Method to Extract Weather Information from an After-Market GPS Apparatus
Original Publication Date: 2009-Jan-15
Included in the Prior Art Database: 2009-Jan-15
The invention described herein is a method to enable users of 2-way GPS navigation to provide weather-related information to a service for the aggregation and consumption by other subscribers of the service without the aid of specialized weather-detecting equipment. Providers of traffic and weather information have already leveraged the capability of 2-way GPS devices to enable the transmission of traffic information, ie rate and direction of travel as well as time and place, to so-called real time traffic information to subscribers of the service. This invention proposes to leverage the detected state of operation of a vehicle's windshield wipers to provide weather information as an augmentation to the traffic information.
Method to Extract Weather Information from an After -Market GPS Apparatus
Electricity being a flow of electrons in a closed loop is disrupted whenever a device attached to the loop operates. This is normal and expected behavior as the length of the loop is extended or reduced by the switch that initiates and/or terminates the device's operation. Furthermore, electrically-driven motors by their nature create an electromagnetic field (EMF) whenever they are operated. This EMF causes electromagnetic interference (EMI or so-called noise) on the electric line. So much so that it is well-known art that a field of study and market segments exist for filters designed to suppressing EMI caused by EMF. Consider the closed loop electrical circuit that is formed inside an automobile. Because of its confined space EMI is easily detected through the amplified reception of Amplitude Modulation radio signals. Anyone that has heard their engine come through their radio will instantly recognize the condition and the need for appropriate and/or supplemental isolation or filtering. Likewise, the operation of windshield wipers causes EMI --albeit at a smaller magnitude-- that is detectable with sufficiently sophisticated meters.
Weather forecasting is a well known field of study based on the keen observation of several weather phenomena, the measurement thereof and the application of mathematical models to the measured phenomena. The plurality of the applied mathematical models yield a plurality of metrics that when aggregated are combined into a single forecast. These forecasts usually are coupled with a measure of the degree of confidence, such as 30% chance of rain.
The Global Positioning System (GPS) is the only fully functional Global Navigation Satellite System (GNSS). Utilizing a constellation of at least 24 Medium Earth Orbit satellites that transmit precise microwave signals, the system enables a GPS receiver to determine its location, speed, direction, and time. Developed by the United States Department of Defense, GPS is officially named NAVSTAR GPS. A typical GPS receiver calculates its position using the signals from three or more GPS satellites. Four satellites are needed since the process needs a very accurate local time, more accurate than any normal clock can provide, so the receiver internally solves for time as well as position. In other words, the receiver uses four measurements to solve for 4 variables - x, y, z, and t. These values are then turned into more user-friendly forms, such as latitude/longitude or location on a map, then displayed to the user. Each GPS satellite has an atomic clock, and continually transmits messages containing the current time at the start of the message, parameters to calculate the location of the satellite (the ephemeris), and the general system health (the almanac). The signals travel at a known speed - the speed of l...