# Presentation: 514201

## GSFC

**Solar-Terrestrial Prove Science Applications****Multi Spacecraft Missions and****High Performance Computing**** **S. A. Curtisb_M. L. Rilee_a M. K. BhataS. A. BoardsenaA. Figueroa-Viñasb, M. Kaiserb aEmergent Information TechnologiesbNASA’s  Goddard Space Flight Center (GSFC)Greenbelt, MarylandTel: 301-286-4743/fax: 301-286-1634Michael.L.Rilee.1@gsfc.nasa.gov*REE Researcher Workshop**2001-0606 Pasadena, CA*

**GSFC**

## Overview

- Sun-Earth Connections Theme
- Solar Imaging Radio Array
- Synthetic Aperture Radio Astronomy
- Magnetospheric Multi Scale (2008)
- Multipoint in situ measurement
- Conclusion
- Returning raw data, or the next best thing.

**GSFC**

## Sun & Interplanetary Space

**GSFC**

- Visible

- Min

- Max

- EUV

- Scattered Visible

## Slide 4

## Slide 5

## Geospace

## Jan  Curtis

## Slide 8

## Slide 9

## Slide 10

## Heliosphere

**Heliosphere**

- http://helios.gsfc.nasa.gov/heliosph.html

## Science Sensors

-   Imagers
-   Gamma ray, X-ray, XUV, EUV, UV, Visible, Microwave, Radio
-   Neutral atoms
-   Point measurements
-   Particle spectroscopy 3D velocity distributions
-   e, H+, He+, He++, O+...
-   Plasma waves: AC Electric and magnetic field
-   DC Electric and magnetic field
-   Sounders/RADAR
-   Radio
-   Spacecraft housekeeping data
-   Position, attitude

## Multiplatform Missions in NASA’S Sun-Earth Connections

- CLUSTER II/ESAOC ORATOS

- MAGCON

## Technical Challenges for Multi Platform Missions

**Technical Challenges for ****Multi Platform Missions**

**Mission operations**
-  large numbers of spacecraft
-  limited operations resources per spacecraft
-  long intervals without ground contact
**Limited communication resources and opportunities**
**Limit data coverage or limit resolution**
-  **Methods that scale with Constellation size are required:**
**   ****Command and control & Science Management.**

## MULTI-PLATFORM

**MISSION ADVANTAGES**

- Simultaneous spatially separated observations.
- Coverage of large regions of interest.
- Separation of spatial from temporal effects.
- Measurement effects that couple conditions at multiple points.
- Large constellations needed to monitor Geospace dynamics.

## Synthetic Aperture Radio 

- Solar Interferometric Radio Array
- Astrophysical Low-Frequency Array
- Outer Heliospheric Radio Imager
- Twenty or more array elements, 40 receivers
- Easily generate 300 Gb/day
- 40 hours at 2 Mbps downlink

## Radio interferometry

**r1**

- LO

- LO

- X

- X

**r12**

**r2**

**k**

**lg**

- E(r1,t)=∑kE(k)exp [I k (X-r1)+(1,t)]
- V(r1,r2) = E*(r1,t) E(r2,t+lg/c)t
-        =∑klE*(k)E(l)
-                exp [I (l r2  - k r1)]
-              exp [I ((2,t+lg/c ) - (1,t)] t
-         =∑kE*(k)E(k) exp [I k (r2 - r1) ]
- V(r12) = ∑kE*(k)E(k) exp [I k r12]
- Idirty(k) = *const *∑ijV(rij) exp [-I k rij]

- Correlator

- Visibility

- Delay

- E(r2,t)

- “Dirty Map”

- Delay

- E(r2,t+lg/c)

## Radio Astronomical Imaging Application

## Radio Astronomical Imaging Application

- Desirable enhancements
-   Application to real data
-   Automated fringe detection and fitting
-   Implementation of self calibration
-   Study into wide angle and near-field techniques
-   Extended sources
-   Plasma wave dispersion relations

