Transcript Systems Engineering

Systems Engineering
Chad Fish
[email protected]
435-797-0469
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
1
SOFIE CDR October 7-8, 2004
-1
Presentation Overview
•
•
•
•
•
•
•
•
•
Key System Requirements
System Design
System Operation
Technical Resources and Error Budgets
Post-PDR System Changes
Technical Risks
Technical Coordination
Summary
Supplementary Material
– Error Budget Models
– Level 3 Requirements Compendium
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
2
SOFIE CDR October 7-8, 2004
-2
Key System Requirements
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
3
SOFIE CDR October 7-8, 2004
-3
Science Objectives
•
SOFIE will support AIM mission in study of PMCs and the environment in
which they form. SOFIE will use differential solar occultation to measure:
– Five gaseous species (H2O, CO2, O3, CH4, NO)
– Temperature
– Particle extinction at 10 wavelengths
SOFIE Channel Overview
•
Channel
1
2
3
4
5
6
7
8
Target Absorber
O3
particles
H2O
CO2
particles
CH4
CO2
NO
Center  (m)
Strong band
Weak band
0.290
0.328
0.862
1.031
2.60
2.45
2.77
2.94
3.06
3.19
3.37
3.51
4.25
4.63
5.32
4.98
Each SOFIE channel uses two detectors to make three measurements:
– Strong band absorption
– Weak band absorption
– Difference signal (weak band – strong band = ΔV)
Remove interference and reduce noise!
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
4
SOFIE CDR October 7-8, 2004
-4
System Requirements
IDENTIFIER
SHORT DESCRIPTION
REQUIREMENT
(General Operational)
SOF 289
Mission Lifetime
Function 25 months following a 1 month on-orbit
commissioning.
SOF 288
Nominal Operability
Operate 95% of the time over any 5 consecutive days
during the primary science observation season.
SOF 279
Autonomous
Operations
SOFIE shall be capable of autonomous operations for at
least 96 hours.
SOF 172
Mission Ops
SOFIE shall make 2 solar occultation measurements per
orbit, one at sunrise and one at sunset.
SOF 175
Time Stamp
The SOFIE science data time stamp shall be accurate to
within 2.5 msec relative to successive data samples
during occultation measurements.
SOF 179
Spatial Resolution
The SOFIE science data products shall have 3.0 km or
less spatial resolution in elevation.
SOF 308
Sampling Rate
The SOFIE science data channel sample rates shall be
≥ 20 Hz during an occultation measurement.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
5
SOFIE CDR October 7-8, 2004
-5
System Requirements (cont)
IDENTIFIER
SHORT DESCRIPTION
REQUIREMENT
(Observational Views)
SOF 180
Instantaneous Science
FOV
The SOFIE instantaneous science FOV shall be 6 arc
minutes horizontal and 1.8 arc minutes vertical (defined
as along the axis between Nadir and Zenith).
SOF 295
Glint FOV
The SOFIE glint FOV shall be 24 deg horizontal and 32
deg vertical.
SOF 178
FOR
The SOFIE steering mirror shall provide a field of regard
of ± 2 º elevation and ± 2 º azimuth.
(Pointing)
SOF 300
SOFIE shall point the center of its FOV to ±1 arcminute
at a fixed distance relative to the solar top edge
centerpoint and maintain this position during occultation
measurement.
The pointing position will be considered "maintained" if a
10 Hz filtering (0.1 sec running mean) of the true
pointing position varies <15 arc seconds (1 sigma) in
elevation and <1.0 arcmin (1 sigma) in azimuth.
Pointing Ability
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
6
SOFIE CDR October 7-8, 2004
-6
System Requirements (Cont)
Table 2. SOFIE spectral band specifications and channel S/N requirements.
SOF 174 :
Measurement Bands
SOF 183 :
Radiometric SNR
Band
Center 
(m)
Band Limits, m
Band Limits, cm-1
S/N*
O3 strong
0.290
0.2857 - 0.2941
34000 - 35000
1.0104
O3 weak
0.328
0.3226 – 0.3333
30000 - 31000
1.0104
particle
strong
0.862
0.8475 – 0.8772
11400 - 11800
1.0106
particle weak
1.03
1.0101 – 1.0526
9500 - 9900
1.0106
H2O weak
2.45
2.427 – 2.475
4040 - 4120
2.5104
H2O strong
2.60
2.577 – 2.632
3800 - 3880
2.5104
CO2 strong
2.77
2.740 – 2.794
3580 - 3650
3.0105
CO2 weak
2.94
2.907 – 2.967
3370 - 3440
3.0105
particle
strong
3.06
3.030 – 3.091
3235 - 3300
1.0105
particle weak
3.19
3.160 – 3.226
3100 - 3165
1.0105
CH4 strong
3.37
3.333 – 3.401
2940 - 3000
4.0105
CH4 weak
3.51
3.472 – 3.546
2820 - 2880
4.0105
CO2 strong
4.25
4.255 – 4.444
2250 - 2350
4.0105
CO2 weak
4.63
4.630 – 4.740
2110 - 2160
4.0105
NO weak
4.98
4.951 – 5.051
1980 - 2020
3.0105
NO strong
5.32
5.263 – 5.376
1860 - 1900
3.0105
*The effective noise bandwidth is 2 Hz.
Band limits are given in different units (cm-1 = 10000/m) but are otherwise identical.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
7
SOFIE CDR October 7-8, 2004
-7
System Requirements (cont)
IDENTIFIER
SHORT
DESCRIPTION
REQUIREMENT
(Solar Tracking and Maneuvering)
SOF 181
Altitude Range
SOFIE shall be able to track the top edge centerpoint
of the sun from an apparent altitude of 315 km down to
the hard edge of the Earth during an occultation
measurement.
SOF 176
Scanning
SOFIE shall provide the capability to vertically scan
across the disk of the sun four (4) times after the
sunrise occultation measurement and four (4) times
prior to the sunset occultation measurement.
SOF 304
Balancing
SOFIE shall provide the capability to balance the ΔV
signal (i.e. set Δ V to zero) using a gain setting (GA) to
within 1000 counts.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
8
SOFIE CDR October 7-8, 2004
-8
System Design
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
9
SOFIE CDR October 7-8, 2004
-9
Environmental Orbital Considerations
Orbit
- 600-650 km geocentric
- Polar sun-synchronous
- 2 year operational lifetime
Thermal Predictions
- Electronics Survival = -25 to +55 ºC
- Electronics Operation = 0 to +50 ºC
- Instrument Survival = -45 to +20 ºC
- Instrument Operation = -40 to +20 ºC
Radiation
TID = 10 kRAD
SEE = 37 MeV
Atomic Oxygen
Strongly dependent on altitude (600 km significantly less than 450 km).
