Striping Noise Mitigation for Tropical Rainfall Measuring Mission Microwave Imager Observations

The conical-scanning Tropical Rainfall Measuring Mission Microwave Imager (TMI), which plays an important role in monitoring global precipitation, has nine channels. A clear striping noise feature is found in pitch-over maneuver data of deep-space and earth-view observations at all nine channels of the TMI. A modified striping noise mitigation algorithm is used to extract the striping noise from deep-space and earth-scene observations. The magnitude of the striping noise extracted from TMI channel 10.65 V, 10.65 H, and 37.0 H measurements is about 0.4 K and more than 1.5 K for channel 85.5 V and 85.5 H measurements. After striping noise mitigation, no visible striping feature is seen in the observation-minus-simulation distributions of both deep-space and earth-scene brightness temperatures. Comparisons of the liquid water path (LWP) retrieved from TMI brightness temperatures with and without striping noise mitigation show that the striping noise in brightness temperatures results in a striping feature in LWP retrievals. When the striping noise is not removed from TMI observations, LWP retrievals exhibit a cross-track striping feature. The striping noise leads to a greater retrieval difference in larger LWP areas.