global precipitation measurement (gpm) mission data and data access

1EGU 2014-Vienna Austria, April 30, 2014

Erich Franz Stocker ([email protected])PPS Project Manager/Software ArchitectGPM Deputy Project Scientist for Data

Global Precipitation Measurement (GPM) Mission Data and Data AccessNASA Precipitation Processing System (PPS)


GPM Key Data Dates• February 28, 2014 3:30AM (JST) GPM Core Observatory

launch from Tanegashima Space Center, Japan• March 4, 2014 GMI commanded to science observation

mode and first data received• March 8, 2014 DPR commanded to science observation

mode and first data received• March 21, 2014 GMI L1, L2 near-realtime (NRT) and L1,

L2, L3 science standard data made available to set of early data adopters

• April 2, 2014 DPR L2 NRT and L2 and L3 science standard data made available to set of early data adopters

• April 2, 2014 Combined GMI/DPR L2 NRT and L2 and L3 science standard data made available to set of early data adopters

• Current GMI, DPR and Combined data version is V01D both NRT and standard science


Data Release

• End of June 2014 GMI data release to the international Precipitation Measurement Missions (PMM) science team

• End of July 2014 DPR data release to the international PMM science team

• End of August 2014 General public release • End of November 2014 General public release of new

merged radiometer product (IMERG)


NRT GPM Core Data Products

Processing Level

Sat/Inst/Alg Size Latency Key Parameters

1B GPM/GMI 5 min <= 1Hr 90% Brightness Temperature-Tb

1C GPM/GMI 5 min <=1Hr ,90% Tb (future 1C reference)

1CR GPM/GMI 5 min <- 1Hr, 90% Intercalibrated Tb with matched HF and LF pixels

2A GPM/GMI/GPROF 5 min <=1Hr 90% Precipitation/TPW

2A Ku GPM/DPR/Ku 30 min

<=180 min Reflectivities/3D Precipitation

2A Ka GPM/DPR/Ka 30 min

<=180 min Reflectivities/3D Precipitation

2A DPR GPM/DPR/DPR 30min <= 180min Dual Frequency retrievals: reflectivities/3D

precipitation2B

GMI/DPRGPM/GMI-DPR 30

min<=180 min 90% Combined GMI/DPR

retrieval. 3D Precipitation3 Merged

Radiometers/IRHalf-hour

Early – 4 hoursLate – 8 hours

.1 deg x .1 deg global surface precipitation


1CR


NRT Constellation Products

Processing Level

Sat/Inst/Alg Size Latency Key Parameters

1C Metop B/MHSNoaa 18/MHSNoaa 19/MHS

As receive

d

Provider dependent

Intercalibrated Tb

1C MT/SAPHIR As receive

d

Provider Intercalibrated Tb

1C NPP/ATMS 1 Hr Provider Intercalibrated Tb

1C F16/SSMISF17/SSMISF18/SSMIS

As receive

d

Provider Intercalibrated Tb

1C TRMM/TMI TDRSS <=180 min Reference Tb1C GCOM-W/AMSR2 orbit ~120min Intercalibrated Tb2A GPROF /MHS

SAPHIRATMSSSMIS

TMIAMSR2

Same as 1C

Same as 1C Precipitation/TPW


Standard GPM Core Science Swath Products

Processing Level

Sat/Inst/Alg Size Key Parameters

1B GPM/GMI GPM orbit (Gorbit*)

Brightness Temperature-Tb

1C GPM/GMI Gorbit Tb (future reference)1CR GPM/GMI Gorbit Tb with matched HF and

LF footprint2A GPM/GMI/GPROF Gorbit Precipitation/TPW

2A Ku GPM/DPR/Ku Gorbit Reflectivities/3D Precipitation

2A Ka GPM/DPR/Ka Gorbit Reflectivities/3D Precipitation

2A DPR GPM/DPR/ Gorbit Dual Frequency Retrievals. 3D precipitation

2B GMI/DPR

GPM/GMI-DPR Gorbit GMI-DPR retrieval. 3D Precipitation

* Gorbit is the GPM orbit calculated from the southern most point back to the southern most point


Standard GPM Core Gridded Products

Processing Level


3A GPM/GMI/GPROF 0.25 deg x 0.25 deg

Daily/monthly

Precipitation

3A GPM/DPR 0.25 deg x 0.25 deg

Daily

PrecipitationAscending/Descending

separate3A GPM/DPR 0.25 deg x 0.25

degMonthly

Precipitation

3B combined

GPM/GMI-DPR 0.25 deg x 0.25 deg

Daily/monthly

Precipitation

3B Merged Merged Radiometers 0.10 deg x 0.10 deg

Half-hr/monthly

Gauge adjusted global precipitation


Standard Constellation Data ProductsProcessing Level


1C Metop B/MHSNoaa 18/MHSNoaa 19/MHS

GPM orbit

(Gorbit)

