Abstract: A device for checking the consistency of a positioning includes: a transmitter, a receiver, a time measuring unit, a distance determining module and a check module. The transmitter emits at least one signal, and the receiver receives at least four response signals from at least four different response elements. A response element receives the at least one signal and, upon receipt, emits a response signal. The time measuring unit determines, for each response signal, a total delay time from a transmission time of the signal and a reception time of the respective signal. The distance determination module determines a distance to the respective response element based on each total delay time, and the check module performs a consistency check of a determination of a position based on distances to the different response elements. With the device, erroneous distance values may be detected in ground-based positioning systems.

Abstract: A device for checking the consistency of a positioning includes: a transmitter, a receiver, a time measuring unit, a distance determining module and a check module. The transmitter emits at least one signal, and the receiver receives at least four response signals from at least four different response elements. A response element receives the at least one signal and, upon receipt, emits a response signal. The time measuring unit determines, for each response signal, a total delay time from a transmission time of the signal and a reception time of the respective signal. The distance determination module determines a distance to the respective response element based on each total delay time, and the check module performs a consistency check of a determination of a position based on distances to the different response elements. With the device, erroneous distance values may be detected in ground-based positioning systems.

Abstract: An aircraft navigation system and navigation method. The system comprises a civil-certified GPS-receiver for determining first position information based on C/A-GPS-signals, and a military-type GPS-receiver for determining a second position information based on P(Y)-GPS-signals. A monitoring unit detects a first abnormal condition during jamming conditions within the C/A-GPS-signals. The unit compares the first position information with the second position information and detects a second abnormal condition when a difference between these position information is larger than a threshold value for more than a threshold duration. Upon detecting an abnormal condition, an alert procedure is initiated. In remotely piloted aircraft, Command & Control link-loss is also monitored and during link-loss, a transponder code automatically indicates communication failure.

Abstract: An aircraft navigation system and navigation method. The system comprises a civil-certified GPS-receiver for determining first position information based on C/A-GPS-signals, and a military-type GPS-receiver for determining a second position information based on P(Y)-GPS-signals. A monitoring unit detects a first abnormal condition during jamming conditions within the C/A-GPS-signals. The unit compares the first position information with the second position information and detects a second abnormal condition when a difference between these position information is larger than a threshold value for more than a threshold duration. Upon detecting an abnormal condition, an alert procedure is initiated. In remotely piloted aircraft, Command & Control link-loss is also monitored and during link-loss, a transponder code automatically indicates communication failure.