 46.2671 | {24,21,18,15,19,16,13,10,14,11,8,5,9,6,3,0}
 109 |        0 |  44.656 | {18,18,18,18,12,12,12,12,6,6,6,6,0,0,0,0}
 110 |       90 |  44.656 | {0,6,12,18,0,6,12,18,0,6,12,18,0,6,12,18}
 111 |      180 |  44.656 | {0,0,0,0,6,6,6,6,12,12,12,12,18,18,18,18}
 112 |      270 |  44.656 | {18,12,6,0,18,12,6,0,18,12,6,0,18,12,6,0}
 113 |   9.4623 | 43.8504 | {18,19,20,21,12,13,14,15,6,7,8,9,0,1,2,3}
 114 |  80.5377 | 43.8504 | {3,9,15,21,2,8,14,20,1,7,13,19,0,6,12,18}
 115 |  99.4623 | 43.8504 | {0,6,12,18,1,7,13,19,2,8,14,20,3,9,15,21}
 116 | 170.5377 | 43.8504 | {0,1,2,3,6,7,8,9,12,13,14,15,18,19,20,21}
 117 | 189.4623 | 43.8504 | {3,2,1,0,9,8,7,6,15,14,13,12,21,20,19,18}
 118 | 260.5377 | 43.8504 | {18,12,6,0,19,13,7,1,20,14,8,2,21,15,9,3}
 119 | 279.4623 | 43.8504 | {21,15,9,3,20,14,8,2,19,13,7,1,18,12,6,0}
 120 | 350.5377 | 43.8504 | {21,20,19,18,15,14,13,12,9,8,7,6,3,2,1,0}
 121 |  18.4349 | 41.4255 | {18,20,22,24,12,14,16,18,6,8,10,12,0,2,4,6}
 122 |  71.5651 | 41.4255 | {6,12,18,24,4,10,16,22,2,8,14,20,0,6,12,18}
 123 | 108.4349 | 41.4255 | {0,6,12,18,2,8,14,20,4,10,16,22,6,12,18,24}
 124 | 161.5651 | 41.4255 | {0,2,4,6,6,8,10,12,12,14,16,18,18,20,22,24}
 125 | 198.4349 | 41.4255 | {6,4,2,0,12,10,8,6,18,16,14,12,24,22,20,18}
 126 | 251.5651 | 41.4255 | {18,12,6,0,20,14,8,2,22,16,10,4,24,18,12,6}
 127 | 288.4349 | 41.4255 | {24,18,12,6,22,16,10,4,20,14,8,2,18,12,6,0}
 128 | 341.5651 | 41.4255 | {24,22,20,18,18,16,14,12,12,10,8,6,6,4,2,0}
 129 |  38.6598 | 40.6123 | {15,19,23,27,10,14,18,22,5,9,13,17,0,4,8,12}
 130 |  51.3402 | 40.6123 | {12,17,22,27,8,13,18,23,4,9,14,19,0,5,10,15}
 131 | 128.6598 | 40.6123 | {0,5,10,15,4,9,14,19,8,13,18,23,12,17,22,27}
 132 | 141.3402 | 40.6123 | {0,4,8,12,5,9,13,17,10,14,18,22,15,19,23,27}
 133 | 218.6598 | 40.6123 | {12,8,4,0,17,13,9,5,22,18,14,10,27,23,19,15}
 134 | 231.3402 | 40.6123 | {15,10,5,0,19,14,9,4,23,18,13,8,27,22,17,12}
 135 | 308.6598 | 40.6123 | {27,22,17,12,23,18,13,8,19,14,9,4,15,10,5,0}
 136 | 321.3402 | 40.6123 | {27,23,19,15,22,18,14,10,17,13,9,5,12,8,4,0}
 137 |  26.5651 | 37.3163 | {18,21,24,27,12,15,18,21,6,9,12,15,0,3,6,9}
 138 |  63.4349 | 37.3163 | {9,15,21,27,6,12,18,24,3,9,15,21,0,6,12,18}
 139 | 116.5651 | 37.3163 | {0,6,12,18,3,9,15,21,6,12,18,24,9,15,21,27}
 140 | 153.4349 | 37.3163 | {0,3,6,9,6,9,12,15,12,15,18,21,18,21,24,27}
 141 | 206.5651 | 37.3163 | {9,6,3,0,15,12,9,6,21,18,15,12,27,24,21,18}
 142 | 243.4349 | 37.3163 | {18,12,6,0,21,15,9,3,24,18,12,6,27,21,15,9}
 143 | 296.5651 | 37.3163 | {27,21,15,9,24,18,12,6,21,15,9,3,18,12,6,0}
 144 | 333.4349 | 37.3163 | {27,24,21,18,21,18,15,12,15,12,9,6,9,6,3,0}
 145 |        0 |  33.912 | {21,21,21,21,14,14,14,14,7,7,7,7,0,0,0,0}
 146 |       90 |  33.912 | {0,7,14,21,0,7,14,21,0,7,14,21,0,7,14,21}
 147 |      180 |  33.912 | {0,0,0,0,7,7,7,7,14,14,14,14,21,21,21,21}
 148 |      270 |  33.912 | {21,14,7,0,21,14,7,0,21,14,7,0,21,14,7,0}
 149 |   8.1301 | 33.0368 | {21,22,23,24,14,15,16,17,7,8,9,10,0,1,2,3}
 150 |       45 | 33.0368 | {15,20,25,30,10,15,20,25,5,10,15,20,0,5,10,15}
 151 |  81.8699 | 33.0368 | {3,10,17,24,2,9,16,23,1,8,15,22,0,7,14,21}
 152 |  98.1301 | 33.0368 | {0,7,14,21,1,8,15,22,2,9,16,23,3,10,17,24}
