Space Situational Awareness Forum - GERMAN AEROSPACE CENTRE Presentation

SMARTnet –Results of Test

Campaigns

Hauke Fiedler, Thomas Schildknecht, Martin Weigel, Michael

Meinel, Rolf Hempel, Johannes Herzog, Marcel Prohaska, Martin

Ploner, Jan Siminski

www.DLR.de • Folie 1

Processed Conjunctions

2012 2013 2014

Satellite Altitude CSM CAM CSM CAM CSM/CDM CAM

TSX/TDX

(excl.tdtx)

510 16 2 2222

(1560)

0 7366

(4237)

4

GRACE-1 460 (-400) 1 0 0 0 0 0

GRACE-2 460 (-400) 1 0 2 0 0 0

BIR 510 (-480) 8 0 0 0 10 0

TET 500 (-460) 3 0 1 0 0 0

SBW-1

(excl.ctrl)

GEO 35

(6)

1 19

(6)

0 110

(8)

0

SBW-2

(excl.ctrl)

GEO 59

(0)

0 135

(2)

0 224

(6)

0

- CSM generation thresholds for TSX/TDX were enlarged August 2013

- Message format was changed to CDM in May 2014


Precise orbit information of (all) objects required

Sensors for: LEO (expansive) – GEO (not so expansive)


10.02.2009 Motivation: Operational Collision Avoidance at GSOC

TerraSAR-X (2007-) / TanDEM-X (2010-)

- Controlled against a reference orbit inside a tube of 250 m radius

- Flying in a close formation with the relative distance < 500 m

- 510 km altitude

Conjunction on 2014/03/03

SMARTnet

Optical Network for Monitoring

Geostationary Orbits


Global network for monitoring the geostationary ring

• Theory: complete coverage with 3 locations

• Northern / southern hemisphere for compensating

seasonal variations 6 locations

• Telerobotical operation

• Close cooperation with AIUB / ZIMsmart-telescope

• Optimized scheduler for all telescopes

SMART-01:

• Mounting with 2 telescopes

Ø50cm, 0.7° FOV, 0.6“/Pixel


• Sutherland Observatory, South Africa

Motivation: Operational Collision Avoidance in GEO


Global network for monitoring the geostationary ring

• Theory: complete coverage with 3 locations

• Northern / southern hemisphere for compensating

seasonal variations 6 locations

• Telerobotical operation

• Close cooperation with AIUB / ZIMsmart-telescope

• Optimized scheduler for all telescopes

SMART-01:

• Mounting with 2 telescopes



• Sutherland Observatory, South Africa



Sutherland

Zimmerwald ---- Sunset

Sunrise

Integrated Obs-Time:

Average > 11.5h!



Coverage: - 32% of geostationary ring

- 61% of active satellites





Status

• Mounting, 50cm telescope

and CCD camera tested

• Serveral nights

• Objects down to 18.5mag

detected

• First 2 nights:

• Long test run: May – June

o 46 COSPAR Objects

o 14 AIUB Objects

o 10 unknown objects

Geostationary object

Tracklet: Epoch + RA / DEC from image

SMARTnet: Test Campaign at Zimmerwald


Object Identification with Optical Measurements

Least squares fit

New measurement type:

Attributable


Loss function L

Optimisation Lambert-Solution


Object Identification with Optical Measurements

• Separation of real / false tracklets above threshold of loss function (chi-

squared distribution)

• Filter rate depends on accuracy, time difference, survey strategy, …

Object Correlation


Maximum

161m

84m

78m

74m

71m

64m


Residuals to GPS Reference Orbit

New focusser, telescope fully collimated

Improvement: schedule observations for orbit refinement

Results: GEO Cluster (Eutelsat Hotbird 13B, 13C, 13D)

• 111 Tracklets of two nights

(Sep. 25/26, 26/27)

• TLE orbits lead to erroneous

correlation (06032A?)

• Iterative process: correlation,

orbit determination,

correlation…

• Residuals orbit determination

06032A RMS α=0.25“ δ=0.35“

08065A RMS α=0.30“ δ=0.34“

09008B RMS α=0.29“ δ=0.34“

• Final solution after 3rd iteration

with correlation of all tracklets


• Hardware and software components are tested

o Astrometric accuracy better than expected

o Limiting magnitude of telescope estimated

o Detection of unknown objects

o Identification of known objects

o Orbit determination with very small deviation to reference orbit

• Foundations in South Africa are planned this month

• Final end-to-test in Zimmerwald / Switzerland: Scheduling,

observing, pre-processing, transferring data to GSOC, cataloguing

at GSOC with BACARDI in autonomous mode

• Start of operations: end of 2015

Results


What is BACARDI?

BACARDI

Backbone Catalogue of Relational

Debris Information

Visit of Paul Cefola, / 09. October 2012


Science and Research

• Data bank of up to 1.000.000 objects

• HPC for object correlation, orbit determination,

propagation, object identification and detection

of manoeuvres and fragmentations

Mission Support

• Orbit information, collision prediction, re-entry prediction

Objective

• Data bank with preferably high completeness

and high accuracy

• Primary source: sensor data and operator data

• Secondary source: externally generated

ephemerides

BACARDI: Backbone Catalogue of Relational Debris

Information


Network of sensors

Prozessors

Interfaces

Tracking Radar Surveillance Radar Laser Tracking Telescopes Space Based

External Data

Orbit information Object properties User Sensor scheduler Solar activity

Data bank

• Sensor data

• Correlation

• Catalogue objects and candidates

• Ephemerides incl. covariance

• Maneuver planned / executed

• Meta- and log data

• Data policy

• Object correlation

• Orbit determination

• Orbit propagation

• Maneuver detection

• Fragmentation detection

• Prediction of collisions

• Re-Entry prediction

BACARDI

BACARDI Overview


(provenance data)

BACARDI: Internal Nodes


Sensor Organisation

Observation

Observation Error

Correction of Observations

Sensor Error Statistic

Object

TLE

Osculating

Elements

Ephemeris

DSST

Orbit

TLE Error Statistic

Manoeuvre

Satellite Launch

Fragmentation

Re-Entry

CA (Close

Approach)

Orbit Propagation

Orbit Modelling

Space Weather

Time & Coordinate

System

Orbit Determination

CA Analysis /

Warning

CA Detection

CA Threshold

Correlation

Features

• Definable roles for each user

• Each individual datum might has its own data policy

• Possibility of a distributed system

• Data Provenance: Provenance is information about entities, activities,

and people involved in producing a piece of data or thing, which can

be used to form assessments about its quality, reliability or

trustworthiness.

o Backtracking of each produced product (ephemerides, state

vectors, correlated objects, …)

o Reproducibility of products and data generated

BACARDI


Conclusions


• Collision analyses cost manpower, maneuver costs mission

time

• Precise orbit information essential (ephemeris - including

covariance - is required, no knowledge of object necessary)

• No information of all objects with sufficient accuracy

publically available

• Desirable: information about satellite status, post mission

disposal in GEO, and maneuvers

• SMARTnet and BACARDI set up as a GEO surveillance

system

Suggestion: open catalogue for satellite operators

with highly accurate orbit information


Thanks for Your Attention!

Re-Entry Predictions 2012

Space Situational Awareness Forum - GERMAN AEROSPACE CENTRE Presentation

Science

Transcript of Space Situational Awareness Forum - GERMAN AEROSPACE CENTRE Presentation