{
 "generated_utc": "2026-08-09T17:27:30Z",
 "gfs_cycle_utc": "2026-08-09T12:00:00Z",
 "model": {
  "source": "NCEP GFS 0.50 degree",
  "vertical_coordinate": "constant density (isopycnic)",
  "horizon_hours": 485.0,
  "output_interval_min": 30,
  "integration_step_s": 900,
  "wind_field_interval_h": 3
 },
 "staleness": {
  "fresh_seed_max_h": 24.0,
  "served_until_h": 336.0,
  "track_max_age_h": 72.0,
  "region_spread_deg": 60.0,
  "note": "A trajectory is served for 336 h after the last real fix and then the flight disappears. That matches the archive's own bridging limit: 23% of flights go quiet for over a week and are then heard again, so a shorter window drops balloons that are still flying. Past dead_reckoned flights the balloon has not been heard from since seed_time, so its present position is a prediction too -- the silent period is reconstructed from GFS analyses of weather that has already happened, which is why wind_source distinguishes analysis from forecast. Use display_as, not seed_age_h, to decide how to draw a flight: 'track' means the members still agree and a line is meaningful, 'region' means draw the member envelope instead because the nominal member is no better than any other."
 },
 "members": {
  "offsets_m": [
   -2000,
   -1500,
   -1000,
   -500,
   0,
   500,
   1000,
   1500,
   2000
  ],
  "nominal_offset_m": 0,
  "note": "Each member is seeded at the last observed altitude plus its offset and then conserves the density it started with. The ladder is a sensitivity fan, not a probability distribution: adjacent members diverge by roughly 1,200 km over seven days. levels_spanned reports how many GFS levels the fan actually straddles, usually 2 or 3."
 },
 "files": {
  "trajectories_csv_gz": "PBA_forecast_20260809_12Z.csv.gz",
  "trajectories_geojson_gz": "PBA_forecast_20260809_12Z.geojson.gz"
 },
 "counts": {
  "flights": 29,
  "members": 9,
  "rows": 138285
 },
 "flights": [
  {
   "callsign": "AG6NS-23",
   "flight_id": "AG6NS-23_2026-02-07",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 02:08:40",
   "seed_lat": -65.45834,
   "seed_lon": 152.41668,
   "seed_alt_m": 12570.0,
   "seed_age_h": 15.19,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:45:00",
    "lat": -44.78588,
    "lon": 78.07133,
    "alt_m": 12406.3
   },
   "member_spread_deg": {
    "lat": 19.12,
    "lon": 91.09
   },
   "member_spread_now_deg": {
    "lat": 7.18,
    "lon": 4.98
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "BSS53",
   "flight_id": "BSS53_2026-03-09",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 16:57:18",
   "seed_lat": 49.14583,
   "seed_lon": -42.70833,
   "seed_alt_m": 12710.0,
   "seed_age_h": 0.38,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 17:00:00",
    "lat": 55.98011,
    "lon": 90.16638,
    "alt_m": 12731.4
   },
   "member_spread_deg": {
    "lat": 19.98,
    "lon": 59.48
   },
   "member_spread_now_deg": {
    "lat": 0.17,
    "lon": 0.07
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "BSS54",
   "flight_id": "BSS54_2026-07-09",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 12:02:18",
   "seed_lat": 44.16667,
   "seed_lon": 71.33333,
   "seed_alt_m": 14180.0,
   "seed_age_h": 5.3,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 25.01635,
    "lon": 167.17867,
    "alt_m": 14605.7
   },
   "member_spread_deg": {
    "lat": 23.38,
    "lon": 322.44
   },
   "member_spread_now_deg": {
    "lat": 1.19,
    "lon": 2.52
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DG2GG-23",
