There was some silent because of my participation in serious project. And now I try to compose an application for patent. It’s my favorite CPC (Cooperative Patent Classification) section G01S03/40 – “Radio direction-finding appartus using orientation of a single directivity characteristic to produce maximum or minimum signal”. In my opinion, it’s the most suitable section for mobile direction-finders. I found just single invention (US8456296, priority from 2009, by Radio System Corp), which looks similar to my design. The invention is named “Assisted direction finding apparatus”.
A tracking system based on this invention comprising transmitter carried by an object to be tracked and a directional receiver.
The invention comprises:
- a receiver with a signal strength detector;
- an electronic compass configured to determine and indicate a geographic direction;
- a display unit;
- a processor;
- a memory including computer program code.
The memory and the computer program code configured to, with the processor, cause the apparatus at least to:
- determine a direction and an angle of magnitude of a turn and a geographic direction of the apparatus in the horizontal plane;
- determine a signal strength received from the determined geographic direction;
- save the determined signal strength with the determined geographic direction;
- determine a maximum received signal strength from all received signal strengths; and
- show the determined geographic directions and a geographic direction of the maximum received signal strength on the display of the apparatus in their true directions.
The disadvantage of the invention is the low accuracy of determining the direction to the radiosignal source with use electronic compass. The compass is two or three axis magnetometer. Hovewer, the magnetic field intensity of the Earth depends on the geographical coordinates where it’s measured. Also directions to magnetic and geographic poles of the Earth are very different depending on geographical coordinates.
The proposed invention overcomes listed lacks. It further includes Attenuator, Sound, Haptic and Flash light outputs, Three-axis digital gyroscope and accelerometer-inclinometer, Wired and Wireless communication modules, Communication antenna, Satellite navigation signals receiver with Navigation antenna, and memory further includes Map-files and Magnetic inclination database file.
Blue sections – RF-part, green – basis system, yellow – user-interaction part, orange – spatial-orientation part, red – data-communication part.
Electronic compass allows to determine the initial azimuth relative to Earth’s magnetic poles. Satellite navigation signals receiver with Navigation antenna allow to determine the location coordinates. Magnetic inclination data allows to correct data from electronic compass and, hence, allows to determine the initial azimuth relative to Earth’s geographic poles. Sound, Haptic and Flash light outputs allow to improve user interaction level. Map-files allow to display an azimuth to a radio source on a map.