Provided are methods and systems for measuring and controlling nozzle areas of variable area fan nozzles. A control system attached to a nozzle includes a cable having one end connected to a linear displacement measuring device, such as a string potentiometer. The other end of the cable is connected to a petal. A reference portion of the cable extends across multiple petals of the nozzle and substantially parallel to the nozzle circumference. The linear displacement measuring device measures any changes in the length of this reference portion as the petals actuate outwardly or inwardly during operation of the nozzle. The output of the linear displacement measuring device may be used to control actuators that move the petals. In some embodiments, potentiometer's output may be combined with one or more outputs from other sensors, such as a linear variable differential transducer and/or thermocouple.