Using MgF2 protective coating on our steering mirror and
primary/secondary Cassegrain telescope mirrors.
Cleanliness
Internal mirrors allowed to degrade (EOL, 26 months) to Level 500. This
includes effects of micro-meteroids.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
10 - 10
SOFIE CDR October 7-8, 2004
Design Description
•
•
Instrument Unit
– Purpose:
• Perform science signal detection & FOV pointing and stabilization control
– Contains:
• Opto-mechanics
– Mirrors, filters, beam splitters, field-stop, chopper
• [1.8’ x 6’ Inst FOV; 32º x 24º Glint FOV]
• Detector assemblies (includes TECs and PreAmps)
• Steering mirror [4º x 4º FOR]
• Sun sensor electronics and software [2º x 2º FOV]
Electronics Unit
– Purpose:
• Perform system command and control, communication, signal conditioning,
and power conditioning
– Contains:
• Command and data handling electronics and system software
• Position and stabilization control electronics and software
• Communication, signal conditioning, and mechanisms control electronics
and software
• Thermal sensor, TEC thermal control, and housekeeping electronics
• Power conditioning electronics
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
11 - 11
SOFIE CDR October 7-8, 2004
System Block Diagram
Spacecraft Deck
Instrument Unit
Steering Mirror Assembly
Pinpuller
Mechanism
Steering
Mirror
Steering Mirror
Positioning Sensor
Electronics
Solar
Input
Pinpuller
Mechanism
Sun Sensor
Pickoff Mirrors
Mechanisms
Release
Secondary
Mirror
Neutral Density Filter
Spectral (700 nm) Filter
Electronics Unit
Primary
Mirror
Cassegrain
Telescope
Sun Sensor Baffle
Mirror
Amplifier
Aperture
Cover
Field Stop
Chopper
Servo I/O
Temp Sensors /
Housekeeping
4 SWIR Bands
(2.43 - 2.97 um)
Beamsplitters
C&DH
Processor
Focal Plane
Array
Chopper
Control
4 UV,NIR Bands
(0.29 - 1.03 um)
Sun Sensor
Processor
Sun Sensor
Housing Assembly
Data Acquisition
Power Conditioning
and Distrubution
4 LWIR Bands
(4.25 - 5.32 um)
Channel Separation
Module Assembly
Individual
Band Filters
Temp
Sensors
Signal Conditioning &
TEC Control
4 SWIR Bands
(3.03 - 3.55 um)
R
a
d
i
a
t
o
r
Detector Assembly
(TEC, PreAmp)
1553 Interface
Isolator Feet (14 ° Eff Wedge)
Sensor Power,
Mechanisms Power,
and Thermal Sensors
Survival Heater Power and
Thermal Sensors
1553 Comm Bus
GATS
Spacecraft Bus
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
12 - 12
SOFIE CDR October 7-8, 2004
Spacecraft Configuration
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
13 - 13
SOFIE CDR October 7-8, 2004
Instrument Unit
Radiator
Pin pullers
Aperture cover
Steering mirror
Alignment cubes
N2 Purge
Witness Mirrors (x4)
Circular connector
interfaces
SC Isolator Feet (eff 14° wedge)
GATS
Dynamic Envelope: 16.2 x 26.3 x 29.5 inches
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
14 - 14
SOFIE CDR October 7-8, 2004
SOFIE Instrument Unit (cont)
POINTING AND
STABILIZATION CONTROL
Sun Sensor
SIGNAL DETECTION
Channel Separation Module
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
15 - 15
SOFIE CDR October 7-8, 2004
SOFIE Electronics Unit
Electronics PCBs
Top Connectors
and Cabling
SC Radiator Panel
Power Conditioning
Dynamic Envelope: 16.2 x 26.3 x 29.5 inches
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
16 - 16
SOFIE CDR October 7-8, 2004
System Operation
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
17 - 17
SOFIE CDR October 7-8, 2004
Modes of Operation
Survival
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
18 - 18
SOFIE CDR October 7-8, 2004
Modes of Operation (cont)
Mode
Measurements
Commands
Code
Updates
Survival
Heaters
Comments
Science
- Occultation
- Housekeeping
- System status
1. Real time
processed
1. Timed not
processed
Processed
ON
Standby
- Housekeeping
- System status
Real and
timed
processed
Processed
ON
Safe
- Housekeeping
- System status
Real and
timed
processed
Processed
ON
SOFIE software
can transition into
this mode without
a ground
command but
cannot transition
out without a
ground command
Survival
NA
NA
NA
ON
System power OFF
GATS
Peak data rate and
power mode
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
19 - 19
SOFIE CDR October 7-8, 2004
Science Mode
17.77 DEG
21.57 DEG
650 Km
X
473 km
315 km
24.85 DEG
SOFIE IFOV
(1.8' x 6')
LAYER HEIGHT RESOLUTION
= 25.75 m @ 0 km
= 22.52 m @ 157 km
= 18.63 m @ 315 km
158 km
Z
EARTH
SUN
SUN POINTING
Orbital Characteristics
1. 600-650 km altitude
2. Polar sun-synchronous
3. SOFIE instrument pointed by SC to within ± 1º
(3 sigma) of the solar vector during an occultation
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
20 - 20
SOFIE CDR October 7-8, 2004
Science Mode (cont)
315 km
SOFIE Max FOR
(4o x 4o)
SOFIE IFOV
(6' x 1.8')
Sun disk
(0.53o)
Sun Sensor
FOV (2o x 2o)
EARTH
Spectrum of the 16 bands
(UV)
O3
250
(NIR)
Particle
850
H 2O
1600
2350
GATS
(SWIR)
Particle
CO2
CH4
3100
nm
(MWIR)
CO2
3850
4600
NO
5350
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
21 - 21
SOFIE CDR October 7-8, 2004
Science Mode (cont)
States
General Operations
INIT
Prepare system for occultation measurements
•Synchronize electronics and software
•Initialize timing and balance commands
•Initialize tracking profiles
AQR
(15 seconds)
Search and acquire sun on FPA
•Find sun within FOR (if not found abort and return system error)
•Position sun center at center of FPA
•Begin fine tracking (arcsecond resolution) of sun
•Position IFOV at desired offset from sun center
Can overlap with DATA state
DATA
(~ 150 seconds)
•Perform science channel measurements!
