초록 ▼

An accurate ranging system for position determination of a mobile unit using trilateralization. A pair of active reflectors return signals transmitted by the mobile unit in phase at the reflectors, after compensating for interval circuit delay. The mobile unit compares the phases and determines mutu

An accurate ranging system for position determination of a mobile unit using trilateralization. A pair of active reflectors return signals transmitted by the mobile unit in phase at the reflectors, after compensating for interval circuit delay. The mobile unit compares the phases and determines mutual distances and thus its position. The invention includes a two frequency technique for compensating for inaccuracies introduced at distances in excess of one wavelength and for inaccuracies observed at a large multiple of wavelengths, and also includes means for dynamically compensating for drift.

대표청구항 ▼

A ranging system comprising: (a) first means for transmitting a first continuous wave (CW) signal for a predetermined period of time, and for generating a second CW signal for a predetermined period of time at a frequency which is a very large fraction of the first CW signal, (b) an active remote re

A ranging system comprising: (a) first means for transmitting a first continuous wave (CW) signal for a predetermined period of time, and for generating a second CW signal for a predetermined period of time at a frequency which is a very large fraction of the first CW signal, (b) an active remote reflector for generating and transmitting a first reflection signal at least initially in phase at the reflector with the first CW signal, and for generating and transmitting a second reflection signal initially in phase at the reflector with the second CW signal following transmission of the second CW signal, (c) means at the first means for receiving the first reflection signal and comparing its phase with the phase of the first CW signal whereby an apparent distance between the first means and reflector can be determined, (d) means at the first means for receiving the second reflection signal and comparing its phase with the second CW signal, and (e) means at the first means for providing a distance indicating signal corresponding to a result obtained by subtracting the phase differences of the first CW signal and received first reflection signal and the second CW signal and received second reflection signal and multiplying the result by the wavelength of the first CW signal divided by the difference between the wavelength of the first CW signal divided by the difference between the wavelengths of the first and second CW signal, the distance indicating signal representing an integral number of wavelength in excess of a fraction at which the first means is distance from said remote reflector.