Data News

IMERG is now available back to June 2000 of the TRMM era.  Both the 'early'
and the 'late' products have been retrospectively processed.  These products are available in the same location on the jsimpson.pps.eosdis.nasa.gov FTP server as the current GPM IMERG products: /NRTPUB/imerg/early/YYYYMM and /NRTPUB/imerg/late/YYYYMM.

We are in the process of retrospectively processing the GIS-friendly versions and accumulations of these IMERG products. This is likely to be completed by the end of September 2019.

               **IMPORTANT**

A very important item is that we have been directed to eliminate ftp to all our servers. We know that many of you have scripts that automatically retrieve data.  PPS is attempting to impact you as little as possible. We are putting up an FTPS server.  This means that as long as you have a client that support FTPS you should be able to use almost extactly the same commands as you currently use.

We will soon announce a public access to this FTPS server. You can then test new FTPS scripts against the FTPS server in parallel with continued retrieval using ftp (thereby not interrupting your operational flow).  We hope to be able to provide this parallel access for six months. After 6 months we will be required to eliminate FTP totally.

Please contact us for any questions.
 

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PPS has completed the retrospective processing of IMERG NRT early and late products to version V06B.

All GPM NRT IMERG is available at version V06B from June 2014 through the current IMERG data.

The GPM NRT IMERG from March 2014 through May 2014 will be available once the TRMM era (2000-2014) retrospective processing is completed.

THe V06B data is the default product (early and late) available on the jsimpson.pps.eosdis.nasa.gov NRT file server.

Please contact us for any questions.

 

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On 16 June 2019 at 22 UTC several hours of missing IR data and subsequent handling of this outage caused IMERG early and late products to be produced without IR data since that date/time.  To ensure consistent early and late IMERG products it was decided to retroprocess these IMERG early and late products.

All early and late IMERG products from 16 June 2019 at 22:00 UTC through June 19 were retroprocessed. You may wish to download the revised products from 16 June 2019 22:00 UTC  onword.

IMERG early and late are being produced again at their required latency: 
    a. early: approx 4 hours from data collection
    b. late:  approx 14 hours from data collection

We are sorry for the extended unavailability of the products. 
 

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Effective around 12:00 UTC 10 June the MHS and ATMS input to real-time IMERG suddenly became unavailable due to an unexpected change in NOAA protocols.  While PPS scrambles to remedy the issue, the data content of the Early and Late Runs may be reduced for the next several days, meaning lower Quality Index due to longer morphing of microwave estimates and greater contributions by IR.

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Due to a correction to the GPM IMERG algorithm implemented by the GPM science team, PPS will retract and reprocess all IMERG V06A Final Run GPM and TRMM era data including GIS products as IMERG V06B starting on June 05, 2019.  If you have downloaded IMERG V06A Data previously, please discard this data and use the improved IMERG V06B products as they are produced and archived.

A damaged land/ocean mask file (specifically, a several-gridbox shift to the east and south) was discovered in IMERG V06A,which causes mis-identification of surface type along coasts in theKalman filter computation. While simple to correct, the change in the IMERG results requires shifting to a new sub-version. As of May 22, 2019, the IMERG NRT Early and Late Run files were given the corrected land/ocean mask file and labelled V06B.  The adjustment can be seen in the Early and Late data files starting with June 1, 2019 when the next Kalman statistics were computed.

As was done for V06A, PPS will start the V06B reprocessing with the GPM era, June 2014 - current available data.  This reprocessing will include the GIS products. Once the GPM era is completed, we will start the TRMM-era, June 2000 - May 2014. We will issue necessary update messages as our re-processing effort progresses. The schedule for completing all IMERG V06B processing is not currently known, but will need to reflect balancing the reprocessing with other production computing requirements.

The new V06B TRMM/GPM data products will be made available through PPS's "arthurhou" ftp archive:
ftp://arthurhou.pps.eosdis.nasa.gov/

and STORM (PPS's Online Data Ordering Interface):
https://storm.pps.eosdis.nasa.gov
after the products are produced and archived.

NASA requires that all science data users register in order to access these products.  If you haven't registered, please visit the PPS registration portal at:https://registration.pps.eosdis.nasa.gov/registration/

We apologize for any inconvenience this may have caused and thank you for your attention.  Please inform us if you have any questions or concerns.
 

