Mass analyzers and methods of ion detection for a mass analyzer are provided. An electrostatic field generator provides an electrostatic field causing ion packets to oscillate along a direction. A pulse transient signal is detected over a time duration that is significantly shorter than a period of the ion oscillation or using pulse detection electrodes having a width that is significantly smaller than a span of ion harmonic motion. A harmonic transient signal is also detected. Ion intensity with respect to mass-to-charge ratio is then identified based on the pulse transient signal and the harmonic transient signal.