•Maintain IFOV locked at desired offsets from sun center while
following table driven profile (solar tracking)
Fixed position
Solar scanning (including azimuthal offsets)
•Perform balance (set ΔV offsets) function
•Save CO2 and balance data for post occultation analysis
Can overlap with AQR state
Maximum science measurement duration (AQR, DATA) = 155 seconds
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
22 - 22
SOFIE CDR October 7-8, 2004
Science Mode (cont)
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
23 - 23
SOFIE CDR October 7-8, 2004
Conceptual Science Mode Operational Profile
Nominal Sunrise Science Occultation Measurement Profile
Timeline Duration = 155 Seconds
= 60 Seconds
FOV Maneuvers
+2 Degrees
EL and AZ
Searching
Time = TB = 170 km
Time = TFIN
Time = TA
AQR State
………….
INIT State
Time = T0.5
Time = 0
(Channel Measurements Begin)
Nominal EL Scans
Balance
Time = TL
DATA State
= 15 Seconds
Nominal Sunset Science Occultation Measurement Profile
Timeline Duration = 155 Seconds
= 60 Seconds
FOV Maneuvers
+2 Degrees
Time = TFIN
EL and AZ
Searching
Time = TB = 170 km
Time = TA
AQR State
………….
INIT State
Time = TL
Nominal EL Scans
Time = 0
(Channel Measurements Begin)
= 15 Seconds
Balance
Time = T0.5
DATA State
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
24 - 24
SOFIE CDR October 7-8, 2004
Solar Acquisition and Tracking
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
25 - 25
SOFIE CDR October 7-8, 2004
Solar Scanning and Maneuvering
Boresighting
Vertical Scanning
1 degree (3 sigma)
10 arcminutes
12 arcminutes
FOV
12 arcminutes
1 degree (3 sigma)
1 degree (3 sigma)
10 arcminutes
Scanning
1 degree (3 sigma)
Azimuthal Offsetting
(bore sighting)
Science Range
SC Pointing Accuracy Capability
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
26 - 26
SOFIE CDR October 7-8, 2004
Science Data Products
2
1. Occultation
(20 Hz)
1
-Solar edge locations (X,Y)
-Solar vertical edge and center
images
-Steering mirror command and
position (X,Y)
-All channel sets (Strong, Weak,
ΔV)
-Time stamps (SC and relative)
1
2. Diagnostic
(Limited)
-Solar images
-FPA frame images
1
El
Az
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
27 - 27
SOFIE CDR October 7-8, 2004
Commissioning Phase
WEEK 1
1. APPLY SURVIVAL HEATER POWER
2. APPLY SYSTEM POWER
3. EXERCISE BASIC COMM
*APERTURE COVER NOT RELEASED
1 MONTH
COMMISSIONING
PHASE
WEEKS 2-3
1. EXERCISE FULL COMM AND SYSTEM FUNCTIONALITY
*APERTURE COVER NOT RELEASED
WEEKS 4-5
1. RELEASE APERTURE COVER
2. PERFORM INITIAL SCIENCE AND CALIBRATION CHECKOUTS
3. VERIFY POINTING AND STABILIZATION CONTROL
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
28 - 28
SOFIE CDR October 7-8, 2004
System Technical Resources
&
Error Budgets
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
29 - 29
SOFIE CDR October 7-8, 2004
Technical Resources
RESOURCE
CURRENT BEST ESTIMATE
REQ ID
Mass
36.4 kg
SOF 194
Envelope
Controlled by MICD
SOF 195
Average Power
74.1 W
[56 W Electronics Unit, 18 W Instrument Unit]
SOF 205
Peak Power
107.6 W
SOF 206
Pinpuller Peak Power
32.2 W for < 0.5 sec,
(130 mW Pre and Post Fire)
SC ICD
Survival Heater
Average Power
15.2 W
SOF 272
Survival Heater
Peak Power
62.8 W
SOF 272
Daily Data Volume
168 Mbits/day
SOF 243
Resource margin and reserve managed by mission
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
30 - 30
SOFIE CDR October 7-8, 2004
Mass Budget
SOFIE MASS BUDGET
Instrument Unit
Part / Sub-Assembly
Steering Mirror Assembly
Feedback Sensor Module
External Cables and Connectors
Electronics Unit
Producer
Vendor
Vendor
Vendor
Mass (kg)
0.76
0.35
0.15
SDL
0.70
SDL
SDL
0.25
0.05
Sun Sensor (Baffle & Optics) Assembly
SDL
1.15
Optics Module Assembly
Far Optics Module Assembly
Near Optics Module Assembly
Mid Optics Module Assembly
SDL
SDL
SDL
1.60
1.60
0.20
SDL
SDL
SDL
SDL
SDL
SDL
SDL
SDL
SDL
Vendor
0.75
2.05
0.95
1.40
0.65
1.45
1.60
1.75
0.10
0.60
External Cables
48-0167 Signal 1
48-0168 Signal 2
48-0169 Data Acquisition
48-0170 Chopper
48-0171 Sun Sensor
48-0172 Release
48-0173 Position
48-0174 Motors
48-0175 Heaters
Internal Cables
48-0176 Signal 1
48-0177 Signal 2
48-0194 Data Acquisition
48-0195 Chopper
48-0198 Sun Sensor
48-XXXX Motors
48-0212 Heaters
Survival Heaters
Fasteners
0.05
0.40
SOFIE Insrument Unit Mass
SOFIE Electronics Unit Mass
SOFIE Conn, Fast, Cabling Mass
CBE Total Mass
Fore Optics Assembly
Primary Mirror
Spider Structure
Secondary Mirror
Structure Assembly
Titanium Isolators
Baseplate
Lower Housing
