Cospar

The new code for ESA meteoroid model.

Alexey Mints1 Valery Dikarev1 Gerhard Drolshagen2

1University of Bielefeld, Germany

2European Space Agency, Noordwijk, The Netherlands

18.07.2010

Problem

Outline

1 Problem

2 Code

3 GUI

A. Mints, 18.07.2010 The new code for ESA meteoroid model. 2 / 22

Problem

Requirements

Input: Target trajectory and geometry, output contentspecification;

Output: Estimated dust flux, number density and averagevelocity. Dust distributions in mass, incidencedirection and velocity.

GUI: A tool to set input parameters and view output.


Problem

Orbital elements


Problem

Model (as of now)

5 populations, for each:

• Rectangular 3D grid in orbital space. Dimensions:pericenter distance (0.05-6 a.u., 50 log-scale bins),eccentricity (0-1, 100 bins) and inclination (0-180, 180bins);

• Mass spectra (200 log-scale bins from 10−18 to 105

grams), independent of orbital elements;

Current model file size ∼28 Mbytes.


Problem

Grids

Figure: Possible grids: regular (left), irregular (right)

Old IMEMRegular (orthogonal) grid inorbital elements.

New IMEMRegular (spherical) grid inincidence velocity.


Problem

Old and new approaches

Old IMEM

/ Jacobian diverges, tricks areneeded;

/ Incidence direction has to becalculated: have to run overthe whole model range;

, Symmetries can be used;

New IMEM

/ Symmetries cannot be used;

, No Jacobian needed;

, Incidence direction emergesnaturally from the grid;

, Reduced calculations forsensitivity;

, Various scans can be easilyimplemented;


Problem

Thresholds

C1 < mαV β < C2

• α = 1; β = 0 — mass threshold;

• α = 1; β = 1 — momentum threshold;

• α = 1; β = 2 — kinetic energy threshold;


Problem

Calculation grid

V ∗dust = V grid

dust + V ∗target

Geometrical sensitivity can be calculated from ϕ;Knowing V grid

dust we can calculate mass densities as∫ C2/V β

C1/V β mα dm;


Code

Outline

1 Problem

2 Code

3 GUI


Code

Application layout

Java Fortran

Model

CoreI/O routines

Data module

Inputdatafiles

Outputdatafiles

Task data

Globalsettings

Resultsdata

Interface

Userdata


Code

Application composition

• Calculation engine — FORTRAN-95 program (∼4000lines);

• GUI — Java graphical interface (∼11000 lines) developed

with NetBeans ;

• User documentation;

• Model file;

• Sample task and trajectory files;


Code

Engine input files

• Task file — over 30 parameters, defining task propertiesand output content and format;

• Trajectory file — contains orbital parameters orpoint-by-point trajectory;

• Sensitivity file — optional file containing sensitivityfunction;

• Model file — dust orbital distribution model (binary file);


Code

Task file

De s c r i p t i o n=Popu l a t i o n s=∗Meteoro id mode l=T r a j e c t o r y f i l e=x . t r jS e n s i t i v i t y f i l e=t . t s k s e n sP l o t s e t t i n g s=t . t s k p l o tRe s u l t=t . t s k r e sS e n s i t i v i t y p r e s e t =0P o p u l a t i o n s s t y l e=1P o i n t s s t y l e=1C o o r d i n a t e s s t y l e=1Ea r t h c o o r d i n a t e s=0Scan mode=0Phy s un i t s=0F lux=1Number dens i ty=0A v e r a g e v e l o c i t y=1Thre sho l d s=m, 1 .00 e−18, 1 .00 e+02I n c i d e n c e r a n g e =0.00 :180 .000000V e l o c i t y r a n g e =0.000000:100000.000000Ta rge t t yp e=0Ta r g e t o r i e n t a t i o n=0O r b i t k i n d=1O r b i t s o l a r=0O r b i t e c l i p t i c a l =0


Code

Engine output

#IMEM2 output f i l e#Created=20/ 5/2010 20 : 2 7 : 3 5 . 1 60#Phy s un i t s=F#Scan mode=0#S c a n r e s o l u t i o n= 20#P o p u l a t i o n s s t y l e=1#P o i n t s s t y l e=1#Th r e s h o l d s i n c o l umn s=F#C o o r d i n a t e s s t y l e=1#Ea r t h c o o r d i n a t e s=F#Number dens i ty=F#Flux=T#Av e r a g e v e l o c i t y=T#Targe t t yp e=0#Ta r g e t o r i e n t a t i o n=0#S e n s i t i v i t y p r e s e t =0#T r a j e c t o r y t y p e=0#T r a j e c t o r y t y p e= 0 . : 180 .#M i s s i o n d u r a t i o n= 3 .0#Mi s s i o n l a un ch= 0 .0#Po in t Thr | Time | a s t e r o i d s c o l l i s i o n s | . . .# | | F lux | AvgV | . . .# 1 | 2 | 3 | 4 | 5 | . . .

1 1 0.00000000E+00 0.0000000E+000 0.0000000E+000 . . .2 1 0.10000000E+01 0.0000000E+000 0.0000000E+000 . . .3 1 0.20000000E+01 0.0000000E+000 0.0000000E+000 . . .4 1 0.30000000E+01 0.0000000E+000 0.0000000E+000 . . .. . . .. . . .A. Mints, 18.07.2010 The new code for ESA meteoroid model. 15 / 22

GUI

Outline

1 Problem

2 Code

3 GUI


GUI

Main window


GUI

Output properties window


GUI

Progress window


GUI

Plots


GUI

Maps


GUI

Future plans

• Final release – September 2010;

• OpenMP and MPI extensions;

• Web-interface;

• More Engine features (for example, meteor flux for agiven location on Earth);


Date post:	17-Aug-2015
Category:	Technology
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Cospar

Technology