Rocket Electron Density Perturbations in the Ionosphere

Abstract

IN an experiment on radio propagation which is currently being flown in the British Skylark rocket, pulse signals on frequencies in the range 2–10 Mc/s are radiated from a ground based transmitter T (Fig. 1) and the pulse pattern received at the rocket R is telemetered back to ground. An additional very high frequency (104 Mc/s) pulse is also radiated from the ground and received at the rocket so that both the true path and group path are measured simultaneously. Pulse patterns are recorded at 1/50 sec intervals throughout flight and provision is made for switching to different selected frequencies when required. Time base scans on coarse and fine scales enable the overall pattern to be studied and the time separation between the various pulses to be measured accurately. A typical pulse pattern is shown in Fig. 2a which for clarity is reproduced as a line tracing in Fig. 2b. In this example, pulse A is the VHF 104 Mc/s signal, pulse B the direct HF (3.6 Mc/s) signal and the broader pulse C is the indirect echo signal reflected from the F layer.