Aft Optics Bench
Upper Housing
Fore Optics Bench
Aperture Housing
Radiator Panel
Witness Mirrors
MLI
Mechanisms
Pinpuller
Hinge
SDL
SDL
Part / Sub-Assembly
Structure
PCB
DC-DC Converters
Motherboard
Wedge-loks
Producer
SDL
Vendor
Vendor
Vendor
Vendor
Mass (kg)
4.25
5.20
0.40
0.90
0.40
Connectors, Fasteners, Cabling
Vendor
Vendor
Vendor
Vendor
Vendor
Vendor
Vendor
Vendor
Vendor
1.00
1.10
0.50
0.15
0.40
0.15
0.30
0.35
0.25
Vendor
Vendor
Vendor
Vendor
Vendor
Vendor
Vendor
Vendor
Vendor
0.40
0.40
0.15
0.05
0.10
0.05
0.05
0.10
1.20
18.56
11.15
6.70
36.41
Vendor Specification
Model Prediction
Measured
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
31 - 31
SOFIE CDR October 7-8, 2004
Power Budget
SOFIE Orbital Power Budget
Sub-Assembly
12VSM
-12VSM
12V
-12V
5V
TE Coolers (3 stage) -65 C (Aver)
TE Coolers (3 stage) -65 C (Peak)
TE Coolers (3 stage) -40 C (Aver)
TE Coolers (3 stage) -40 C (Peak)
6.30
6.80
0.62
5.75
0.62
5.75
2.28
3.15
2.17
2.80
4.30
5.50
2.60
5.00
1.75
2.67
Average Powers
Peak Powers
0.62
5.75
0.62
5.75
9.83
12.55
6.97
9.20
5.00
6.00
1.90
2.50
0.65
0.90
0.89
8.21
0.89
8.21
14.04
17.92
9.96
13.14
CBE SC Bus Total Average Power
CBE SC Bus Total Peak Power
3.00
4.00
1.30
1.80
0.50
0.60
0.03
0.04
0.40
0.50
3.00
4.00
5.90
6.60
9.08
11.21
10.00
12.00
12.20
13.40
12.97
19.59
14.29
17.14
17.43
19.14
0.70
Average Powers
Peak Powers
Average Input Protect Circ Power
Peak Input Protect Circ Power
2.5V
7.00
8.00
Signal Cond. & Thermal Cont. (Aver)
Signal Cond. & Thermal Cont. (Peak)
Data Acquisition (Aver)
Data Acquisition (Peak)
Chopper Drive (Aver)
Chopper Drive (Peak)
Command & Data Handling (Aver)
Command & Data Handling (Peak)
Sun Sensor (Aver)
Sun Sensor (Peak)
Steering Mirror System (Aver)
Steering Mirror System (Peak)
Power Conditioning Efficiency
3.3V
2.8
4.2
74.11
107.57
Total Average SC Bus Elec Unit Power
56.34
Total Average TEC Power (W/O Converter Loss)
13.30
1. Average Power includes (Steering Mirror Peak Power)*(5.0 minutes/96 minutes)
2. Power conditioning efficiency based on an ~ 36V input
GATS
MEASURED
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
32 - 32
SOFIE CDR October 7-8, 2004
Orbital Power Profile
Instrument
Sub-system
Time after passing over North pole (minutes)
40
45
50
55
Latitude (deg)
42.65
61.6
80.55
80.5
61.55
0
5
10
15
20
25
30
35
90
71.05
52.1
33.15
14.2
4.75
23.7
56.34
56.34
56.34
53
53
53
56.34
56.34
56.35
57
56.34
17.27
0.5
74.11
17.27
0.5
74.11
17.27
0.5
74.11
17
0.5
70.5
17
0.5
70.5
17
0.5
70.5
17.27
0.5
74.11
17.27
0.5
74.11
17.27
0.5
74.12
18
8.1
83.1
17.27
0.5
74.11
60
65
70
75
80
85
90
95
42.6
23.65
4.7
14.2
33.15
52.1
71.05
56.34
56.34
53
53
56.34
56.34
56.34
57
56.34
17.27
0.5
74.11
17.27
0.5
74.11
17
0.5
70.5
17
0.5
70.5
17.27
0.5
74.11
17.27
0.5
74.11
17.27
0.5
74.11
18
8.1
83.1
17.27
0.5
74.11
90 Orbit average
SOFIE
Electronics unit
TECs (16) + Sun
Sensor electronics
Steering mirror
Sub-total
In eclipse
= Removed from orbit average for 95 min orbits
In eclipse
84
82
80
78
SOFIE
76
74
72
70
68
0
20
40
60
GATS
80
74.11
100
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
33 - 33
SOFIE CDR October 7-8, 2004
GATS
9/17/2004
9/3/2004
8/20/2004
8/6/2004
7/23/2004
7/9/2004
6/25/2004
6/11/2004
5/28/2004
5/14/2004
4/30/2004
4/16/2004
4/2/2004
3/19/2004
3/5/2004
2/20/2004
2/6/2004
1/23/2004
1/9/2004
12/26/2003
12/12/2003
MBits/day
180
120
80
Date
160
140
100
60
Resource
CDR/PDR Ratio
Mass
36.4 / 34.6 = 1.05
Power
74.1 / 83.5 = 0.89
Data
168 / 73.6 = 2.28
9/8/2004
8/8/2004
7/8/2004
6/8/2004
5/8/2004
4/8/2004
3/8/2004
2/8/2004
1/8/2004
12/8/2003
11/8/2003
10/8/2003
9/8/2003
8/8/2003
7/8/2003
SOFIE MASS CBE TRACKING
6/8/2003
Watts
45.00
40.00
35.00
30.00
25.00
20.00
5/8/2003
1/
1
2/ /200
1
3/ /20 3
1 0
4/ /20 3
1 0
5/ /20 3
1 0
6/ /20 3
1 0
7/ /20 3
1 0
8/ /20 3
1 0
9/ /20 3
10 1/2 0 3
/ 0
11 1/2 0 3
/ 0
12 1/2 03
/1 0 0
1/ /20 3
1 0
2/ /20 3
1 0
3/ /20 4
1 0
4/ /20 4
1 0
5/ /20 4
1 0
6/ /20 4
1 0
7/ /20 4
1 0
8/ /20 4
1 0
9/ /20 4
1/ 0 4
20
04
kg
Resource Tracking
SOFIE AVERAGE POWER CBE TRACKING
85.00
80.00
75.00
70.00
65.00
60.00
Date
SOFIE DAILY DATA DOWNLINK VOLUME CBE TRACKING
Date
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
34 - 34
SOFIE CDR October 7-8, 2004
Error Budgets
BUDGET
REQUIREMENT
EXPECTED PERFORMANCE
Radiometric
WC Band 15 (NOWEAK)
SNR = 3.0 x 105
SNR = 9.33 x 105 (Margin = 3.11)
Pointing
15 Arcseconds (1 Sigma)
over 0.5 seconds
<1 Arcsecond (0.5 Arcseconds)
Static
Alignment
0.5 ° to SC
3 Arcminutes CBE
Will be calibrated out on orbit!