   "flight_id": "DG2GG-23_2026-05-23",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 15:54:00",
   "seed_lat": 42.33333,
   "seed_lon": -73.0,
   "seed_alt_m": 12940.0,
   "seed_age_h": 1.43,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 15:30:00",
    "lat": 44.45059,
    "lon": 31.08048,
    "alt_m": 12737.3
   },
   "member_spread_deg": {
    "lat": 22.11,
    "lon": 128.97
   },
   "member_spread_now_deg": {
    "lat": 0.32,
    "lon": 0.34
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DG2GG-27",
   "flight_id": "DG2GG-27_2026-07-04",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 16:28:00",
   "seed_lat": 16.5,
   "seed_lon": -112.41667,
   "seed_alt_m": 13965.0,
   "seed_age_h": 0.87,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-16 16:00:00",
    "lat": 12.3321,
    "lon": -118.30353,
    "alt_m": 14021.1
   },
   "member_spread_deg": {
    "lat": 36.28,
    "lon": 62.3
   },
   "member_spread_now_deg": {
    "lat": 0.04,
    "lon": 0.26
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "DG2GG-29",
   "flight_id": "DG2GG-29_2026-07-28",
   "payload_type": "WSPR",
   "seed_time": "2026-08-04 04:57:00",
   "seed_lat": 46.91667,
   "seed_lon": 165.25,
   "seed_alt_m": 13380.0,
   "seed_age_h": 132.38,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 38.69025,
    "lon": -27.91423,
    "alt_m": 13671.4
   },
   "member_spread_deg": {
    "lat": 80.5,
    "lon": 272.05
   },
   "member_spread_now_deg": {
    "lat": 48.24,
    "lon": 319.55
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "DJ2DS-34",
   "flight_id": "DJ2DS-34_2026-04-22",
   "payload_type": "WSPR",
   "seed_time": "2026-07-28 14:41:00",
   "seed_lat": 30.70833,
   "seed_lon": -70.5,
   "seed_alt_m": 9190.0,
   "seed_age_h": 290.65,
   "float_reliable": false,
   "dead_reckoned": true,
   "levels_spanned": 4,
   "nominal_end": {
    "valid_time": "2026-08-16 11:45:00",
    "lat": 19.57578,
    "lon": 98.90046,
    "alt_m": 9043.1
   },
   "member_spread_deg": {
    "lat": 47.55,
    "lon": 296.4
   },
   "member_spread_now_deg": {
    "lat": 28.94,
    "lon": 151.06
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "DL0MZ-493",
   "flight_id": "DL0MZ-493_2026-07-25",
   "payload_type": "WSPR",
   "seed_time": "2026-07-29 07:36:01",
   "seed_lat": 64.20833,
   "seed_lon": 58.16667,
   "seed_alt_m": 12170.0,
   "seed_age_h": 273.73,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 50.66471,
    "lon": 60.34068,
    "alt_m": 11878.8
   },
   "member_spread_deg": {
    "lat": 37.16,
    "lon": 299.09
   },
   "member_spread_now_deg": {
    "lat": 45.27,
    "lon": 212.05
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "DL0MZ-493e",
   "flight_id": "DL0MZ-493e_2026-07-25",
   "payload_type": "WSPR",
   "seed_time": "2026-07-29 07:27:02",
   "seed_lat": 64.15625,
   "seed_lon": 58.08889,
   "seed_alt_m": 12170.0,
   "seed_age_h": 273.88,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 42.9404,
    "lon": -34.58577,
    "alt_m": 12791.6
   },
   "member_spread_deg": {
    "lat": 53.88,
    "lon": 202.35
   },
   "member_spread_now_deg": {
    "lat": 42.03,
    "lon": 79.79
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "DN3LEO-13",
   "flight_id": "DN3LEO-13_2026-04-12",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 16:53:00",
   "seed_lat": 59.22917,
   "seed_lon": -42.75,
   "seed_alt_m": 12340.0,
   "seed_age_h": 0.45,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-16 17:00:00",
    "lat": 79.76362,
    "lon": 89.04654,
