GPM DPR Ka Precipitation Profile 2A 1.5 hours 5 km V07 (GPM_2AKa) at GES DISC

Version 07 is the current version of the data set. Older versions will no longer be available and have been superseded by Version 07.

The 2AKa algorithm provides precipitation estimates from the Ka radar of the Dual-Frequency Precipitation Radar on the core GPM spacecraft. The product contains two swaths of data corresponding to the scans of the Ka radar. The first swath contains matched scans (MS), which are intended to be co-aligned with the Ku-band instantaneous fields of view (IFOV). The second swath contains the high-sensitivity scans (HS), which are interleaved between the Ku/Ka-MS swaths. Both swaths are narrow and centered within the interior of the Ku swath. This is a single-frequency retrieval of precipitation; no information from the Ku radar is used. The retrievals are performed at each radar range bin along the slant path of the radar IFOV for each swath.

This is a single-frequency retrieval that relies on Ka-band data only. While the dual-frequency retrieval should give better overall estimates, that algorithm requires co-aligned Ku-band data. This 2AKa product will be produced independently and would not be impacted by any operational issues with the Ku-band radar. The high sensitivity to smaller hydrometeors should result in precipitation estimates in lighter precipitation then the Ku-only data.

It is important to note the difference between the single- and the dual-frequency (DF) algorithms. While this 2AKa dataset is a single-frequency retrieval, the DF algorithm employs both KuPR and KaPR L1B standard products as inputs. The DF algorithm cannot be executed unless both L1B products are available. Pixels observed by DPR can be categorized into three types: pixels in the inner swath of normal scans (observed both by KuPR and KaPR), pixels in the outer swath of normal scans (observed only by KuPR), and pixels in the interleaved scans (observed only by KaPR in the high-sensitivity mode). The KuPR algorithm is executed for pixels in both inner and outer swaths of normal scans. The KaPR algorithm is executed for pixels in the inner swath of normal scans and in the interleaved scans. The DF algorithm is executed for pixels of all the three kinds.