Transcript Signal Strength During Early Operations

The Kepler
Data Management Center
Daryl Swade
February 19, 2009
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Outline
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Science goals
Mission design
Data capture
Ground Segment
Role of the DMC
DMC development
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Science Goals
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Science requirements
The scientific goal of the Kepler Mission is to explore the structure and diversity of
planetary systems. This is achieved by observing a large sample of dwarf (mainsequence) stars to:
1. Determine the frequency of terrestrial and larger planets in or near the habitable zone
of a wide variety of spectral types of stars;
2. Determine the distributions of size and semi-major axis of these planets;
3. Estimate the frequency and orbital distribution of planets in multiple-star systems;
4. Determine the distributions of semi-major axis, albedo, size, mass and density of
short-period giant planets;
5. Identify additional members of each photometrically discovered planetary system
using complementary techniques; and
6. Determine the properties of those stars that harbor planetary systems.
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Habitable zone
The Habitable Zone (HZ) in green is the distance from a star where liquid water is expected
to exist on the planet’s surface. (Kasting, Whitmire and Reynolds, 1993)
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Extra-solar planet detections
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Planetary transits
Jupiter:
1% area of the Sun (1/100)
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Earth or Venus
0.01% area of the Sun (1/10,000)
The relative change in brightness (DL / L) is equal to the relative areas (Aplanet/Astar)
To measure 0.01% must get above the Earth’s atmosphere
Requires at least 3 transits preferably 4 with same brightness change, duration (how
long the star is dimmer), and period (time between dimmings)
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Transit detection simulations
The strong minimum at 365 days in
blue indicates the presence of a planet
with a high confidence level. The red
points are the result for the same data
set without transits, with all events
attributable to noise.
February 19, 2009
The four sections of a light curve
containing the transits of an Earth-size
planet (1.0 Re) are folded at the
correct period, with the sum shown in
red. The presence of the transit is
unmistakable.
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Follow-on program
STIS observations of HD 209458
Credits: NASA, T.M. Brown, D. Charbonneau, R.L. Gilliland, R.W. Noyes, & A. Burrows .
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Geometry for transit probability
→ need to observe a large number of stars to get a significant number of transits
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Kepler field of view
Kepler will simultaneously monitor
100,000 - 170,000 targets with data points
at a cadence of 30 minutes. 512 target stars
will also be monitored every minute.
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Expected results
Hypothesis: all dwarf stars have planets and monitor 100,000 dwarf stars for 4 years
Transits of terrestrial planets:
About 50 planets if most have R~1.0 R (M~1.0 M )
About 185 planets if most have R~1.3 R (M~2.2 M )
About 640 planets if most have R ~2.2 R (M~10 M )
About 70 cases (12%) of 2 or more planets per system
Transits of thousands of terrestrial planets:
If most have orbits much less than 1 AU
Modulation of reflected light of giant inner planets:
About 870 planets with periods ≤1 week, 35 with transits
Albedos for 100 giants planets also seen in transit
Transits of giant planets:
About 135 inner-orbit planet detections
Densities for about 35 giants planets from radial velocity data
About 30 outer-orbit planet detections
Results expected will most likely be a mix of the above
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Mission Design
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Kepler spacecraft
Sun Shade
CCD Radiator
Photometer
Solar Panel
Star Trackers
HGA
KCBs
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Kepler photometer
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Kepler mirror
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CCD detectors
The Kepler focal plane consists
of 42 science CCD and 4 fine
guidance CCD. Each science
CCD is 2200 columns by 1024
rows, thinned, back-illuminated,
anti-reflection coated, 4-phase
devices manufactured by e2v.
Each CCD has two outputs with
the serial channel on the long
edge. The pixels are 27 m
square, corresponding to 3.98
arcsec on the sky.
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Detector layout
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Launch
Delta II 7925-10L
March 5, 2009 10:48:43 pm EST
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Kepler orbit
Earth-trailing solar orbit provides thermal stability and continuous viewing.
