http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-3936828-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_9dc38948bd77222db9e6598ec4b60d67 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G01S1-30 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G01S1-02 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01S1-30 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01S19-23 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01S1-02 |
| filingDate | 1973-11-19-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| grantDate | 1976-02-03-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_5270a23835a2e9df769a34303b08a910 http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_2a8063499e9d737297095f6bd0d83594 |
| publicationDate | 1976-02-03-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | US-3936828-A |
| titleOfInvention | VLF navigation system |
| abstract | A VLF navigation system suitable for highly accurate worldwide aircraft navigation utilizing existing VLF transmitting stations on a "dead reckoning" basis with initial and intermediate fixes. The system is enabled to utilize all existing VLF transmitting stations regardless of station frequency by novel receiver phase-locked loop means which normalizes all station frequencies to phase coherent independent data signals of a common working frequency. In one form of the invention, utilizing hyperbolic coordinates, both RF stations of each station pair utilized for computation are such VLF transmitting stations; while in another form of the invention, utilizing Rho-Rho coordinates, one RF station of each station pair is an on-board frequency standard normalized to the common working frequency, and the other station of each pair is one of the VLF transmitting stations. n Computer means, which may be part of the "on-board" equipment, selects station pairs for optimum station geometry and range, and by comparing the phase differences between the phase coherent data signals for respective station pairs, determines a Δ time and hence a Δ position in suitable coordinates from the initial or intermediate calibration point. Novel multiplexing and counting means, and logic circuitry associated therewith, enable a single counting means to be rapidly sequentially employed by the computer to make the time difference comparison for a series of station pairs. n The system is extremely accurate for a number of reasons, including but not limited to the inherent frequency stability of VLF transmitting stations (which are generally atomic clock controlled); the inherent minimal distortion of VLF electromagnetic signals over very long ranges; the fact that errors are not cumulative in the system; and a station pair averaging capability which decreases random errors and permits rejection of the defective signals. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4496951-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2008103646-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/WO-2007051712-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2008252511-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-5457455-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6169902-B1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/FR-2516249-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6282417-B1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2009066560-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EP-0082750-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-7898467-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/FR-3088443-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EP-3657210-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-11385073-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6876926-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-8209115-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EP-0079280-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-7652621-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-5742679-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/FR-2518758-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/FR-2893144-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4038529-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-2004064252-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4651282-A |
| priorityDate | 1972-12-22-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 52.