Chirp signals have established diverse applications caused by the capable of producing time-dependent linear frequencies. Most feature extraction transformation methods for chirp signals focus on enhancing the performance of transform methods but neglecting the information derived from the transformation process. Consequently, they may fail to fully exploit the information from observations, resulting in decreased performance under conditions of low signal-to-noise ratio (SNR) and limited observations. In this work, we develop a novel postprocessing method called "mapping information model" to addressing this challenge. The model establishes a link between the observation space and feature space in feature extraction transform, enabling interference suppression and obtain more accurate information by iteratively resampling and assigning weights in both spaces. Analysis of the iteration process reveals a continual increase in weight of signal samples and a gradual stability in weight of noise samples. The demonstration of the noise suppression in the iteration process and feature enhancement supports the effectiveness of the mapping information model. Furthermore, numerical simulations also affirm the high efficiency of the proposed model by showcasing enhanced signal detection and estimation performances without requiring additional observations. This superior model allows amplifying performance within feature extraction transformation for chirp signal processing under low SNR and limited observation conditions, and opens up new opportunities for areas such as communication, biomedicine, and remote sensing.