A Preliminary Analysis of the NPP CrIS Spectral Noise

The spectral noise of NPP CrIS is analyzed with the probationary data generated by the interface data processing segment (IDPS). Two methods, principal component analysis (PCA) and moving window standard deviation (MWSD) are applied. Preliminary analysis indicates that the instrument has excellent performance. In most cases, the noise level is well below the specification even though it is slightly affected by the target brightness temperature. It is also found that the noise from PCA is slightly lower than that from MWSD as the later one is impacted by the non-stationary feature of the internal hot target.