Documents

Date Last Updated
April 30th, 2021
Document Description

To address how NASA data can enable support of operations within the transportation and logistical sectors, the NASA Global Precipitation Measurement (GPM) Mission Applications Team, in collaboration with the Aerosols, Clouds, Convection and Precipitation (ACCP) Study Applications Impact Team (AIT), organized the virtual 2020 NASA GPM-ACCP Transportation and Logistics Workshop

Date Last Updated
January 15th, 2021
Document Description

NASA information security management authorities mandated that continued use of the File Transfer Protocol (FTP) should not be allowed, even when used to provide access to publicly-available, non-sensitive information. This decision was made because FTP login credentials are sent in clear text. For this reason, they mandated that all FTP sites either convert to some form of encrypted login mechanism or be shut down.

Date Last Updated
January 15th, 2021
Document Description

At the end of 2020, PPS anticipates that it will replace the current FTP access to its Production data archive with FTPS and HTTPS access. In choosing between FTPS and HTTPS, select HTTPS in situations where firewall restrictions prevent FTPS access.

Date Last Updated
January 15th, 2021
Document Description

NASA information security management authorities mandated that continued use of the File Transfer Protocol (FTP)
should not be allowed, even when used to provide access to publicly-available, non-sensitive information. This decision
was made because FTP login credentials are sent in clear text. For this reason, they mandated that all FTP sites either
convert to some form of encrypted login mechanism or be shut down. PPS determined, after reviewing available

File Downloads
Date Last Updated
January 15th, 2021
Document Description

At the end of 2020, PPS anticipates that it will replace the current FTP access to its Production data archive with FTPS and HTTPS access. In choosing between FTPS and HTTPS, select HTTPS in situations where firewall restrictions prevent FTPS access.

Date Last Updated
October 6th, 2020
Document Description

The algorithm for the Integrated Multi-satellitE Retrievals for GPM (IMERG) has now been upgraded to Version 06. The transition to V05 for the IMERG Final Run began 13 March 2019 at PPS and the new data started flowing down to the GES DISC as well. However, on 15 March 2019 an error was discovered in processing the initial batches of V06 IMERG Final Run months. A design choice in the code ended up retaining microwave precipitation estimates in the latitude band 60°N-S when there is snow/ice on the surface, rather than masking out the estimates due to low performance in such cases.

Date Last Updated
October 6th, 2020
Document Description

In IMERG up through V05, the cloud motion vector computation approach used is that pioneered in CMORPH (Joyce et al. 2011), in which motion vectors are computed from 4-km geosynchronous infrared (GEO-IR) brightness temperatures. Hence, the motion vectors reflect cloud top motions. However, there are two main limitations in using GEO-IR. The first limitation is that cloud top motions may not match precipitation motions due to both wind shear and the growth and decay of precipitation systems.

Date Last Updated
October 6th, 2020
Document Description

The Integrated Multi-satelliE Retrievals for GPM (*IMERG*) is the unified U.S. algorithm that provides the multi-satellite precipitation product for the U.S. GPM team.  The precipitation estimates from the various precipitation-relevant satellite passive microwave (PMW) sensors comprising the GPM constellation are computed using the 2017 version of the Goddard Profiling Algorithm (GPROF2017), then gridded, intercalibrated to the GPM Combined Radar Radiometer Analysis product (with GPCP climatological calibration), and combined into half-hourly 0.1°x0.1° fields.

File Downloads
Date Last Updated
October 2nd, 2020
Document Description

The transition from the Tropical Rainfall Measuring Mission (TRMM) data products to the Global Precipitation Measurement (GPM) mission products has begun. This document specifically addresses the multi-satellite products, the TRMM Multi-satellite Precipitation Analysis (TMPA), the real-time TMPA (TMPA-RT), and the Integrated Multi-satellitE Retrievals for GPM (IMERG).

Date Last Updated
April 22nd, 2020
Document Description

NASA produces a GIS translation of IMERG for various accumulation periods that maintains the 0.1-degree resolution and global coverage of the original HDF5 data product. In April 2019, Version 6 of IMERG was released in both the HDF5 and the GIS formats. Version 6 is the first version to cover the approximately 20-year period from June 2000 to the present. This long-duration archive will be a boon to scientific research and will provide an expanded training set for realtime applications such as disaster monitoring.