CHandra's Atmospheric Composition Explorer-2 (CHACE-2) is a neutral gas mass spectrometer aboard Chandrayaan-2 orbiter. CHACE-2 is a quadrupole based mass spectrometer which detects neutral atoms/molecules in the mass range of 1-300 amu. The data product from CHACE-2 observations provide the partial pressure for different masses that essentially constitute the mass spectra. CHACE-2 scans different masses using suitable voltages such that each mass is contributed by nine mass bins, known as samples. Each spectrum (mass along x -axis and partial pressure along y-axis) is constructed based on these 9 samples, where the fifth sample is expected to be at the center of the peaks. During the actual measurements in space, mass shifts have been observed such that the center of the peaks doesn't coincide with the expected mass bin, but rather shifted to either lower or higher mass bins. Also, the 9 samples that determines the peak shape need not follow the expected pattern. Suitable criteria have been arrived at in order to verify the quality of each spectrum. In view of the large data sets, an algorithm has been developed to determine and calibrate the mass shift, verify the quality of the spectrum based on the criteria and generate suitable flags in the output file. The algorithm is referred to as 'Peak Filter Algorithm'. The output of the algorithm has been validated and the output has been found to be matching with that expected. The details of the algorithm along with the validation results are presented in this paper. The output of the algorithm is significant for the scientific analysis of CHACE-2 data, and also useful for the analysis of data from instruments similar to that of CHACE-2 in future missions.

来源平台：INTERNATIONAL JOURNAL OF MASS SPECTROMETRY