{
  "patent_number": "US 6816710",
  "country": "US",
  "title": "How GPS Receivers See Weak Signals by Combining Data",
  "original_title": "Method and apparatus for signal processing in a satellite positioning system",
  "summary": "A method for improving GPS sensitivity by mathematically combining multiple, weak signal samples to extract navigation data that would otherwise be lost in noise.",
  "what_it_does": "This patent describes a way to make GPS receivers work in difficult environments, such as indoors or in urban canyons where satellite signals are very faint. The receiver captures multiple versions of the same signal over time. Because these signals contain repetitive data, the receiver can mathematically combine or 'sum' these samples. To ensure the final result is as clear as possible, the system weights each sample based on its signal-to-noise ratio, effectively giving more importance to the cleaner data. This process allows the device to pull usable navigation information out of what would otherwise appear as random background noise.",
  "what_it_does_not_cover": [
    "Does not cover GPS signal processing that relies solely on a single, instantaneous signal capture.",
    "Does not cover methods that do not involve weighting the samples based on the signal-to-noise ratio.",
    "Does not cover hardware-agnostic software that does not interact with satellite positioning system signals.",
    "Does not cover non-repetitive data streams that lack common information between signal samples."
  ],
  "filed": "1998-05-06",
  "granted": "2004-11-09",
  "expires": null,
  "status": "active",
  "holder": "SnapTrack Inc",
  "holder_url": "https://patentbrief.org/company/snaptrack-inc",
  "inventors": [
    {
      "name": "Norman F. Krasner",
      "url": "https://patentbrief.org/inventor/norman-f-krasner"
    }
  ],
  "times_cited": 76,
  "tags": [
    "consumer_electronics",
    "telecommunications",
    "semiconductors"
  ],
  "abstract": "A method and apparatus for processing satellite positioning system (SPS) signals which are weak in level. In one embodiment, a SPS receiver receives at least two signal samples representing, at least in part, common information, wherein the two signal samples are associated with one or more satellite messages. By combining the two signal samples, navigational information (e.g., time, position, velocity, etc.) may be determined based on the combination of the two signal samples. According to another embodiment, the two signal samples are differentially demodulated and summed together to form the combination.",
  "url": "https://patentbrief.org/patent/us/6816710/reusable-launch-vehicle-falcon-9-booster-landing",
  "markdown_url": "https://patentbrief.org/patent/us/6816710/reusable-launch-vehicle-falcon-9-booster-landing/md",
  "google_patents_url": "https://patents.google.com/patent/US6816710",
  "relatedPatents": []
}