GLAST LAT Project
ISOC CDR, 4 August 2004
GLAST Large Area Telescope:
Gamma-ray Large
Area Space
Telescope
Instrument Science Operations Center
CDR
Section 3.3
Performance Verification and
Optimization
Eduardo do Couto e Silva
SLAC
I&T Science Verification Analysis and Calibration
Manager
eduardo@slac.stanford.edu
650-9262698
Document: LAT-PR-04500
Section 3.3
1
GLAST LAT Project
ISOC CDR, 4 August 2004
Relation between I&T and ISOC
•
The functions performed by the Science Verification Analysis and
Calibration (SVAC) Dept of the I&T subsystem form the basis for
performance verification and optimization required by the ISOC
•
There will be two main transition phases
– Phase A :
– Hardware tests will incorporate full capabilities from Flight
Software
– Up to the end of Phase A I&T and ISOC functions are almost
indistinguishable.
– Phase B :
– Preparations for on-orbit activities including optimization and
performance focusing on astronomical sources
– During Phase B: ISOC specific functions dominate
This talk addresses Phase A only
Document: LAT-PR-04500
Section 3.3
2
GLAST LAT Project
ISOC CDR, 4 August 2004
Overview of High Level Requirements
•
During LAT Integration, the I&T SVAC Department shall
– Process, archive and verify the integrity of data taken with
Cosmic rays and VDG photons
–
–
Generate calibrated data analysis files and update, improve and
track changes in the calibration constants used by the SAS
reconstruction during I&T
–
–
Types are specified in the LAT SVAC Plan (LAT-TD-00446) and
references within
Characterize Low Level Performance for Cosmic Rays and VDG
photons
–
–
Data runs are specified in the VG and CR Data Runs for LAT
Integration LAT-MD-04136
Details to appear in the LAT SVAC Plan for LAT Integration at
SLAC (LAT-TD-00575) and references within-
Validate MC simulations for Cosmic Rays and VDG photons
–
Details to appear in the LAT SVAC Plan for LAT Integration at
SLAC (LAT-TD-00575) and references within-
Document: LAT-PR-04500
Section 3.3
3
GLAST LAT Project
ISOC CDR, 4 August 2004
Overview of High Level Requirements
•
During LAT Operation the Performance Verification and
Optimization team will be responsible for:
– instrument calibration from low level through IRFs,
– continuous monitoring of the LAT science performance,
identification of instrument performance trends and
resolution of anomalies,
– generation and initial validation of algorithms that improve
on-orbit performance of the LAT,
– management of test and calibration data collected prelaunch.
– Configuration and maintenance of the LAT reference
geometry and the LAT Monte Carlo Model.
We will perform these functions by building on the tools
developed by the I&T SVAC effort.
Document: LAT-PR-04500
Section 3.3
4
GLAST LAT Project
ISOC CDR, 4 August 2004
SVAC Plan – LAT-MD-00446
•
•
The I&T SVAC Activities
– Support the verification of the LAT Science Requirements
– Are described by the L3 document, LAT SVAC Plan (LATMD-00446), which is the master plan and has been
updated in collaboration with the ISOC.
The ISOC PV&O Activities
– Are described in the Level II and Level III requirements and
follow directly from the I&T SVAC effort
Document: LAT-PR-04500
Section 3.3
5
GLAST LAT Project
ISOC CDR, 4 August 2004
SVAC Organization
Eduardo do Couto e Silva
Manager
Anders W. Borgland
Engineering Physicist
Many of the personnel will transfer to ISOC
during latter phases of I&T
Functions will most likely be expanded
Warren Focke
Engineering Physicist
Xin Chen
Software Developer
Code Management
Instrument Configuration
Calibrations and Data Reports
Geometry and Event Display
Pipeline Processing
Electronic Log and Database
Data Analysis
Data Analysis
Data Analysis
The main focus involves calibrations and data analysis using SAS software
Document: LAT-PR-04500
Section 3.3
6
GLAST LAT Project
ISOC CDR, 4 August 2004
Science Requirements Verification (1)
• Responsibilities:
– Peter Michelson, as Principal Investigator
– ensure the requirements are met
– Delegated to Steve Ritz, as Instrument Scientist.