 153 |      135 | 33.0368 | {0,5,10,15,5,10,15,20,10,15,20,25,15,20,25,30}
 154 | 171.8699 | 33.0368 | {0,1,2,3,7,8,9,10,14,15,16,17,21,22,23,24}
 155 | 188.1301 | 33.0368 | {3,2,1,0,10,9,8,7,17,16,15,14,24,23,22,21}
 156 |      225 | 33.0368 | {15,10,5,0,20,15,10,5,25,20,15,10,30,25,20,15}
 157 | 261.8699 | 33.0368 | {21,14,7,0,22,15,8,1,23,16,9,2,24,17,10,3}
 158 | 278.1301 | 33.0368 | {24,17,10,3,23,16,9,2,22,15,8,1,21,14,7,0}
 159 |      315 | 33.0368 | {30,25,20,15,25,20,15,10,20,15,10,5,15,10,5,0}
 160 | 351.8699 | 33.0368 | {24,23,22,21,17,16,15,14,10,9,8,7,3,2,1,0}
 161 |  33.6901 | 31.2488 | {18,22,26,30,12,16,20,24,6,10,14,18,0,4,8,12}
 162 |  56.3099 | 31.2488 | {12,18,24,30,8,14,20,26,4,10,16,22,0,6,12,18}
 163 | 123.6901 | 31.2488 | {0,6,12,18,4,10,16,22,8,14,20,26,12,18,24,30}
 164 | 146.3099 | 31.2488 | {0,4,8,12,6,10,14,18,12,16,20,24,18,22,26,30}
 165 | 213.6901 | 31.2488 | {12,8,4,0,18,14,10,6,24,20,16,12,30,26,22,18}
 166 | 236.3099 | 31.2488 | {18,12,6,0,22,16,10,4,26,20,14,8,30,24,18,12}
 167 | 303.6901 | 31.2488 | {30,24,18,12,26,20,14,8,22,16,10,4,18,12,6,0}
 168 | 326.3099 | 31.2488 | {30,26,22,18,24,20,16,12,18,14,10,6,12,8,4,0}
 169 |  15.9454 | 30.3331 | {21,23,25,27,14,16,18,20,7,9,11,13,0,2,4,6}
 170 |  74.0546 | 30.3331 | {6,13,20,27,4,11,18,25,2,9,16,23,0,7,14,21}
 171 | 105.9454 | 30.3331 | {0,7,14,21,2,9,16,23,4,11,18,25,6,13,20,27}
 172 | 164.0546 | 30.3331 | {0,2,4,6,7,9,11,13,14,16,18,20,21,23,25,27}
 173 | 195.9454 | 30.3331 | {6,4,2,0,13,11,9,7,20,18,16,14,27,25,23,21}
 174 | 254.0546 | 30.3331 | {21,14,7,0,23,16,9,2,25,18,11,4,27,20,13,6}
 175 | 285.9454 | 30.3331 | {27,20,13,6,25,18,11,4,23,16,9,2,21,14,7,0}
 176 | 344.0546 | 30.3331 | {27,25,23,21,20,18,16,14,13,11,9,7,6,4,2,0}
 177 |  23.1986 | 25.4582 | {21,24,27,30,14,17,20,23,7,10,13,16,0,3,6,9}
 178 |  66.8014 | 25.4582 | {9,16,23,30,6,13,20,27,3,10,17,24,0,7,14,21}
 179 | 113.1986 | 25.4582 | {0,7,14,21,3,10,17,24,6,13,20,27,9,16,23,30}
 180 | 156.8014 | 25.4582 | {0,3,6,9,7,10,13,16,14,17,20,23,21,24,27,30}
 181 | 203.1986 | 25.4582 | {9,6,3,0,16,13,10,7,23,20,17,14,30,27,24,21}
 182 | 246.8014 | 25.4582 | {21,14,7,0,24,17,10,3,27,20,13,6,30,23,16,9}
 183 | 293.1986 | 25.4582 | {30,23,16,9,27,20,13,6,24,17,10,3,21,14,7,0}
 184 | 336.8014 | 25.4582 | {30,27,24,21,23,20,17,14,16,13,10,7,9,6,3,0}
 185 |        0 | 18.4768 | {24,24,24,24,16,16,16,16,8,8,8,8,0,0,0,0}
 186 |       90 | 18.4768 | {0,8,16,24,0,8,16,24,0,8,16,24,0,8,16,24}
 187 |      180 | 18.4768 | {0,0,0,0,8,8,8,8,16,16,16,16,24,24,24,24}
 188 |      270 | 18.4768 | {24,16,8,0,24,16,8,0,24,16,8,0,24,16,8,0}
 189 |    7.125 | 17.0922 | {24,25,26,27,16,17,18,19,8,9,10,11,0,1,2,3}
 190 |   82.875 | 17.0922 | {3,11,19,27,2,10,18,26,1,9,17,25,0,8,16,24}
 191 |   97.125 | 17.0922 | {0,8,16,24,1,9,17,25,2,10,18,26,3,11,19,27}
 192 |  172.875 | 17.0922 | {0,1,2,3,8,9,10,11,16,17,18,19,24,25,26,27}
 193 |  187.125 | 17.0922 | {3,2,1,0,11,10,9,8,19,18,17,16,27,26,25,24}
 194 |  262.875 | 17.0922 | {24,16,8,0,25,17,9,1,26,18,10,2,27,19,11,3}
 195 |  277.125 | 17.0922 | {27,19,11,3,26,18,10,2,25,17,9,1,24,16,8,0}
 196 |  352.875 | 17.0922 | {27,26,25,24,19,18,17,16,11,10,9,8,3,2,1,0}


