Development of VLF receiver for remote sensing of low atmospheric activities

VLF (very low frequency) can be used to probe lower atmospheric activities. To detect lower atmospheric activities, two types of VLF receiver were developed in this project. The first type is called SID (sudden ionospheric disturbances) receiver which is used to detect the solar flares activities that affect communication systems. The second one is called natural radio receiver which is used to detect natural radio signals such as sferics, whistlers emitted by the activities of lightning discharges. A wire loop antena was developed to receive VLF signals from outer space for the receivers that has been developed. In the process of developing the VLF receiver, MULTISIM software. It was used to simulate the receiver´s circuit developed for this purpose. The simulation results was adopted to design a prototype for the circuit for experiments carried out to measure the performance and the ability of the receivers in receiving VLF signals. Lab equipment, such as signal generators and oscilloscopes, were used to test the performance of the receivers. The receivers developed will contribute to the research of D-layer ionospheric activities.