National Aeronautics and Space Administration

Aquarius Validation Data System Overview and StatusAlgorithm Workshop March 21-22, 2007

John Gunn

Earth & Space Research

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

The Aquarius Validation Data Segment (AVDS) will collect and process surface measurements for Aquarius data processing

Deliver surface calibration data to Aquarius Data Processing Segment (ADPS)

• Liaison with observers• Daily data acquisition• Quality control/editing• Uniform data format

Task Leader: John GunnJohn Gunn

AVDS

Aquarius Validation Program

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

In-situ data

AVDSESR

AVDSESR

ADPSGSFC

ADPSGSFC

USERS

GTSPP

Validation data

Via ftpdaily

AVDS/ADPS Interaction

Match up with Aquarius beams for calibration

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

AVDS Structure

AVDSServer(ESR)

DataFilters

DBMS

ADPS(GSFC)

ADPS(GSFC)

AVDSTextfiles

AVDSTextfiles

SatelliteHDFfiles

SatelliteHDFfiles

AlignedDatafiles

AlignedDatafiles

Tabulatedfiles

Tabulatedfiles

Userrequests

Userrequests

Webinterface

Webinterface

In situdata

In situdata

Primary data path

Red implies GSFCBlue implies ESR

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

In situ data filters

• Evaluate data for inclusion based on depth, QC flags

• Duplicate data removed

• At present, chooses daily data two weeks prior to real-time

• Time and space selection limits specified (method TBD)

• Formats data into text file for uploading by ADPS

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

AVDS text file format example

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

3 beams, 76 x 94, 84 x 120, 96 x 156 km instantaneous footprint ellipses across the 390 km wide swath.

390 km Orbit Spacing

Match-up Scheme

Buoy Obs.

Buoy Obs.

Search Radius

Search Radius

Match-up processing

• One match-up file per buoy observation contains all the satellite data in the search radius

• Subsequent processing to generate the optimal weighted average satellite observation per buoy

• Global tabulations

Match-up processing

• One match-up file per buoy observation contains all the satellite data in the search radius

• Subsequent processing to generate the optimal weighted average satellite observation per buoy

• Global tabulations

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

Match-up Data Processing

• Run on ESR data server

• Uses inputs from AVDS text file and subsequently generated satellite data file (HDF)

• Process data from each beam and variable separately

• Perform a weighted average of the pass data centered on the CPA

• Weighting function shall be Gaussian with e-folding radius half of Aquarius beam width

• Weighting function to be evaluated through subsequent analysis

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

Database Management System

• Structured similar to SeaBASS functionality

• SQL based relational database

• Search and retrieve capability for in situ, match-up data and originating data by time, geo-location, original platform characteristics and other TBD metadata.

• Source information for original data may be specified rather than actual data

• Web-based interface

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

AVDS - Recent Accomplishments

• Ongoing liaisons with DAC’s

• Completion of AVDS/ADPS ICD

• Transfer of real-time ARGO float data to ADPS

• Recovery of matched up MODIS SST data to AVDS

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

AVDS - On-going Elements

• Definition of key functional requirements (document in progress)

• Draft AVDP Plan in preparation

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21-22 March, 2007Aquarius Algorithm WorkshopAVDS: J. Gunn

Upcoming Tasks

• Definition and procurement of RDBMS software

• Specification of AVDS dedicated data server (disk space requirements, etc.)

• Web site development