core/homeassistant/components/gpsd/icons.json

{
  "entity": {
    "sensor": {
      "mode": {
        "default": "mdi:crosshairs",
        "state": {
          "2d_fix": "mdi:crosshairs-gps",
          "3d_fix": "mdi:crosshairs-gps"
        }
      }
    }
  }
}