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
35 - 35
SOFIE CDR October 7-8, 2004
Post-PDR System Changes
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
36 - 36
SOFIE CDR October 7-8, 2004
Changes since PDR
SMA Caging
Mechanism
Removed
Wedge
Removed
Radiator
Reshaped
Cable Ports
Relocated
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
37 - 37
SOFIE CDR October 7-8, 2004
Changes since PDR (cont)
Repositioned
in SC and
Radiator
Removed
Electronics
Power
Conditioning
Redesigned
Detector
Packages
now
Non-hermetic
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
38 - 38
SOFIE CDR October 7-8, 2004
System Technical Risks
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
39 - 39
SOFIE CDR October 7-8, 2004
Technical Risks
RISK ID = SOFIE_RISK_4
SOFIE depends upon an active pointing system to provide the required sun
pointing accuracy and precision. The active pointing and control system
algorithm may be unable to provide the required sun pointing accuracy and
precision and the science capability would be degraded.
CRITICALITY
Green
MITIGATION
Extensive prototype and protoflight testing will be conducted.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
40 - 40
SOFIE CDR October 7-8, 2004
System Technical Coordination
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
41 - 41
SOFIE CDR October 7-8, 2004
Technical Coordination – SDL Design Processes
•
•
•
Engineering Design and Development
– System Design
• QP0401
– Software Design
• QP0406
Document Control and Configuration Management
– Document Control
• QP0501
– Software Configuration Management
• QP0403, SOFIE Software Configuration Management Plan
– SDL to maintain up-down information flow
Waivers, Problem Failure Reports (PFR)
– QP1301
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
42 - 42
SOFIE CDR October 7-8, 2004
Technical Coordination – Internal Peer Review
•
•
Review follows Breadboard/Prototype design phase
– Includes SDL members both internal and external to SOFIE
– System and component level
Following review, design placed in configuration control
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
43 - 43
SOFIE CDR October 7-8, 2004
Technical Coordination – SDL Design Processes (cont)
SOFIE GENERAL DESIGN STANDARDS
Standards
SOURCE
PCB Design
- IPC 2221, IPC 2222
PCB Fabrication
- Class 3 of IPC 6011, IPC 6012, NASA GSFC S312-P-003
PCB Coupon Inspection
- To be performed by customer
SMT Assembly
- NASA-STD-8739.2
Hand Soldered Assembly
- NASA-STD-8739.3
Cable, Crimp, and Harness
- NASA-STD-8739.4
Conformal Coating
- SDL Internal Process
ESD
- SDL Internal Process
Mechanical Torque
- SDL Internal Process
GATS
MAP, GDRD
MAP, GDRD
MAP, GDRD
SDL QW0915
SDL QP1503
SDL QW0914
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
44 - 44
SOFIE CDR October 7-8, 2004
Documentation Status
Document
Status
SOFIE Level 3 Requirements
Mission Approved
SOFIE Specifications Document
Released
SOFIE Flight Software Development Plan
Released
SOFIE Flight Software Specifications
Released
SOFIE Program Management Plan
Released
SOFIE Product Assurance Plan
Released
SOFIE Safety Plan
Released
SOFIE Contamination Control Plan
Baseline Released
SOFIE EEE and Materials Parts Lists
Controlled. Initial lists submitted to Mission November 2003
SOFIE Risk Management Database
Controlled
SOFIE Calibration Plan
Baseline Released
SOFIE Integration and Test Plan
Baseline Released
SOFIE Software Design Document and Test Plan
Baselines Released
SOFIE Electrical/Software ICD
Baseline Released
Subcontractor SOWs and ICDs
Released
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
45 - 45
SOFIE CDR October 7-8, 2004
SE Summary
•
•
•
Designs are mature and provide margin on system requirements
Technical resources are being managed and tracked
Error budgets are being managed
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
46 - 46
SOFIE CDR October 7-8, 2004
Supplementary Material
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
47 - 47
SOFIE CDR October 7-8, 2004
Radiometric System Requirements
Table 2. SOFIE spectral band specifications and channel S/N requirements.
SOF 174 :
Measurement Bands
SOF 183 :
Radiometric SNR
Band
Center 
(m)
Band Limits, m
Band Limits, cm-1
S/N*
O3 strong
0.290
0.2857 - 0.2941
34000 - 35000
1.0104
O3 weak
0.328
0.3226 – 0.3333
30000 - 31000
1.0104
particle
strong
0.862
0.8475 – 0.8772
11400 - 11800
1.0106
particle weak
1.03
1.0101 – 1.0526
9500 - 9900
1.0106
H2O weak
2.45
2.427 – 2.475
4040 - 4120
2.5104
H2O strong
2.60
2.577 – 2.632
3800 - 3880
2.5104
CO2 strong
2.77
2.740 – 2.794
3580 - 3650
3.0105
CO2 weak
2.94
2.907 – 2.967
3370 - 3440
3.0105
particle
strong
3.06
3.030 – 3.091
3235 - 3300
1.0105
particle weak
3.19
3.160 – 3.226
3100 - 3165
1.0105
CH4 strong
3.37
3.333 – 3.401
2940 - 3000
4.0105
CH4 weak
3.51
3.472 – 3.546
2820 - 2880
4.0105
CO2 strong
4.25
4.255 – 4.444
2250 - 2350
4.0105
CO2 weak
4.63
4.630 – 4.740
2110 - 2160
4.0105
NO weak
4.98
4.951 – 5.051
1980 - 2020
3.0105
NO strong
5.32
5.263 – 5.376
1860 - 1900
3.0105
*The effective noise bandwidth is 2 Hz.