When an observation is scheduled, it finds the closest 'sweet' grid position (by default) to the supplied RA/Dec, Az/El or source position, and uses those delays for the beamformers.

The 'EOR1' grid only has 11 positions, and was used during the observations for the first few EoR observing seasons:


 n  |    az    |   el    |                  delays
----+----------+---------+-------------------------------------------
  0 |        0 |      90 | {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
  1 |       90 | 83.1912 | {0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3}
  2 |      270 | 83.1912 | {3,2,1,0,3,2,1,0,3,2,1,0,3,2,1,0}
  3 |       90 | 76.2838 | {0,2,4,6,0,2,4,6,0,2,4,6,0,2,4,6}
  4 |      270 | 76.2838 | {6,4,2,0,6,4,2,0,6,4,2,0,6,4,2,0}
  5 |       90 | 69.1655 | {0,3,6,9,0,3,6,9,0,3,6,9,0,3,6,9}
  6 |      270 | 69.1655 | {9,6,3,0,9,6,3,0,9,6,3,0,9,6,3,0}
  7 | 104.0362 | 60.7369 | {0,4,8,12,1,5,9,13,2,6,10,14,3,7,11,15}
  8 | 255.9638 | 60.7369 | {12,8,4,0,13,9,5,1,14,10,6,2,15,11,7,3}
  9 | 101.3099 | 52.8056 | {0,5,10,15,1,6,11,16,2,7,12,17,3,8,13,18}
 10 | 281.3099 | 52.8056 | {18,13,8,3,17,12,7,2,16,11,6,1,15,10,5,0}


You can see that EOR1 grid point 0 has the same delays (and az/el) as 'sweet' grid point 0, but EOR1 grid point 1 matches 'sweet' grid point 2, EOR grid point 2 matches 'sweet' grid point 4, etc.

The full mapping between the two is here:


EOR1  sweet      delays
0     0    [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
1     2    [0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3]
2     4    [3,2,1,0,3,2,1,0,3,2,1,0,3,2,1,0]
3    10    [0,2,4,6,0,2,4,6,0,2,4,6,0,2,4,6]
4    12    [6,4,2,0,6,4,2,0,6,4,2,0,6,4,2,0]
5    26    [0,3,6,9,0,3,6,9,0,3,6,9,0,3,6,9]
6    28    [9,6,3,0,9,6,3,0,9,6,3,0,9,6,3,0]
7    51    [0,4,8,12,1,5,9,13,2,6,10,14,3,7,11,15]
8    54    [12,8,4,0,13,9,5,1,14,10,6,2,15,11,7,3]
9    83    [0,5,10,15,1,6,11,16,2,7,12,17,3,8,13,18]
10   87    [18,13,8,3,17,12,7,2,16,11,6,1,15,10,5,0]


For the first few years of MWA observations, EOR observations were scheduled with the 'EOR1' grid point numbers, but then everyone started using 'sweet' gridpoint numbers for all observations. The only important thing is what actual delays are sent to the beamformers, not what the grid point number name is.