• Requirements Verification
– First performed by analysis during I&T using the instrument
simulation
– Include estimates of the uncertainties in the results of the
analysis
– Presented at the Pre-Ship Review (PSR)
– prior to delivery to Spectrum Astro
– Continues during Observatory level integration and then
throughout on-orbit operations, particularly during early orbit
checkout
Document: LAT-PR-04500
Section 3.3
7
GLAST LAT Project
ISOC CDR, 4 August 2004
Science Requirements Verification (2)
•
Responsibilities for the analysis for the verification
– Carried out by members of the LAT collaboration
– Our team will be responsible for performing
– characterization of the low-level instrument performance
» using cosmic rays or photons after launch
– comparison of the simulation and data
» using cosmic rays and 18 MeV photons from the VDG or with
flight data after launch
– both of these items will be used to reduce the systematic errors of
the MC predictions of the analysis verifying the science requirements
prior to PSR.
– SAS
• Support analysis in the context of the Analysis Group
– Include characteristics of the real instrument in the simulation used
for the analysis.
» e.g. update estimates of the noise, non-linearities, bad channels
• Support ISOC, I&T SVAC and Instrument Analysis Group
– delivers to I&T and the ISOC a production-quality, configurationcontrolled version of the simulation and reconstruction software
Document: LAT-PR-04500
Section 3.3
8
GLAST LAT Project
ISOC CDR, 4 August 2004
MC Validation and Low Level Performance
• MC Verification and Low Level performance tasks are
intertwined
– Requirement
– Validate LAT MC simulations and low level performance
using cosmic rays and VDG photons
– Datasets
– Obtained after the LAT is assembled at nominal settings
– Results
– Presented as a form of report to LAT instrument Scientist
(LAT-TD-01595) at the end of the LAT integration
– Timescale for Results
– 8 weeks (TBR) after completion of the data taking
» Depends on complexity of tasks
» Preliminary verification will be performed for 1, 2 and
8 towers (TBR) throughout LAT integration
Document: LAT-PR-04500
Section 3.3
9
GLAST LAT Project
ISOC CDR, 4 August 2004
Overview of Activities
I&T/SVAC- ISOC/PVO
Strong dependency on SAS for the pipeline
ISOC
SAS
Pipeline
Data
Storage
Digi
ROOT
LDF
Calibration
constants
Recon
ROOT
SVAC
ROOT
Data
Analysis
merit
ROOT
Reports
Document: LAT-PR-04500
Section 3.3
10
GLAST LAT Project
ISOC CDR, 4 August 2004
Scripts for the Data Processing
Calibration
constants
Script 1
manual
LDF
Online
Snapshots
Online
report
Script 4
Digi
ROOT
Script 3
Configuration
Report
Script 2
Electronic Log
Tables
Document: LAT-PR-04500
Script 6
Script 5
Script 8
Analysis
ROOT
Script 7
Recon
Report
Recon
ROOT
Digi
Report
Preliminary
(under implementation in I&T)
1.
2.
3.
4.
5.
6.
7.
8.