Band limits are given in different units (cm-1 = 10000/m) but are otherwise identical.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
48 - 48
SOFIE CDR October 7-8, 2004
Radiometric Model Error Budget
Steering
Mirror
Telescope Aperture Diameter = 10.2 cm
Obscuration Diameter = 3.0 cm
Entrance Pupil Area = 74.0 cm2
Entrance Pupil FOV = 9.14-7 SR
Solar
Input
Telescope
Aperture
Diameter
Aperture
Cover
Secondary
Mirror
Obscuration
Diameter
Primary
Mirror
Entrance
Pupil Area
Chopping Factor (Modulation Form Factor) = 0.4
Radiometric Electrical Signal Bandwidth = 2 Hz
Radiometric Electrical Noise Bandwidth = 3.14 Hz
Detector Area = 0.01 cm2
Cassegrain
Telescope
Field Stop
4 SWIR Bands
(2.43 - 2.97 um)
Beamsplitters
4 UV,NIR Bands
(0.29 - 1.03 um)
4 SWIR Bands
(3.03 - 3.55 um)
4 LWIR Bands
(4.25 - 5.32 um)
Optical Input Path
Channel Separation
Module Assembly
Individual
Band Filters
Detector Assembly
(TEC, PreAmp)
NEP
and SNR
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
49 - 49
SOFIE CDR October 7-8, 2004
Radiometric Model Error Budget (cont)
Band Wavelengths =
wavelengths corresponding
bers of tableB
1
Band 1
Incident Detector Power =
1
1
0.294 0.286
1
0.011
1
1 3.8879·10 -6
2
0.333 0.323
2
0.017
2 1.0399·10 -5
0.877 0.847
3
0.305
3 4.1062·10 -4
4
1.053
1.01
4
0.409
4 5.2872·10 -4
5
2.475 2.427
5
0.614
5 6.5677·10 -5
6
2.632 2.577
6
0.596
6 5.8379·10 -5
7
2.793
7
0.617
7 4.8409·10 -5
3
2
2.74
Y  8 2.967 2.907
9
Band 16
System Transmittances =
m
  8 0.614
A  8 4.3974·10
-5
9 3.9877·10
-5
3.091
3.03
9
10 3.226
3.16
10 0.594
10
3.469·10 -5
11 3.401 3.333
11 0.581
11
3.196·10 -5
12 3.546 3.472
12 0.588
12
13 4.444 4.255
13
14 4.739
4.63
14 0.607
14
15 5.051
4.95
15 0.445
15 6.9515·10 -6
16
16 1.0554·10 -5
16 5.376 5.263
NEP =
0.639
2.566·10 -5
13 3.4048·10 -5
0.63
0.47
SNR =
1.718·10 -5
SN Margin =
1
1
1 9.844·10 -14
1
3.949·107
1
3.949·10 3
2 9.844·10 -14
2
1.056·108
2
1.056·10 4
3 2.953·10 -13
3
1.39·109
3
1.39·103
4 1.772·10 -13
4
2.984·109
4
2.984·10 3
1.79·10 -11
6 1.611·10 -11
5
3.669·106
5
146.771
6
3.624·106
6
144.958
7 6.329·10 -12
7
7.649·106
7
25.497
5
NEP  8 5.538·10
1
SR  8
7.941·106
Margin  8
26.471
9 1.477·10 -11
9
2.7·10 6
9
27.005
10 1.266·10 -11
10 2.741·106
10
27.407
11 1.042·10 -11
11 3.066·106
11
7.665
12 4.663·10 -12
12 5.503·106
12
13.757
13 5.212·10 -12
13 6.533·106
13
16.332
14 3.878·106
14
9.695
1.02·106
15
3.4
16 1.608·106
16
5.36
14
-12
4.43·10 -12
15 6.815·10 -12
16 6.563·10 -12
W
15
W
System Transmittances includes a linear
multiplication of appropriate mirror and filter
transmittance, reflection, and absorption (due
to end of life contamination) coefficients.
GATS
Optical Math Model Transfer Function
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
50 - 50
SOFIE CDR October 7-8, 2004
Radiometric Model Error Budget (cont)
Electronics Path
Phase Sensitive Detector
(Synchronous Recitification)
PreAmp
Signal Conditioning
SWITCHING
DEMODULATION
Front End
BPF (1 kHz)
LPF (12.8 Hz)
G =1
G
Balance
Attenuation
LPF (12.8 Hz)
Demodulation and Signal Conditioning
System Equivalent LPF = 10Hz
A
G = -1
Ground Processing
(2 Hz Information Bandwidth,
3.14 Hz Effective Noise Bandwidth)
Demodulated
Signal
Data Acquisition
1us Resolution
Phase Reference
Detector Channel Pair
Detector
Band A
Chopped (1 kHz)
Optical Input
Signal Conditioning
Optical
Chopper
(1 kHz)
Chopper Reference
Signal Phase Control
Balance Attenuation
Controlled Externally
G
Detector
Band B
14-bit ADC
Differential
Amp
LPF (12.8 Hz)
LPF (2.15 kHz)
MUX
x1
u1
Chopper Drive
Control
20 Hz Sampling Rate
32 X Oversampling
Bit Resolution = 366uV
LPF Settling to 12 RC Constants
Front End
PreAmp
BPF (1 kHz)
LPF (12.8 Hz)
G =1
G
Balance
Attenuation
LPF (12.8 Hz)
A
G = -1
SWITCHING
DEMODULATION
Signal Conditioning
Demodulated
Signal
Phase Sensitive Detector
(Synchronous Recitification)
GATS
Effective Sync Rect Q = 500
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
51 - 51
SOFIE CDR October 7-8, 2004
Radiometric Model Error Budget (cont)
Band /
Detector Type
1 / PV
2 / PV
3 / PV
4 / PV
5 / PC
6 / PC
7 / PC
8 / PC
9 / PC
10 / PC
11 / PC
12 / PC
13 / PC
14 / PC
15 / PC
16 / PC
SNR
3.14 Hz bw
5.81E+06
7.19E+06
8.38E+06
8.38E+06
3.59E+06
3.54E+06
6.79E+06
6.94E+06
2.65E+06
2.68E+06
2.98E+06
4.87E+06
5.39E+06
3.11E+06
9.33E+05
1.48E+06
GATS
Required
SNR
1.00E+04
1.00E+04
1.00E+06
1.00E+06
2.50E+04
2.50E+04
3.00E+05
3.00E+05
1.00E+05
1.00E+05
4.00E+05
4.00E+05
4.00E+05
4.00E+05
3.00E+05
3.00E+05
Margin
581.40
719.42
8.38
8.38
143.53
141.58
22.64
23.14
26.48
26.77
7.44
12.17
13.47
7.77
3.11
4.92
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
52 - 52
SOFIE CDR October 7-8, 2004
Pointing Model Error Budget
IDENTIFIER
SHORT DESCRIPTION
REQUIREMENT
(Pointing)
SOF 300
Pointing Ability
SOFIE shall point the center of its FOV to ±1 arcminute
at a fixed distance relative to the solar top edge
centerpoint and maintain this position during occultation
measurement.