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Commissioning
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Duration: 45-60 days
Activities
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De-spin and establish pointing control, turn on star trackers
Determine orbit with 2-way Doppler X-band radiometric data
Initialize photometer (day 2-4) – first FFIs to DMC
Ka band checkout and calibration
Gather data on distribution of cosmic rays (day 11)
Obtain CCD bias, dark, and hot-pixels (day 13)
Dust cover ejection – first light FFI (day 20)
Calibrate Fine Guidance Sensors; achieve Fine Point guidance (day 24)
Determine encircled energy (days 27-30)
Adjust to final focus with reference pixels (day 30)
Map focal plane geometry; FGS to focal plane alignment (day 31)
Measure stellar variability; FFI every four hours for six days
Measure scattered light and ghosting from bright targets (days 31 and 32)
Characterize Pixel Response Function (days 35-38)
Characterize photometer gain and linearity (day 39)
Determine noise level for target stars (preliminary CDPP) (days 40-47)
Update target definitions for science
Configure for science operations (day 50)
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Mission Timeline
Terminal
Countdown
(L – 2 hours)
Launch
L + 60 days
Launch Vehicle
Separation
(L + 55 min)
Launch
Phase
Launch & Early
Ops Period
Official Mission
Phase Definitions
Auto-init start*
Power
positive*
Uplink
confirmed
Commissioning
Phase
L + 3.5 years
1 year
Science Operations
Phase
Early Sci
Fine Pt
Ops Period
& Focus
Eject
Cover*
Photometer
Photo Act &
characterization
Dark c/o
Start
complete (L+60d)
Science
KaData collection
c/o Remaining
Photometer
S/S
Observing (Planet Find)
Characterization:
Act
+Pixel Response Function
& c/o +Focal Plane Geometry
4day contacts
Extended
Mission 
Post Ops
Phase
“Decommissioning”
Completion of
final data
analysis
30 day contacts
Quarterly rolls
Data Analysis (Incremental)
Data Analysis (final)
Follow-up Observing (summer observing seasons)
What’s Really
Happening
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*Dust Cover Ejection (DCE) planned for L+19 days
but can be extended indefinitely if required
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Data Collection
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Kepler star field
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Kepler Stellar Classification Program
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Developed Kepler Input Catalog (KIC)
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Results of multi-band ground-based photometry and spectroscopy
Used to select optimum targets for Kepler mission
Team led by Dave Latham at the Smithsonian Astrophysical Observatory
Photometry obtained with CCD cameras at the 48-inch telescope at Fred
Lawrence Whipple Observatory (FLWO) located on Mount Hopkins in Arizona
Includes ~13 million stars in Kepler field-of-view
– KIC-10 has 13,161,029 rows
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Photometry of ~2 million stars to K ~14.5 mag
High-resolution spectra for samples of promising candidates for planetary
target stars obtained with the MMT multi-fiber CCD echelle spectrograph.
Determined astrophysical characteristics
– Each object assigned a unique Kepler ID
– Observed quantities: position, proper motion, apparent magnitude (SDSS u, g, r,
i, z; SAO D51, Gred; 2MASS J, H, K, Kepler passband), galaxy, blend, variability
– Derived quantities: Teff, log(g), [Fe/H], reddening, mass, radius, extinction
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Target selection
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Long cadence targets
– 100,000 -170,000 targets with an average of 32 pixels per target
– ~ 30 minutes accumulation per cadence (~6 seconds per readout)
– Change quarterly
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Short cadence targets
– 512 targets with an average of 85 pixels per target
– ~ 1 minute accumulation per cadence (~6 seconds per readout)
– Change monthly, uplinked quarterly
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Long cadence background pixels
– 4500 pixels per module/output
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Long cadence collateral pixels
– Black-level, masked, virtual smear - used to measure black-level and smear and
to calculate dark current
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Short cadence collateral pixels
– Black-level, masked, virtual smear, black-masked, black-virtual
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GO program: 5000 long cadence targets, 25 short cadence targets per
quarter
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Target pixel read-out
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Each target assigned one of 1024 apertures
Background targets also assigned to one of 1024 different apertures
Only ~ 5% of pixels written to SSR
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Pixel types in module/output
covered with
aluminum to allow
for an estimate of the
dark and the smear
charge
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Short cadence collateral selection
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On-board compression
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Even with selective capture of pixels, data volume still too high for SSR and
downlink
Requantization
– To control the quantization noise to no more than 1/4 of the intrinsic
measurement uncertainty
– Non-linear: step sizes between allowed pixel values increase as the pixel value
increases
– Reduces pixel depth from 23 bits to 16 bits
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Baseline
– No further compression on every 48th long cadence, 1440th short cadence
– Difference with next 48 requantized long cadences , 1440 short cadences
– Includes previous next baseline → residual baseline
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Huffman Encoding
– Huffman encoding of differenced cadences reduces average bits per pixel to ~5
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Data downlink
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ORR estimate of SSR capacity: ~57 days
Monthly Ka band downlink
– Kepler is the first mission to use Ka band services of DSN
– Ka band provides higher data transmission rates at a cost of increased dropouts due to atmospheric water vapor
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Procedural retransmission strategy provides redundancy
KCB
SSR
KCB
VCDU
Source packet(s)
Bits
Source packet(s)
Source packet(s)
CB
CB
CB
CB
...