Launch SVAC scripts (delivered to Online)
Parse Online report into electronic logbook (Web)
Parse schema from Online into tables (Web)
Parse LDF from Online into SAS ROOT
Create a summary digi report (E2E tests)
Create calibrated/reconstructed ROOT files
Create a summary recon report (detailed analysis)
Create Analysis ROOT files (detailed analysis)
Section 3.3
11
GLAST LAT Project
ISOC CDR, 4 August 2004
TKR calibrations (dead strips in EM1)
Tests with data from EM1 prototype
Dead strip xml file
Output Calibration data
Y3
Y2
Y1
Document: LAT-PR-04500
<uniplane tray="4" which="bot" >
<stripSpan first= "0" last= "156" />
</uniplane>
<uniplane tray="2" which="top" >
<stripList strips= " 561 1073 1445
1449 1464 1487 " />
</uniplane>
<uniplane tray="2" which="bot”>
<stripSpan first= "1151" last= "1535" />
"</uniplane>
Section 3.3
12
GLAST LAT Project
ISOC CDR, 4 August 2004
CAL Calibrations (light asymmetry in EM1)
Output Calibration data
<muSlope slope="1032.68" range="LEX8" />
Light asymmetry = Log ( ADC(pos) / ADC(neg) )
Slope is the calibrated attenuation length
Assume edges
Have the same
behavior
Final algorithm
will address
calibration at the
edges
Tests with data
from EM1 prototype
Unit length = 2.78mm
crystal
16.7 cm
33.4 cm
Document: LAT-PR-04500
Section 3.3
13
GLAST LAT Project
ISOC CDR, 4 August 2004
Trending Requirements
• Calibration constants shall be trended to monitor changes as a
function of time
– The query system shall display the results from
– the latest calibrations
– for history of all calibrations
– The query system shall have web based capabilities
– that produces plots and tables
Document: LAT-PR-04500
Section 3.3
14
GLAST LAT Project
ISOC CDR, 4 August 2004
Software infrastructure
Calibration
constants
Manual input
Web display
SAS Database provides pointers
to files which contain calibration
constants
Constants are retrieved using
SAS interface and populate
trending database
trendDb
java
Trending database is being
implemented by ISOC for
use by SVAC during I&T
SAS
Database
Document: LAT-PR-04500
populateDb
C++
Trending
Database
Section 3.3
15
GLAST LAT Project
ISOC CDR, 4 August 2004
Data Analysis Infrastructure
• Geometry description (Data and MC)
– required by the SAS reconstruction package to identify
nominal position of active and passive elements in the
instrument.
• Material description (MC)
– required by the SAS reconstruction package to simulate
physics processes as particles propagate through active
and passive elements. Useful for ISOC in anomaly
resolution.
• Event Display
– required to visualize geometry implementation and event
topology to aid during LAT data analysis
Document: LAT-PR-04500
Section 3.3
16
GLAST LAT Project
ISOC CDR, 4 August 2004
Two Tower Simulation Example
New Event Display ! (FRED)
Simulations of 1 and 2 towers in the assigned position in the grid have
already been implemented for the Instrument Workshop Analysis (June 7,8)
Document: LAT-PR-04500
Section 3.3
17
GLAST LAT Project
ISOC CDR, 4 August 2004
EM2 with Two ACD Tiles Geometry
Preliminary still debugging
2 ACD tiles !
TKR Minitower
4 xy planes
EM CAL
96 crystals
Work in progress!
Figure is rotated and tilted for graphical purposes
Document: LAT-PR-04500
Section 3.3
18
GLAST LAT Project
ISOC CDR, 4 August 2004
Data Analysis
• Every data run to be analyzed must have information available
on the web for easy access on
– Hardware configurations
– Register settings used for data taking
– Quality reports for digitized data
– Quality reports for reconstructed data
• Updates on Contents of reports
– Are being implemented as I&T exercises with Engineering
Models
– Will also occur during transitions phases between I&T and
ISOC
• The basic infrastructure required is in place for I&T and forms
the basis of the ISOC implementation
Document: LAT-PR-04500
Section 3.3
19
GLAST LAT Project
ISOC CDR, 4 August 2004
Query List of Runs via the Web
Run number
Date
Particle source
Hardware type
Hardware orientation
Document: LAT-PR-04500
Section 3.3
20
GLAST LAT Project
ISOC CDR, 4 August 2004
Configuration Report
Register Settings
Document: LAT-PR-04500
Section 3.3
21
GLAST LAT Project
ISOC CDR, 4 August 2004
Register settings
CAL FLE DAC Settings
TKR GTRC Splits
Document: LAT-PR-04500
Section 3.3
22
GLAST LAT Project
ISOC CDR, 4 August 2004
Quality Report (1)
Report file for the digi data
(automatically generated after each data run)
Document: LAT-PR-04500
Section 3.3
23
GLAST LAT Project
ISOC CDR, 4 August 2004
Qulity Report (2)
Cosmic ray data
EM2
Report file can be downloaded
in both
Postscript and pdf formats
Trigger info…
Document: LAT-PR-04500
Section 3.3
24
GLAST LAT Project
ISOC CDR, 4 August 2004
Quality Report (3)
Cosmic ray data
EM2
Hit multiplicities…
Document: LAT-PR-04500
Large number of hits events
seen in EM2 data
Immediately caught the attention
(as designed!)
Section 3.3
25