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Radio-magnetic indicator (RMI)
An aircraft RMI
A radio-magnetic indicator (RMI) is an alternate ADF display providing more information than a standard ADF. While the ADF shows relative angle of the transmitter with respect to the aircraft, an RMI display incorporates a compass card, actuated by the aircraft's compass system, and permits the operator to read the magnetic bearing to or from the transmitting station, without resorting to arithmetic.
Most RMI incorporate two direction needles. Often one needle (thicker or double-barred) is connected to an ADF and the other (generally the thin, single-barred needle) is connected to a VOR. Using multiple indicators a navigator can accurately fix the position of their aircraft without requiring station passage. There is great variation between models and the operator must take care that their selection displays information from the appropriate ADF and VOR.