DMC
MOC
Source packet(s)
Bits
CB
CB
VCDU
Source packet(s)
CB
Data Completeness
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Ground Segment
Key
Project
Scheduling
Services
Navigation (NAV)
JPL
Deep Space
Mission Systems
Mission
Operations Center
LASP
Data Management
Center
STScI
Functional Interface
Primary Command Flow
Primary Telemetry Flow
February 19, 2009
Flight Planning
Center
BATC
JPL
ARC
BATC
LASP
STScI
Sci Team
Mission
Management
Office
ARC
Science
Operations Center
ARC
Science Office
ARC
Stellar
Classification
Program
Follow-up
Observing
Program
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Data Management Center
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DMC functional overview
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Science data processing
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Uncompress science telemetry
Convert science telemetry into FITS format files
Extract ancillary engineering data to FITS format files
Convert s/c clock to UTC
Determine World Coordinate System parameters
Correct for velocity aberration
Correct to Barycentric time
FFI Calibration
– Calibrate FFI data to remove pixel level systematic errors
– Remove bias (black-level), smear, and dark-current with collateral data
– Apply pixel corrections from Focal Plane Characterization Models
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Science data archive
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Ingest and save data
Maintain archive catalog
Distribute data distribution under proprietary rights
Provide archive user interface
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DMC functional block diagram
MOC
Data Users
science (level 1a) telemetry
gap reports
ancillary engineering data
s/c ephemeris
time correlation coefficients
data collection timeline
s/c configuration map
archive products
DMC
Level 1
processing
Kepler Data
Archive
original (level 1b) FITS data set
pixel mapping reference files
MAST
FFI calibration /
level 2 processing
original (level 1b) FITS data sets
calibrated FFI FITS data sets
pixel mapping reference files
gap reports
target definitions
aperture definitions
compression tables
calibrated (level 2) cadence data
calibrated light curves
focal plane characterization model files
Kepler input catalog
characteristics table
Kepler target catalog
Kepler results catalog
SOC
Target and
aperture definitions
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Cadence
calibration / level 2
processing
Data Analysis
Level 3 processing
Catalog
Generation
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FFI calibration algorithm
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Data products
Data Products
Data File Organization
Source
Long Cadence Science Data
Target, collateral, background
DMC, SOC
Short Cadence Science Data
Target, collateral
DMC, SOC
Ancillary Engineering Data
Cadence
DMC
Full Frame Images
Original, calibrated
DMC
Pixel Mapping Reference Files
Target, collateral, background
DMC
Target Pixel Data
Target, collateral, background
DMC
Calibrated Light Curves
Target
SOC
Focal Plane Characteristic Models
Focal plane image or model
SO/SOC
The DMC will also stage four SOC catalogs for query by archive users:
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Kepler Input Catalog
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Characteristics Table
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Kepler Target Catalog
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Kepler Results Catalog
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DMC data volume estimates
Monthly pipeline processing
Type of Data
Data rate