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All IMERG V06A Final products will be retracted later today.  

On Wednesday, June 5, PPS will start the V06B reprocessing beginning with the GPM era, June 2014 - current available data.  Once the GPM era is completed, PPS will start the TRMM-era, June 2000 - May 2014.

Due to capacity loads at PPS, there are no firm estimates as to how long this will take. 

V06A is being retracted due to a corrupt surface coverage file in the Kalman statistics computation.  

Please contact us for any questions.

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A damaged land/ocean mask file (specifically, a several-gridbox shift to the east and south) has been discovered in IMERG V06A, which causes mis-identification of surface type along coasts in the Kalman filter computation.  While simple to correct, the change in the IMERG results requires shifting to a new sub-version.  As of May 22, the Early and Late Run files have the corrected land/ocean mask file and are labelled V06B.  The adjustment will be seen in the Early and Late data files starting June 1, when the next Kalman statistics are computed.  Final Run retrospective processing for V06B will begin shortly; more information will be forthcoming.

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PPS will be updating GPM 1AGMI data from V05A to V05B today, Thursday May 09, 2019 because there was a minor bug in the algorithm.  Only 1AGMI will change versions.

The L1AGMI executable was previously not filling in a missing scan if there was an error in reading or processing the scan data from the instrument.  Nothing was being generated in the GMI 1A product in this case.  The bug fix was to fill in a missing scan and annotate this in the file header.


+-------+----------------+---------------------+-------+
| AlgId | ProductVersion | StopTime            | SeqNo |
+-------+----------------+---------------------+-------+
| 1AGMI | V05A           | 2019-05-09 12:28:13 | 29508 |
+-------+----------------+---------------------+-------+

Data will be updated to V05B starting with:

+-------+----------------+----------------------+-------+
| AlgId | ProductVersion | StartTime            | SeqNo |
+-------+----------------+----------------------+-------+
| 1AGMI | V05B           | 2019-05-09 12:28:14  | 29509 |
+-------+----------------+----------------------+-------+

PPS replaced one  1AGMI file for orbit 29457 (2019-05-06 04:13:43 ->
2019-05-06 05:46:18)  which was retro-processed as a V05B data product.

1A.GPM.GMI.COUNT2016.20190506-S041343-E054618.029457.V05A.HDF5 - V05A
1A.GPM.GMI.COUNT2016.20190506-S041343-E054618.029457.V05B.HDF5 - V05B
 

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On 1 May 2019, at approximately 14 UTC, PPS will stop production of IMERG V05 in order to setup and install the new IMERG V06 code for production of early and late products.

This will require an extended period when no IMERG products will be produced or available for users. We estimate an extended period of IMERG unavailability that may last for 5 hours or more.

Upon resumption of IMERG production, V06 will start with data from 1 May
2019 hour 00 UTC. We will reestablish latency of early products to 4 hours, and late products to 14 hours, as soon as possible.

We will also start V06 retro-processing of IMERG early and late products back to the beginning of the GPM mission. These will be available on the server as they are produced.

Please contact us for any questions.
 

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An error has been 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.  [Masking for microwave retrievals over surface snow and ice outside that band is correct.]

All V06A Monthly and Half-hourly IMERG products are being retracted, as shown in this table (Encompassing all IMERG V06A data that had been reprocessed and archived -to date):

----------+----------------+---------------------+---------------------+------------+---------+--------------+ 

| DataType | ProductVersion | Start of Data       | End of Data # 
| Granules | # Empty | Total Size   |
+----------+----------------+---------------------+---------------------+------------+---------+--------------+ 

| 3IMERGHH | V06A           | 2014-06-01 00:00:00 | 2015-12-31 23:59:59
|      27792 |       0 |     273.23 G |
| 3IMERGM  | V06A           | 2014-06-01 00:00:00 | 2015-12-31 23:59:59
|         19 |       0 |       0.93 G |
+----------+----------------+---------------------+---------------------+------------+---------+--------------+ 


Replacements are anticipated to be released the week of March 25, and will continue to be named V06A since the retracted files are considered faulty.

If you have previously obtained any of the data listed above, please discard these and replace this data with the new data once this is available the week of March 25 or later.

We apologize for any confusion or inconvenience that this may have caused and appreciate your continued patience.
 

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