    "alt_m": 12042.3
   },
   "member_spread_deg": {
    "lat": 27.53,
    "lon": 242.68
   },
   "member_spread_now_deg": {
    "lat": 0.12,
    "lon": 0.11
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "EI6BFW-18",
   "flight_id": "EI6BFW-18_2026-07-25",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 15:35:30",
   "seed_lat": 68.83333,
   "seed_lon": -117.75,
   "seed_alt_m": 12710.0,
   "seed_age_h": 1.74,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 15:00:00",
    "lat": 69.8464,
    "lon": -109.61904,
    "alt_m": 12235.6
   },
   "member_spread_deg": {
    "lat": 17.19,
    "lon": 49.31
   },
   "member_spread_now_deg": {
    "lat": 0.33,
    "lon": 0.28
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "K5NOT-11",
   "flight_id": "K5NOT-11_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 02:00:37",
   "seed_lat": 43.35411,
   "seed_lon": 172.04167,
   "seed_alt_m": 13390.0,
   "seed_age_h": 15.32,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 34.10789,
    "lon": -161.89349,
    "alt_m": 13574.0
   },
   "member_spread_deg": {
    "lat": 50.57,
    "lon": 302.88
   },
   "member_spread_now_deg": {
    "lat": 2.99,
    "lon": 1.43
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "K9YO-23",
   "flight_id": "K9YO-23_2026-07-13",
   "payload_type": "WSPR",
   "seed_time": "2026-07-27 06:25:49",
   "seed_lat": 52.5833,
   "seed_lon": 125.16663,
   "seed_alt_m": 12840.0,
   "seed_age_h": 322.9,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 39.42874,
    "lon": -117.64296,
    "alt_m": 13017.4
   },
   "member_spread_deg": {
    "lat": 59.19,
    "lon": 297.06
   },
   "member_spread_now_deg": {
    "lat": 66.82,
    "lon": 334.3
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "KC3LBR-449",
   "flight_id": "KC3LBR-449_2026-07-06",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 16:46:33",
   "seed_lat": 53.375,
   "seed_lon": -47.25,
   "seed_alt_m": 13440.0,
   "seed_age_h": 0.56,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 16:15:00",
    "lat": 63.26889,
    "lon": 79.70941,
    "alt_m": 13580.6
   },
   "member_spread_deg": {
    "lat": 23.32,
    "lon": 66.32
   },
   "member_spread_now_deg": {
    "lat": 0.12,
    "lon": 0.1
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KC3LBR-485",
   "flight_id": "KC3LBR-485_2026-03-19",
   "payload_type": "WSPR",
   "seed_time": "2026-07-28 09:08:18",
   "seed_lat": 50.14583,
   "seed_lon": 23.375,
   "seed_alt_m": 12850.0,
   "seed_age_h": 296.2,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:45:00",
    "lat": 62.11898,
    "lon": -14.0416,
    "alt_m": 12922.3
   },
   "member_spread_deg": {
    "lat": 49.6,
    "lon": 280.14
   },
   "member_spread_now_deg": {
    "lat": 29.58,
    "lon": 320.53
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "KC5TRB-1",
   "flight_id": "KC5TRB-1_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 16:55:43",
   "seed_lat": 63.66661,
   "seed_lon": -33.7083,
   "seed_alt_m": 12600.0,
   "seed_age_h": 0.41,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 17:00:00",
    "lat": 52.40017,
    "lon": 60.51155,
    "alt_m": 12382.3
   },
   "member_spread_deg": {
    "lat": 29.48,
    "lon": 295.92
   },
   "member_spread_now_deg": {
    "lat": 0.08,
    "lon": 0.11
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KD7FXO-1",
   "flight_id": "KD7FXO-1_2026-08-02",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 15:45:00",
   "seed_lat": 35.35417,
   "seed_lon": -29.95833,