The pointing position will be considered "maintained" if a
10 Hz filtering (0.1 sec running mean) of the true
pointing position varies <15 arc seconds (1 sigma) in
elevation and <1.0 arcmin (1 sigma) in azimuth.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
53 - 53
SOFIE CDR October 7-8, 2004
Pointing Model Error Budget (cont)
•
•
2D derived by hand, includes 1 mode in mirror and 1 mode in structure (4 plant states)
Integrates OSC’s latest S/C model (from AIM Bus CDR) and SSG’s latest SMA model
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
54 - 54
SOFIE CDR October 7-8, 2004
Pointing Model Error Budget (cont)
Error/Disturbance Source
Sun Sensor Noise
SMA DIT Sensor Noise
SMA DIT Thermal Drift
SMA Bit Resolution
Timing Error
S/C Disturbance
Value
0.5 arcsec (1-σ)
0.2 arcsec (1-σ)
26.88 arcsec/ºC
0.7 arcsec
1 msec (1-σ)
varies (see plot)
Description
White noise up to 2 Hz
White noise up to 10 kHz
slope
14-bit A/D
White noise up to 50 Hz
supplied by Orbital
25
20
15
S/C Motion (arcsec)
10
5
0
-5
-10
-15
-20
-25
0
5
10
GATS
15
20
25
Time (sec)
30
35
40
45
50
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
55 - 55
SOFIE CDR October 7-8, 2004
Pointing Model Error Budget (cont)
Description
Two-D simple model
with 4 states
Jitter in Sun
Elevation
Position
(arcsec, 1σ)
Jitter in Sun
Azimuth
Position
(arcsec, 1σ)
S/C Reaction
Torque in Elev.
Plane (N-m, 1σ)
0.499
N/A
0.0001
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
56 - 56
SOFIE CDR October 7-8, 2004
Alignment Knowledge Error Budget – SOFIE FOV to ROS
Instrument Unit
Optical Alignment Process
Steering Mirror Assembly
Steering Mirror
Positioning Sensor
Fix Steering Mirror,
Telescoping, Mirrors, Filters,
Field Stop, and Chopper
Pinpuller
Mechanism
Steering
Mirror
±10 mils = ±1 ArcMin
Solar
Input
Pinpuller
Mechanism
Alignment
Cube
Sun Sensor
Pickoff Mirrors
Fore Deck
Mid Deck
Aft Deck
Secondary
Mirror
±15 mils = ±1.5 ArcMin
Neutral Density Filter
Spectral (700 nm) Filter
Aperture
Cover
7 ArcSec Resolution
Primary
Mirror
Cassegrain
Telescope
Sun Sensor Baffle
Co-Align Detectors
and Sun Sensor with
Pin Spot Source
Field Stop
Chopper
Finish Instrument
Assembly
4 SWIR Bands
(2.43 - 2.97 um)
±25 mils = ±2.5 ArcMin
Beamsplitters
Focal Plane
Array
4 UV,NIR Bands
(0.29 - 1.03 um)
Sun Sensor
Processor
Sun Sensor
Housing Assembly
Co-Align Detectors/Sun Sensor
to Alignment Cube with
Theodolites/Columated Source
4 SWIR Bands
(3.03 - 3.55 um)
4 LWIR Bands
(4.25 - 5.32 um)
Channel Separation
Module Assembly
Individual
Band Filters
Detector Assembly
(TEC, PreAmp)
±25 mils = ±2.5 ArcMin
15 ArcSec Resolution
SOFIE Instrument Pointing Knowledge Budget
Initial Mechanical Alignment due to Tolerancing
7.5 ArcMin Worst Case
Alignment after Optical Alignment Process
22 ArcSec Worst Case
Spacecraft Pointing Knowledge Requirements
SOF231
The SOFIE optical axis shall be aligned to the spacecraft optical axis with an accuracy of ±0.25° prior to launch. This
alignment will be maintained to within ±0.5° on orbit.
From
MRD SYS837
SOF292
The SOFIE reference axis alignment to the observatory reference axis shall be known to better than +/-10 arcsec.
From
MRD SYS753
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
57 - 57
SOFIE CDR October 7-8, 2004
Alignment Knowledge Error Budget – Slow Thermal Dynamic
Simulation of Hot Case Conditions
•
Assumptions
–
–
Hot case thermal loads considered
Restrained temperatures:
•
•
•
•
•
•
•
•
•
•
–
–
–
–
CSM Assembly – 37 F to 48 F
Radiator Interface – 24.5 F
Aft Optics Deck – 30 F to 37 F
Fore Optics Deck – 25 F to 32 F
Bottom Deck – 32 F to 35 F
Sun Sensor – 39 F to 43 F
Mid Optics – 39 F
M1 and Hub – 34 F
M2 and Mount – 52 F
Isolator interface at S/C – 86 F
Only conduction heat transfer
considered
Steady-state temperature predicted
Displacements from 70 F
Displacements relative to Field Stop
GATS
Node
Displacement (in)
Rotation (Degrees)
X
Y
Z
X
Y
Z
Mirror
81101
M2/SS1
-1.5E-3
-2.7E-3
-1.2E-3
-8.1E-5
-2.8E-5
-9.7E-6
106497
Chop
-3.8E-4
4.0E-5
1.7E-6
-4.0E-6
-1.2E-6
-1.5E-5
106510
M3
1.7E-5
3.8E-4
-1.4E-4
-2.4E-6
-1.2E-5
7.0E-6
106520
Field
Stop
0
0
0
0
0
0
107175
SS2
-3.0E-5
-1.1E-3
-1.1E-3
-8.1E-5
-3.2E-5
8.9E-6
116912
SS4
-2.4E-4
7.5E-4
1.9E-6
-7.8E-5
-3.9E-5
1.8E-5
116922
SS3
-1.1E-3
2.1E-3
1.7E-4
-1.2E-4
-4.3E-5
3.2E-5
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
58 - 58
SOFIE CDR October 7-8, 2004
Alignment Knowledge Error Budget – Slow Thermal Dynamic
Simulation of Cold Case Conditions
•
Assumptions
–
–
Hot case thermal loads considered
Restrained temperatures:
•
•
•
•
•
•
•
•
•
•
–
CSM Assembly – -27 F
Radiator Interface – -35 F
Aft Optics Deck – -26 F
Fore Optics Deck – -31 F
Bottom Deck – -30 F
Sun Sensor – -27 F
Mid Optics – -25 F
M1 and Hub – -28 F
M2 and Mount – -26 F
Isolator interface at S/C – -4 F
–
–
Only conduction heat transfer
considered
Steady-state temperature predicted
Displacements from 70 F
–
Displacement relative to Field Stop
GATS
Node
Displacement (in)
Rotation (Degrees)
X
Y
Z
X
Y
Z
Mirror
81101
M2/SS1
-1.1E-3
-1.4E-3
-2.5E-4
-1.4E-5
-1.5E-5
1.0E-5
106497
Chop
-2.7E-4
2.7E-5
-1.8E-6
7.2E-6
-2.1E-7
-1.3E-5
106510
M3
4.5E-5
2.3E-4
-7.3E-5
-1.6E-5
-8.6E-6
-1.1E-6
106520
Field
Stop
0
0
0
0
0
0
107175
SS2
-2.1E-4
-9.3E-4
-2.7E-4
-1.2E-5
-1.8E-5
1.8E-6
116912
SS4
-1.6E-4
5.4E-4
1.6E-5
-1.2E-5
-4.1E-6
-2.5E-6
116922
