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

www.DLR.de • Folie 2

Precise orbit information of (all) objects required

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

www.DLR.de • Folie 3

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

www.DLR.de • Folie 4

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

Ø20cm, 2.0° FOV, 1.8“/Pixel

• Sutherland Observatory, South Africa

Motivation: Operational Collision Avoidance in GEO

www.DLR.de • Folie 5

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

Ø20cm, 2.0° FOV, 1.8“/Pixel

• Sutherland Observatory, South Africa

Motivation: Operational Collision Avoidance in GEO

www.DLR.de • Folie 6

Sutherland

Zimmerwald ---- Sunset

Sunrise

Integrated Obs-Time:

Average > 11.5h!

Motivation: Operational Collision Avoidance in GEO

www.DLR.de • Folie 7

Coverage: - 32% of geostationary ring

- 61% of active satellites

Coverage: - 83% of geostationary ring

- 89% of active satellites

Coverage: - 100% of geostationary ring

- 100% 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

www.DLR.de • Folie 8

Object Identification with Optical Measurements

Least squares fit

New measurement type:

Attributable

www.DLR.de • Folie 9

Loss function L

Optimisation Lambert-Solution

www.DLR.de • Folie 10

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

www.DLR.de • Folie 11

Maximum

161m

84m

78m

74m

71m

64m

www.DLR.de • Folie 12

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

www.DLR.de • Folie 13

• 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

www.DLR.de • Folie 14

What is BACARDI?

BACARDI

Backbone Catalogue of Relational

Debris Information

Visit of Paul Cefola, / 09. October 2012

www.DLR.de • Folie 15

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

www.DLR.de • Folie 16

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

www.DLR.de • Folie 17

(provenance data)

BACARDI: Internal Nodes

www.DLR.de • Folie 18

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

www.DLR.de • Folie 19

Conclusions

www.DLR.de • Folie 20

• 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

www.DLR.de • Folie 21

Thanks for Your Attention!

Re-Entry Predictions 2012