Compressed photometer data from MOC to DMC
7.0 GBytes / month
Original data generated at DMC
105 GBytes / month
Archive
Product
Source
Rate
Science telemetry
MOC
7.0 GB/month
0.5 TB
Calibrated cadence data
DMC & SOC
567 GB/quarter
13.3 TB
Target pixel data
DMC
567 GB/quarter
13.3 TB
Light curve data
SOC
235 GB/quarter
5.5 TB
Total
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Total size for 6 year mission
(uncompressed, unmirrored)
32.6 TB
Assumes 170,000 targets for entire mission
FFI: 389 MB each, total archive size < 50 GB for ~100 FFIs over mission
Other data types archive volume very small in comparison: ancillary engineering, s/c ephemeris, pixel
mapping reference files, gap reports, …
Factor of 2 gzip compression anticipated when writing to storage media (not include in above table)
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Kepler search forms
search by
target
search by
position
search by
Kepler ID
sort output
specify output
format
list output
columns
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DMC Development
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Verification & validation process
Science
requirements
Operations
concept
DMC
procedures
Mission
requirements
Ground
segment
architecture
DMC
architecture
DMC design
documents
and ICDs
Ground segment
requirements
Ground
system test
reports
Ground system
tests
DMC
requirements
DMC OIAs
Archive
user’s guide
Build test
reports
Build tests
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Verified requirements
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Software
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February 19, 2009
ORR test
reports
Operational
readiness tests
Used DOORS to track
requirements and architecture
Validated data products
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DMC development summary (1/2)
DMC
build
Functionality
Delivered
to test
Released
Supported tests
K0
Initial data processing pipeline: read science telemetry,
uncompress data, FITS format
N/A
(prototype)
8/29/2005
Demonstration for
DMC iCDR
K1
Production data processing pipeline, initial MOC and SOC
interfaces, FITS header keyword updates, cadence calibration,
cosmic ray rejection table, PMRFs
5/31/2006
8/14/2006
K2
Pipeline and calibration updates, archive ingest and catalog,
safestore, FITS header keyword updates
9/18/2006
12/22/2006
K3
FITS header keyword updates, target pixel data generation,
SPICE kernel: s/c ephemeris, UTC time correlation, calibration
updates, initial archive interface
1/22/2007
4/23/2007
GSIT-1
K4
Telemetry processing updates, compression histogram,
ancillary engineering processing, pipeline enhancements, FFI
calibration updates, data distribution, archive interface updates
5/14/2007
8/6/2007
GSIT-2
K4a
Migration to Solaris 10 on SunFire 15K
8/1/2007
8/17/2007
K4b
Ephemeris processing update, DCT, notification message
enhancements, s/c config map, FITS header keyword updates
8/17/2007
9/24/2007
GSIT-3
K4c
Proprietary rights, gap processing, SCB file names, short
cadence collateral duplicate pixels
12/10/2007
1/9/2008
GSIT-4
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DMC development summary (2/2)
DMC
build
Functionality highlights
Delivered
to test
Released
Supported
tests/events
K5a
Dropped target list, Barycentric time correction, further gap
processing, cadence timing fix, FITS header keyword updates,
distribution enhancements, archive interface updates
3/3/2008
4/14/2008
GSIT-3 rerun,
EEIS-1
K5b
Tool to recreate baseline, completeness reporting,
target/aperture definition receipt updates, ancillary engineering
updates, FITS header keyword updates, WCS geometry
update
5/28/2008
