Devices and methods for testing altimeters are provided. A radio-frequency (RF) signal may be received from an altimeter and passed through an RF delay module to delay the RF signal. The delayed RF signal may be converted to an optical signal, which may be passed through an optical delay module to delay the optical signal. The system tests the accuracy of the altimeter based on the combined RF signal delay and optical signal delay.

Systems and method of calibrating a range measurement system for a vehicle mounted on a guideway are disclosed. In some embodiments, a method includes: measuring a first time of transmission (TOT) between a first internal component of an on-board range measurement device and a second internal component of a wayside range measurement device. The first TOT is compared with a first pre-determined time. A health of the range measurement system is determined based on a difference between the first TOT and the first pre-determined time.

A Time Domain Return measurement system for measuring liquid level, linear movement or other measurements which includes a first and second electrode, the second electrode spaced from the first electrode to define a gap, and an electronics assembly connected to the first and second electrodes equipped with a generator for transmitting an electromagnetic signal for propagation along the electrodes. The signal generator has a first analog timing circuit for actuating a slow-rising function of voltage versus time, a second analog timing circuit associated with the first analog timing circuit for actuating a fast-rising function of voltage versus time, and a receive circuit electrically connected to the electrodes, the receive circuit being activated for receiving return echo data associated with the electromagnetic signal transmitted when the fast-rising function is equal or greater than the slow-rising function to determine the position of the second medium with respect to the electrodes.

A Time Domain Return measurement system for measuring liquid level, linear movement or other measurements which includes a first and second electrode, the second electrode spaced from the first electrode to define a gap, and an electronics assembly connected to the first and second electrodes equipped with a generator for transmitting an electromagnetic signal for propagation along the electrodes. The signal generator has a first analog timing circuit for actuating a slow-rising function of voltage versus time, a second analog timing circuit associated with the first analog timing circuit for actuating a fast-rising function of voltage versus time, and a receive circuit electrically connected to the electrodes, the receive circuit being activated for receiving return echo data associated with the electromagnetic signal transmitted when the fast-rising function is equal or greater than the slow-rising function to determine the position of the second medium with respect to the electrodes.

A testing device for testing a distance sensor includes a receiving element for receiving an electromagnetic free-space wave as a receive signal, and a radiating element for radiating a simulated reflection signal. The receive signal or a signal derived therefrom is routed via a time delay circuit, and is thus time-delayed to a time-delayed signal. The time-delayed signal or a signal derived therefrom is radiated as the simulated reflection signal. The time delay circuit has an analog delay path and a digital delay path. The analog delay path implements shorter time delays than the digital delay path, apart from a possible overlap region. An input switch is used to switch the receive signal or the signal derived therefrom to the input of the analog delay path or to the input of the digital delay path, and the signal becomes the time-delayed signal after passing through the connected delay path.

A Time Domain Return measurement system for measuring liquid level, linear movement or other measurements which includes a first and second electrode, the second electrode spaced from the first electrode to define a gap, and an electronics assembly connected to the first and second electrodes equipped with a generator for transmitting an electromagnetic signal for propagation along the electrodes. The signal generator has a first analog timing circuit for actuating a slow-rising function of voltage versus time, a second analog timing circuit associated with the first analog timing circuit for actuating a fast-rising function of voltage versus time, and a receive circuit electrically connected to the electrodes, the receive circuit being activated for receiving return echo data associated with the electromagnetic signal transmitted when the fast-rising function is equal or greater than the slow-rising function to determine the position of the second medium with respect to the electrodes.

A system for estimating a substance level in a storage unit is disclosed. In one embodiment, the system includes a cable and a control device. The control device sense pulses down the cable and based on the time of reflected pulses determines the level of substance in the storage unit.

A radar system includes a transmitter including a power amplifier (PA) for amplifying a local oscillator (LO) signal, to generate an amplified signal. The radar system also includes a receiver including an IQ generator for generating an I signal based on the LO signal and for generating a Q signal based on the LO signal and a low noise amplifier (LNA) for amplifying a looped back signal, to generate a receiver signal. The receiver also includes a first mixer for mixing the receiver signal and the I signal, to generate a baseband I signal and a second mixer for mixing the receiver signal and the Q signal, to generate a baseband Q signal. Additionally, the radar system includes a waveguide loopback for guiding the amplified signal from the transmitter to the receiver as the looped back signal.

A transceiver for a detection and ranging apparatus comprising: a transmitter chain comprising a first sequence generator configured to generate a first signal based on a digital sequence; an interference cancellation block comprising a second sequence generator configured to generate a second signal based on the same digital sequence used to generate the first signal, the second signal having a predetermined time delay relative to the first signal; and the receiver chain configured to receive a received signal for detection and ranging, the received signal having components comprising at least none, one, or more reflections of the transmission signal and a component comprising an interference signal, the receiver chain comprising a first analog signal mixer configured to provide an output signal by mixing the received signal and the second signal thereby cancelling the interference signal in the received signal.

Devices and methods for testing altimeters are provided. A radio-frequency (RF) signal may be received from an altimeter and passed through an RF delay module to delay the RF signal. The delayed RF signal may be converted to an optical signal, which may be passed through an optical delay module to delay the optical signal. The system tests the accuracy of the altimeter based on the combined RF signal delay and optical signal delay.