## Magnetospheric Multi Scale (MMS)

**Four - five formation flying spacecraft**
-   full complement of plasma diagnostic instruments
-   complex multi phase mission: four orbits in two years
**A step beyond current state-of-the-art**
-   evolutionary pathway towards advanced MAGCON,
-   operates more as one spacecraft
-   reduced contact with ground, as in deep space missions
**Magnetic reconnection, turbulence, particle energization**
-    full suite of high resolution plasma particle and wave instruments

**OVERVIEW**

## A Common Challenge: Downlink Availability

## A Sequence of Science Enhancementsfrom On-Board Computing

- Level Zero Processing
- Calibration, transfer functions
- Summary Statistics
- Plasma moments: density, temperature, fluxes
- High time resolution throughout orbit
- Event recognition
- Thresholds, trends,  discontinuities, features
- Data selection
- Adaptive compression

## Kessel, R. L., S.-H. Chen, J. L. Green, S. F. Fung, S. Boardsen, L. Tan, T. Eastman, J. Craven, and L. A. Frank, Evidence of high-latitude reconnection during northward IMF: Hawkeye observations, Geophys. Res. Letts., 23 5, 583-586, 1996. 

- Kessel, R. L., S.-H. Chen, J. L. Green, S. F. Fung, S. Boardsen, L. Tan, T. Eastman, J. Craven, and L. A. Frank, Evidence of high-latitude reconnection during northward IMF: Hawkeye observations, Geophys. Res. Letts., 23 5, 583-586, 1996.

## Slide 24

## Irregularly sampled velocity space

- Centroids of
- Particle Measurements

- A grid for numerical
- quadrature

## Plasma Moment Application

**  **Obtain Particle instrument flux measurements
-   Convert to Particle Phase-Space Densities
-   number ~ f(v)d3v
-   Construct or interpolate to grid
-   Patch defects in sampling
-   Least squares or SVD based model fitting
-   Assess patch
-   Numerical quadrature to find moments
-   density, flow velocity, pressure tensor, heat flux
-   xj x f(**v**j) d3vj
-   Assess moments for validity
-   Spacecraft potential & return current effects
-   Calibration
-   Assess moments for Science

## Science Enhancements to 

_**Science Enhancements to **_
_**Magnetospheric Multi Scale (MMS)**_

- REE/MMS: _[Steven.A.Curtis@gsfc.nasa.gov](mailto:Steven.A.Curtis@gsfc.nasa.gov)__, __[Michael.L.Rilee@gsfc.nasa.gov](mailto:Michael.L.Rilee@gsfc.nasa.gov)__ (MLR 2001-0411-1)_

## Plasma Moment Application

- Desirable enhancements
-   handling bad data
-   sun pulses
-   radiation belt contamination
-   data dropouts
-   interference and noise
-   improved low-velocity modelling
-   spacecraft potential effects
-   return currents
-   comparison with plasma wave data

## Conclusion: Results

-   Two applications modelling important space science techniques
-   Radio Astronomical Imaging
-   Plasma Moments Analysis
-   Speedup and scalability good for appropriate data sets
-   Starting to perform automated analyses of archived data
-   region/boundary identification
-   science event detection
-   feature recognition
-   Library usage
-   MPI, PLAPACK, LAPACK, FFTs, GEOMPACK...
-   Note: most scientists use RSI’s IDL or MATLAB for analysis
-   Fault sensitivity testing on PMA
-   ~80% No detectable corruption
-   ~90% Acceptable results
-   ~  8% Crash/Hang
-   ~  2% Detectably bad results

## Conclusion: Challenges

-   Reliable level-zero processing
-   instrumental effects, iterative corrections
-   High quality operational functions
-   DC Magnetometer data
-   Housekeeping data:  solar array power, thermal, sensor modes
-   Data assessment (extension of  REE data verifier)
-   low/high priority data
-   feature recognition
-   particle distribution functions
-   EM Wave data
-   intercomparison of data from different instruments
-   drives data processing: reduction vs. compression
-   On board software must be extensible
-   adjust for improvements to our understanding of the sensors