   "seed_alt_m": 13170.0,
   "seed_age_h": 1.58,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 15:15:00",
    "lat": 49.0839,
    "lon": 82.11133,
    "alt_m": 12770.8
   },
   "member_spread_deg": {
    "lat": 13.5,
    "lon": 81.07
   },
   "member_spread_now_deg": {
    "lat": 0.34,
    "lon": 0.21
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KE8RES-8",
   "flight_id": "KE8RES-8_2026-06-20",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 16:41:00",
   "seed_lat": 58.66667,
   "seed_lon": -99.875,
   "seed_alt_m": 12100.0,
   "seed_age_h": 0.65,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-16 16:15:00",
    "lat": 61.09153,
    "lon": -71.47644,
    "alt_m": 11861.8
   },
   "member_spread_deg": {
    "lat": 18.8,
    "lon": 102.74
   },
   "member_spread_now_deg": {
    "lat": 0.07,
    "lon": 0.05
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KE9DAB-11",
   "flight_id": "KE9DAB-11_2026-07-29",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 11:33:30",
   "seed_lat": 50.6875,
   "seed_lon": 67.83333,
   "seed_alt_m": 12435.0,
   "seed_age_h": 5.78,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 43.97691,
    "lon": -179.01464,
    "alt_m": 12353.8
   },
   "member_spread_deg": {
    "lat": 27.85,
    "lon": 358.13
   },
   "member_spread_now_deg": {
    "lat": 0.45,
    "lon": 1.31
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "KI1TEN-1",
   "flight_id": "KI1TEN-1_2026-07-23",
   "payload_type": "WSPR",
   "seed_time": "2026-08-01 22:55:27",
   "seed_lat": 23.95828,
   "seed_lon": -104.12496,
   "seed_alt_m": 12380.0,
   "seed_age_h": 186.41,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 4.26022,
    "lon": -94.98623,
    "alt_m": 12361.0
   },
   "member_spread_deg": {
    "lat": 23.14,
    "lon": 94.53
   },
   "member_spread_now_deg": {
    "lat": 17.15,
    "lon": 21.61
   },
   "display_as": "region",
   "display_reason": "seed_age"
  },
  {
   "callsign": "KI6DS-11",
   "flight_id": "KI6DS-11_2026-02-03",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 16:55:45",
   "seed_lat": 59.43745,
   "seed_lon": -26.29165,
   "seed_alt_m": 13360.0,
   "seed_age_h": 0.41,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 17:00:00",
    "lat": 71.73937,
    "lon": 109.98821,
    "alt_m": 13394.8
   },
   "member_spread_deg": {
    "lat": 28.57,
    "lon": 121.15
   },
   "member_spread_now_deg": {
    "lat": 0.01,
    "lon": 0.44
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "SP2ROC-41",
   "flight_id": "SP2ROC-41_2026-01-25",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 05:33:00",
   "seed_lat": 61.375,
   "seed_lon": 170.29167,
   "seed_alt_m": 15860.0,
   "seed_age_h": 11.78,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 1,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 36.45317,
    "lon": -162.28047,
    "alt_m": 16411.2
   },
   "member_spread_deg": {
    "lat": 34.5,
    "lon": 335.7
   },
   "member_spread_now_deg": {
    "lat": 8.08,
    "lon": 358.76
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "SP6MPL-34",
   "flight_id": "SP6MPL-34_2025-12-03",
   "payload_type": "WSPR",
   "seed_time": "2026-07-31 18:52:00",
   "seed_lat": 74.5625,
   "seed_lon": -160.0,
   "seed_alt_m": 12890.0,
   "seed_age_h": 214.47,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:45:00",
    "lat": 54.36725,
    "lon": -92.49199,
    "alt_m": 13059.0
   },
   "member_spread_deg": {
    "lat": 33.36,
    "lon": 334.26
   },
   "member_spread_now_deg": {
    "lat": 22.17,
    "lon": 318.4