6/23/2008
GSIT-5a
K6a
Archive ingest updates, requantization replan, FFI priority
processing, cadence counting fixes, GSIT-5a fixes
8/11/2008
8/25/2008
ORT-1, GSIT-5a’,
ORT-2a, EEIS-2
K6b
Target pixel generation updates, leap second handling, FITS
header keyword updates, event messages, FFI calibration
updates
10/21/2008
12/1/2008
ORT-3
K6c
PMRF/TARA fix, header keyword updates
1/12/2009
1/15/2009
EEIS-3, GSIT-5b,
ORT-4a
K7
Improved DCT handling, more automated pipeline cleanup,
light curve header updates for VO compliance
2/10/2009
TBD
Phase E
operations
K8
GO information handling, target pixel generation efficiency
4/7/2009
TBD
First quarterly
SOC data delivery
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DMC hardware diagram
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7
6
5
4
3
2
1
H
H
KEPLER Data Management Systems
kepler-dms
v 1.0
Change Approval: Kepler Lead, ITSD Lead
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DEVELOPER
KEPLEROPS-DBO
SOC
SOC
MOC
MOC
03 Dec 08
page 1 of 1
G
Archive User
Operator
TUFNEL
Sun Fire 15K
8/32GB
Solaris 10
F
Data Receipt
JAWS
Sun Blade 2000
900MHz/1GB
Solaris 10
KEPTESTAA
Plasmon AA32
ArchiveAppliance
2 UDO Drives
SDP
Ingest
KEPLERIAT
Sun Fire 15K
KEPLER-OPS
Sun Fire 15K
STDATU
Sun V40z
Solaris 10
Solaris 10
RHEL4 (2.6.9)
Data Receipt
Apache 1.3.29
Web Server
Data Receipt
Test Engineer
KEPXFER
Dell Precision 450
SDP
Covalent
Enterprise
FTP Server
Ingest
Ingest
RHEL 5
Web Server
Distribution
Max Capacity
720GB
OTFR
FASTCopy
SOC USB Drive
Request data
(Starview/MAST)
Distribution
Distribution
ROBBIE
Sun Fire 15K
E
Registration
Web Application
SOC
Solaris 10
dadsdev DB
ARCHDEV
Sun V40z
opusdev DB
RHEL4 (2.6.9)
Solaris 10
keyworddev DB
Apache 1.3.29
Web Server
dadops DB
opustst DB
E
KEPOPSAA
Plasmon AA32
ArchiveAppliance
2 UDO Drives
CATLOG
Sun Fire 15K
dadstst DB
D
F
SDP
Max Capacity
720GB
opusops DB
Covalent
Enterprise
FTP Server
D
keywordops DB
keywordtst DB
Request data
(Starview/MAST)
Kepler DBO
Registration
Web Application
C
TYGRA
Ultra 2
Participating
Missions
JAGA
Ultra 10
Solaris 10
Solaris 10
dadsops DB
Tomcat 4.1.27
opusops DB
Request Monitor
C
keywordops DB
Solaris 8
KEPLER
B
ZEPPO
Sun Fire 15K
HST
Tomcat 4.1.27
KEPLER-SAN
EMC CX700
Request Monitor
2 TB dev
B
2 TB I&T
MAST
8 TB ops
35TB capacity
DEVELOPMENT
INTEGRATION & TEST
OPERATIONS
A
A
8
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6
5
4
3
2
1
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DMC network diagram
LASP
ARC
MOC
SOC
Internet
NISN
NASA PIP
STScI
MAST interface
GSFC
STScI network
HSTnet
DMC
Kepler data
archive
SunFire 15K
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DMC operations overview
DMC
Operations
week
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
Receive Target
and Aperture
Definitions
Process Science
Data
Archive science
and ancillary
engineering
telemetry
Transfer
Cadence Data fo
SOC
SOC quarterly
processing
Receive fully
calibrated
cadence data
and calibrated
light
curves
Archive
fullyfrom
calibrated
cadence data
and calibrated
light curves
Generate
target
pixel data
Archive target
pixel data
legend:
February 19, 2009
data taken in quarter 1
data taken in quarter 2
data taken in quarter 3
data taken in quarter 4
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Kepler DMC development team
Lynn Bogovich
Chris Boyer
Dorothy Fraquelli
Niall Gaffney
Ron Gilliland
Phil Goldstein
Dave Grumm
Forrest Hamilton
Phil Hodge
Robert Jedrzejewski
Tim Kimball
Rich Kidwell
John Scott
Myron Smith
Chris Sontag
Daryl Swade
Mike Swam
Dave Taylor
Randy Thompson
Shui-Ay Tseng
February 19, 2009
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