# Presentation: 372557

## STEREO and the Virtual Heliospheric Observatory

- Tom Narock1,2     Adam Szabo1       Jan Merka2
- (1) NASA/Goddard Space Flight Center
- (2) L3 Communications, GSI
- http://vho.nasa.gov

**STEREO/Solar B Workshop - November, 2005    **

## Scientific Quest is Changing

- Past – In-depth single spacecraft studies
- Future – Study multi-spacecraft / multi-instrument  local and remote sensing measurements
- STEREO
- Multi spacecraft platform with remote and in-situ instruments
- Addresses large-scale heliospheric structures so it would uniquely benefit from other platforms

## Battle of WITS

**W**: Where to find data?
**  ****I**: Integration of data from various sources
-           is often difficult.
** ****T**: Tools are needed to work with the data.
** ****S**: Scientific perspective introduces
-           additional questions:
- Integration of distant heliospheric observations
- Time-space propagation (what is a match?)
- Integration of remote and in-situ measurements

## Why Virtual Observatories ?

- Many datasets with large volumes
- Data sites distributed worldwide
- Stored in a variety of formats
- Accessible through a wide variety of interfaces

## What is the goal of the VHO?

- Science based discovery of heliospheric data
- Unified, yet simple, environment to access all heliospheric data sets and tools
- Provide rapid community access to the highest quality processed data

## VHO Design

-  Existing data providers plus new Metadata descriptions of data and data products
-  SPASE dictionary
-  Data Synchronization

## VHO Design

- Addition of VHO Middleware

- Metadata synced to VHO

## VHO Design

## Initial VHO Data Participants 8 Spacecraft - 13 Data Sets

**ACE**
-  Magnetometer
-  SWEPAM

**Genesis**
-  Mag. Field Proxy
-  3D Moments

**Helios 1 and 2**
-  Magnetometer
-  Plasma instrument

**IMP 8**
- - Magnetometer

**SOHO**
- - Celias instrument

**                 ****WIND **
-                  - MFI
-                  - SWE
-                  - ELPD
-                  - PLSP

**Mars Global Surveyor**
- Solar Wind Pressure Proxy

## Addition of Instruments and Spacecraft Total: 12 Spacecraft - 30 Data Sets

**Messenger**
-  MAG
-  EPPS

**STEREO **
** ****IMPACT  - PLASTIC**

**Ulyssses**
** **VHM (mag field)
-  BAI (ions)
-  BAE (electrons)

**Voyager**
- - MAG

## Data Synchronization

**VHO Member**

**Data Recipient**

## Current Types of VHO searches

- Science driven data searches:
-       _Time_                             _Space_                     _Measurement_
-        1. Date/Time               1. GSE                   1. Magnetometers
-         2. Bartel Rotation       2. GSM                   2. SW Plasma
-                                            3. HGI                     3. Particles/Moments
-                                            4. Spatial Region
-         _Other:_ 1. Event Lists
- Spatial Region search allows for keyword search
-        examples :
-        Bow Shock to ~60 Re,     L1,       Inner Heliosphere ( < 0.8 AU )
- Mid Heliosphere ( 0.8 AU to 5 AU ),      Outer Heliosphere ( > 5 AU )
-  **Note: solar wind data only, magnetospheric data removed**

## VHO Searches

- Complex Queries:  find data when multiple conditions are true
- Find other heliospheric data sets to use along with STEREO

**Ulysses**

**STEREO Behind**

**STEREO Ahead**

**WIND**

**ACE**

***30 Nov, 2007***

## Spectrum of Users

**Web Based Interface**

**Public Tools      **
** ****CoSEC, ACE Science Center**

**Application Programming Interface (API)**

-  Access all                 types of   searches and services from VHO web page

-  CoSEC Client software being written to access VHO

-  Access VHO from your own software

- Simplicity

- Complexity

-  Easy access
-  Fixed Interface

-  More advanced and community provided
-  Dependant on tool providers

-  Complete flexibility
-  Steep learning curve

## Services and Tools

**Services offer automated data processing:**
- Coordinate Transformations - 12 coordinate systems
- Ascii Subsetting - subset a few hours from file
-  CoSEC interface offers ability to use services outside of VHO
- Examples of how to use through API/CoSEC
- Example of how to interface with SSCWeb
- Metadata standardization for services

## STEREO Related Functionality

- Collaborating with VSO team to set up cross VO queries
- STEREO data users will not have to go to both VSO and VHO to get STEREO data
- Future Services
- Merging multi-spacecraft time series data and solar images into one file
- Backtracing to get solar images

## Summary

- Prototype available at http://vho.nasa.gov
- Encourage community input on services and methods used in services
- SW propagation methods
- Means of combining in-situ and remote data
- Encourage input regarding models and their integration into virtual observatories