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "SP6MPL-9",
   "flight_id": "SP6MPL-9_2026-08-02",
   "payload_type": "APRS",
   "seed_time": "2026-08-04 04:05:45",
   "seed_lat": 45.52942,
   "seed_lon": 75.286,
   "seed_alt_m": 12836.0,
   "seed_age_h": 133.24,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 41.39365,
    "lon": 12.01367,
    "alt_m": 12987.5
   },
   "member_spread_deg": {
    "lat": 29.14,
    "lon": 188.61
   },
   "member_spread_now_deg": {
    "lat": 22.31,
    "lon": 346.43
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "VE3VRO-36",
   "flight_id": "VE3VRO-36_2026-07-30",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 11:31:00",
   "seed_lat": 48.25,
   "seed_lon": 79.70833,
   "seed_alt_m": 13270.0,
   "seed_age_h": 5.82,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 35.80339,
    "lon": -120.06464,
    "alt_m": 13459.5
   },
   "member_spread_deg": {
    "lat": 22.8,
    "lon": 337.47
   },
   "member_spread_now_deg": {
    "lat": 0.78,
    "lon": 5.21
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "W0RBO-12",
   "flight_id": "W0RBO-12_2026-05-02",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 12:10:23",
   "seed_lat": 42.68745,
   "seed_lon": 63.83336,
   "seed_alt_m": 13420.0,
   "seed_age_h": 5.16,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:45:00",
    "lat": 47.16075,
    "lon": -142.833,
    "alt_m": 13496.4
   },
   "member_spread_deg": {
    "lat": 17.4,
    "lon": 343.04
   },
   "member_spread_now_deg": {
    "lat": 0.49,
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   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "ZS6SRC-37",
   "flight_id": "ZS6SRC-37_2026-07-15",
   "payload_type": "WSPR",
   "seed_time": "2026-07-31 04:34:00",
   "seed_lat": -23.70833,
   "seed_lon": 149.29167,
   "seed_alt_m": 12380.0,
   "seed_age_h": 228.77,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 3,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": 3.85733,
    "lon": 39.09336,
    "alt_m": 12637.2
   },
   "member_spread_deg": {
    "lat": 50.05,
    "lon": 342.0
   },
   "member_spread_now_deg": {
    "lat": 22.81,
    "lon": 143.49
   },
   "display_as": "region",
   "display_reason": "member_spread"
  },
  {
   "callsign": "ZS6SRC-39",
   "flight_id": "ZS6SRC-39_2026-08-05",
   "payload_type": "WSPR",
   "seed_time": "2026-08-09 08:06:00",
   "seed_lat": -27.47917,
   "seed_lon": 86.95833,
   "seed_alt_m": 15460.0,
   "seed_age_h": 9.23,
   "float_reliable": true,
   "dead_reckoned": false,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:30:00",
    "lat": -7.04002,
    "lon": -179.36927,
    "alt_m": 15780.6
   },
   "member_spread_deg": {
    "lat": 21.37,
    "lon": 322.35
   },
   "member_spread_now_deg": {
    "lat": 0.28,
    "lon": 10.43
   },
   "display_as": "track",
   "display_reason": "fresh"
  },
  {
   "callsign": "ZS6SRC-84",
   "flight_id": "ZS6SRC-84_2026-07-12",
   "payload_type": "WSPR",
   "seed_time": "2026-07-27 15:20:00",
   "seed_lat": -7.75,
   "seed_lon": 8.375,
   "seed_alt_m": 13090.0,
   "seed_age_h": 314.0,
   "float_reliable": true,
   "dead_reckoned": true,
   "levels_spanned": 2,
   "nominal_end": {
    "valid_time": "2026-08-16 11:45:00",
    "lat": -0.07547,
    "lon": -43.25797,
    "alt_m": 13141.7
   },
   "member_spread_deg": {
    "lat": 42.66,
    "lon": 176.84
   },
   "member_spread_now_deg": {
    "lat": 31.53,
    "lon": 266.76
   },
   "display_as": "region",
   "display_reason": "member_spread"
  }
 ]
}