Intercalibrated Tb

1C MT/SAPHIR Gorbit Intercalibrated Tb1C NPP/ATMS Gorbit Intercalibrated Tb

1C F16/SSMISF17/SSMISF18/SSMIS

Gorbit Intercalibrated Tb

1C TRMM/TMI Gorbit Reference Tb1C GCOM-W/AMSR2 Gorbit Intercalibrated Tb2A GPROF /MHS

SAPHIRATMSSSMIS

TMIAMSR2

Same as 1C

Precipitation/TPW

3A All instruments with GPROF 2A

Dailymonthl

y

0.25 deg x 0.25 degPrecipitation


Status of GPM Data Products-1• Geolocation

– Location on the ground reported within requirements– On April 19 Attitude Control System engineers reported an alignment error between

start tracker and spacecraft leading to ~0.3 degree peak to peak attitude error (mostly roll)• This does have an impact on incidence angles which affect Tb calculation• New table scheduled to be uploaded April 25• Data products will be adjusted as part of reprocessing for the PMM data release

• GMI L1 products– Reasonably well calibrated (meets requirements specifications)– Small calibration changes in April that included in version V01D– Close to TMI calibration– Some RFI issues in 10 GHz and 18GHz channels (approach to flag and mitigate

currently being examined.)• GPROF retrieval products

– Saw more specific information in Dr. Kummerow’s presentation– Currently using initial non GPM a priori databases – New database approach for over land retrievals working reasonably well– Currently producing GPROF retrieval for partner imagers and testing sounders– Early state: some areas during really well and others not – Will need about one year of stable GMI L1C and GMI-DPR Level 2B data to establish

physically based a priori databases for the GPROF retrievals for the radiometers


Status of GPM Data Products -2• Ku/Ka L1B –radar powers

– Have completed several external and internal calibrations– Have verified phase shifter commands– Reasonably well calibrated for this stage of the mission– Providing acceptable input for the radar L2 algorithms

• Ku/Ka/DPR-retrievals– L2 are providing reasonable retrievals again at the early stage where better in some

areas than in others– Matching of Ku/Ka pixels working – Some issues are being worked by JAXA engineers and DPR algorithm team

• Combined GMI-DPR– Very early stage of development– Working on dealing with data input issues– Currently still in the experimental stage

• IMERG (merged radiometer product)– Not being currently produced– Need stable GPROF retrievals for sounders as well as imagers– Currently in internal testing– Usually lags 3 to 4 months after stable L2 GPROF retrievals.


Sample Images of GMI and DPR


GPM Special Products• Daily gridded text products (like TRMM 3G68)

– 0.1 deg x 0.1 degree– Contains:

• GMI GPROF surface precipitation• Ku near-surface precipitation• Ka near-surface precipitation• DPR match swath near-surface precipitation• GMI-DPR Combined surface precipition

– ASCII with line terminator being LF character• GIS compatible files for IMERG

– TIFF (precipitation) with world files for metadata– Precipitation in TIFF is scaled integer– Half-hourly, 1day, 3 day and 7 day accumulations


Accessing GPM Data• Must register an email.

– registration.pps.eosdis.nasa.gov– Receive an email and click to confirm– Can specify interest in either standard science, NRT or both

• Can do ftp to the archive using your registered email as user name and password• Can use a query/order web interface

– storm-pps.gsfc.nasa.gov or storm-pps.pps.eosdis.nasa.gov– Can query, place orders for specific products, or establish standing orders which will

be fulfilled as products are generated– Can subset swath products and get only the subsets specified

• Geographically• Parameter (e.g. just include geolocation and surface precipitation)• Or both together• Currently limited as to the number orderable to keep within scope

– Can establish standing orders for subsets – Can see browse images of the orbit to help in ordering decisions– Can look through the data product online

• File specifications and algorithm theoretical basis documents (ATBD)– pps.gsfc.nasa.gov/GPMprelimdocs.html


Tools and Services• THOR

– Tool for looking at GPM data products – Includes functionality for making images including 3D images– IDL based but IDL not required– Available for: Linux, Windows, Mac OS– http://pps.gsfc.nasa.gov/thorrelease.html

• Subsetting available for multiple years (STORM currently limits) – [email protected]– [email protected]– Includes setting up subsets to support field campaigns

• 3 Hr Presentation (Data and data access)– Includes

• More detailed data description,strengths,limitations and status• HDF5 format and tools for accessing• Useful documentation• Accessing data including the writing of scripts for automated access• Use of THOR, STORM

– Can with planning offer the tutorial at Universities and agencies – After a couple of presentations to get user feedback will package the presentation– Contact: [email protected]

mailto:[email protected]

mailto:[email protected]

global precipitation measurement (gpm) mission data and data access

Documents

data receivedmarch

data releaseend

dpr data release

gmi data release

l3 science standard

early data adoptersapril

combined data version

early data adopterscurrent