SS3
-7.9E-4
1.4E-3
2.0E-4
-2.1E-5
-4.3E-5
5.2E-7
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
59 - 59
SOFIE CDR October 7-8, 2004
Alignment Knowledge Error Budget – Slow Thermal Dynamic
Simulation of SOFIE to SC Deflections
Node in center of Aperture Cover (SOFIE FEM coordinate system)
Hot Case:
Cold Case:
Tx:
Ty:
Tz:
Rx:
Ry:
Rz:
Tx:
Ty:
Tz:
Rx:
Ry:
Rz:
GATS
3.03e-4 in
-6.05e-3 in
-8.46e-3 in
-2.14e-4 degrees
5.39e-5 degrees
-4.41e-5 degrees
6.00e-4 in
-1.82e-2 in
-1.99e-2 in
-6.77e-4 degrees
6.92e-5 degrees
-3.87e-5 degrees
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
60 - 60
SOFIE CDR October 7-8, 2004
Pointing Budget – SOFIE to SC Accuracy
SOFIE Science
FOV Boresight to
Sun Center
(SYS755)
Required 60
RSS
SOFIE Science
FOV Boresight to
ROS Error
SOFIE ROS to S/C
Deck I/F Plane
Error
CBE 0.4
(SOF231)
Required 30
SOFIE ROS to S/C
Deck I/F Plane
Static Error
SOFIE ROS to S/C
Deck I/F Plane Slow
Dynamic Error
SOFIE ROS to S/C
Deck I/F Plane
Launch Shift
CBE 1
CBE 2
CBE 2
S/C Deck I/F Plane
to MRC Error
(SYS837)
MRC Pointing
Accuracy
(SYS844)
Required 2
Required 17
ACS Accuracy
(BUS272)
Ephemeris Error
(SYS844)
Required 5
Required 36
RSS = 3 Arcminutes (3 Sigma)
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
61 - 61
SOFIE CDR October 7-8, 2004
GFOV Clearance
9.53in.
Glint FOV
0.69in.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
62 - 62
SOFIE CDR October 7-8, 2004
Level 3 & 4 Requirements Compendium
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
63 - 63
SOFIE CDR October 7-8, 2004
AIM Science Objectives Traceability to SOFIE
Science Question
1. Morphology
2. GW Affects 3. Dynamics
4. H-chemistry
5. Nucleation
Geophysical Parameters Required to Answer Science Question
PMC
Morphology,
Particle Sizes
PMC
Morphology
SOFIE
Observation
PMC
Morphology
PMC
Morphology
PMC
Morphology
Cloud
Extinction
Temperature
Profile
T,CO2
Profiles,
Circulation
Temperature
Profile
Temperature
Profile
CO2
Absorption
H2O Profile
H2O Profile,
Circulation
H2O Profile
H2O Profile
H2O
Absorption
CH4 Profile,
Circulation
O3 Profile
O3 Absorption
CH4 Profile,
Circulation
CH4
Absorption
NO Profile
GATS
NO Absorption
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
64 - 64
SOFIE CDR October 7-8, 2004
Level 3 Requirements Management
•
•
•
•
Requirements will be utilized as the main method for defining the functionality,
performance, design constraints, and interfaces for the AIM program
Requirements will be used throughout all phases of the program to guide
design, development, integration, and test
Requirements tracking and compliance assurance will be an integral part of
peer, design, integration, and test reviews to insure that the system
development is proceeding in accordance with the systems engineering and
management process
After initial completion, the requirements and interfaces will baselined and
change tracking will occur:
– Access control will allow those teams and individuals with responsibility for
portions of the requirements to propose changes to those requirements.
– The system engineering team will work with the necessary engineers and
management personnel to access the impact of requirements changes on the
remainder of the system.
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
65 - 65
SOFIE CDR October 7-8, 2004
Level 3 Requirements Management (cont)
AIM Requirements Traceability & Specification Tree (from AIM SEMP)
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
66 - 66
SOFIE CDR October 7-8, 2004
Level 3 Requirements Management (cont)
AIM Requirements Development Approach and Guidelines (from AIM SEMP)
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
67 - 67
SOFIE CDR October 7-8, 2004
Level 3 & 4 Requirements Management (cont)
•
•
•
•
•
SOFIE Level 3 requirements derived from AIM Level 1 & 2 requirements
– Level 3 requirements report (DOORS) created in accordance with WBS
– Approved by AIM Mission systems engineer and Deputy SE
Level 3 requirements managed by SOFIE systems engineer
– Level 3 requirements assigned to appropriate discipline leads
Level 4 requirements derived from Level 3 requirements by systems
engineer and discipline leads
– Subcontractors requirements are also managed as Level 4
Level 3 and Level 4 requirements derivation includes source traceability and
verification process information
– Serves as Verification Matrix
SOFIE Instrument Specifications and SOFIE Flight Software Specifications
captured in SDL/04-004 and SDL/04-003, respectively
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
68 - 68
SOFIE CDR October 7-8, 2004
Level 3 Verification Matrix
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
69 - 69
SOFIE CDR October 7-8, 2004
Level 3 Verification Matrix (cont.)
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
70 - 70
SOFIE CDR October 7-8, 2004
Level 3 Verification Matrix (cont.)
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
71 - 71
SOFIE CDR October 7-8, 2004
Level 3 Verification Matrix (cont.)
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
72 - 72
SOFIE CDR October 7-8, 2004
Level 3 Requirements Database
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
73 - 73
SOFIE CDR October 7-8, 2004
Level 4 Requirements Database
GATS
Systems Engineering,
SOFIE Chad
PDRFish
– October 22, 2003
74 - 74
SOFIE CDR October 7-8, 2004