Title: MINRAD Research on Miniaturized Radiometry
1MINRADResearch on Miniaturized Radiometry
- Critical Design Review
- 13 January 2000
2Agenda
- 0930 Welcome and Opening Remarks
- 0940 The MINRAD Program
- 1000 Radiometer Optics
- 1040 Radiometer Mechanical Design
- 1200 System Electronics
- 1240 Payload Control
- 1320 Schedule and Program Status
- 1330 Closing Review Action Items
- Dr. James Russell III / HU
- Dr. Scott Bailey / HU
- Dr. Mark Larsen / USU
- Dr. Ralph Haycock / USU
- Mr. Wayne Sanderson / USU
- Mr. Timothy Green / HU
- Ms. Gbemi Munis / HU
- Mr. Richard Wright / HU
- Mr. Peter Mace / USU
- Mr. James Ulwick / USU
Informal group discussions following the meeting,
1400-1500, or as time allows.
3The MINRAD Program
- Dr. Scott Bailey
- Center for Atmospheric SciencesHampton
UniversityHampton, VA 23668 - Phone (757) 728-6936Fax (757) 727-5090
- E-mail Scott.Bailey_at_HamptonU.EDU
4Program Goals
- We wish to develop advanced, innovative,
miniature, infrared sensors for investigations of
atmospheric infrared backgrounds. - We will actively involve students and faculty
from Hampton University and SDL/USU in research
and technology using spaced-based sensors.
5Scientific Goals
- Provide improved understanding of the
relationship between eddy diffusion and airglow
emissions by performing sounding rocket
measurements of O2(1?) emissions, OH Meinel
emissions, and electron density. - temporal changes, baseline OH chemistry,
turbulent velocity, energy dissipation rate, and
eddy diffusion processes - Perform synergistic science studies of temporal
and spatial airglow variations using the
combination of MINRAD and TIMED SABER satellite
data.
6The Team
7The Team
- As an affiliated research center for BMDO for
research and technology in areas of sensors and
space surveillance, Space Dynamics Laboratory
(SDL) is leading the way in miniaturizing the
radiometer for this project. PI Mr. James Ulwick
is a pioneer in upper atmospheric exploration. He
is leading the miniaturization initiative to help
BMDO reach its goals and objectives through new
technologies at lower costs. - Hampton University (HU) has two leading
atmospheric scientists committed to measuring and
understanding the mechanisms exciting atmospheric
species. PI Dr. James Russell III has extensive
experience at NASA, has been PI of numerous space
borne IR remote sensing instruments, and is
currently PI of the SABER experiment on the TIMED
spacecraft. HU, a historically black
college/university (HBCU), is committed to
developing a premier program in atmospheric
sciences. Co-I Dr. Scott Bailey has successful
experience leading students on NASA remote
sensing missions. - SPAWAR Systems Center San Diego - Mission is to
be the pre-eminent provider of integrated C4ISR
solutions for warrior information dominance. Dr.
Clifton Phillips, assistant technology agent for
multisensor tracking and optical target
characterization, is monitoring this work.
8BMDO Goals and Objectives
- The Ballistic Missile Defense Organization
(BMDO) is tasked with providing a missile defense
system to protect the U.S., its forces deployed
abroad, and its friends and allies against
accidental, unauthorized, and limited ballistic
missile strikes. The agency has three mission
focus areas. - The first priority is to develop and deploy
increasingly capable Theater Missile Defenses
(TMD) to meet existing missile threat to deployed
U.S. and allied forces. (Emerging threats include
cruise missiles.) - The second priority, as a hedge against the
emergence of long-range ballistic missile
threats, is to develop options to deploy a
National Missile Defense (NMD) for the United
States. - The third priority is to continue supporting
research on more advanced ballistic missile
defense technologies to keep pace with the threat
and improve the performance of theater and NMD
systems.
9Technical Objectives
- Develop radiometers that take advantage of orders
of magnitude lower cost delivery systems. - This makes atmospheric research routine and
cheap. - Small size and weight goals make the miniaturized
radiometer sensor attractive for sensor suites
aboard other platforms such as aircraft, UAV,
extended seeker capabilities, and portable ground
stations. - Exploit development campaign for low cost Viper
IIIA/DART delivery system by using it as
development platform and baseline packaging
constraint. - Viper/DART serves as the role model in reduce
sounding rocket lifecycle cost. - Development of the experiment launch platform is
funded by SDL internal research and development. - Package two-channel radiometer into a two-inch
diameter payload compartment. - Develop miniaturized sensor management and
housekeeping functions. - Facilitate easy growth path to cryogenic upgrades.
10Science Objectives
- Contribute to the overall atmospheric optical
characterization goals of BMDO. - Quantitatively test temporal changes in the
relationship between O2(1?) airglowand O3
concentration. - Address the baseline chemistry of OH using rocket
and ground based measurements. - Derive turbulent velocity, energy dissipation
rate, and eddy diffusion coefficients in middle
atmosphere using spectral information from
electron density fluctuations. - Study relationship between eddy diffusion and
airglow using photometer, radiometer and atomic
oxygen measurements compared to 1-D kinetic
transport model predictions. - Perform synergistic science studies and define
temporal changes using miniature radiometer
measurements and similar measurements from
complementary NASA spacecraft (i.e. TIMED). - Extract clear understanding of atmospheric
generated clutter.
11How MINRAD Helps BMDO
- Directly addresses BMDOs need to identify and
understand atmospheric IR background clutter. - Develops miniaturized sensor technology for the
measurement of clutter. - Enhances scientific understanding of the
processes creating clutter. - Miniaturized and rugged radiometry expands the
range of available launch vehicles allowing
rapid, inexpensive, and reliable access to space
for the testing of new sensor technology. - Supports upgrade path for interceptor, seeker,
and space based sensor technologies (miniaturized
radiometry provides reduced weight and presents
minimal impact on maneuverability and
performance). - Potential use for verification of background
clutter in local theater of operations.
12Development Path(Smaller-Lighter-Cheaper)
BMDO Capability
Surveillance Sensor
Miniature Cryogenic Sensor (l,mass optimized)
Technology / Hardware Trend
Miniature Cryogenic Sensor (LWIR)
Miniature Near IR Sensor (current work)
Large Cryogenic Sensor (large mass)
Time
Current Technology
MINRAD Phase III
Broadband Spectral Ability
Enhancement Infusion
MINRAD Near Term
13MINRAD Exploits Developed Low cost Launch Vehicles
- Provides significant cost reductions for science
platforms because smaller and lighter payloads
can be flown on lower cost launch vehicles. - Lower cost science platforms allow more
experiments to be flown to understand
temporal/spatial processes that create emissions
and provides expanded capability to meet
multi-spectral needs. - Miniaturization technologies can be implemented
now with low cost and risk.
10000
1000
100
Launch Vehicle Cost Relative to Viper DART
10
1
Terrier Malamute
Black Brant
Viper DART
Delta II
Pegasus
14Sample Flight Profile
15Radiometer Optics
- Dr. Mark Larsen
- SPACE DYNAMICS LABORATORYUtah State
University1695 North Research Park WayNorth
Logan UT 84341-1947 - Phone (435) 797-4337Fax (435) 797-4495
- E-mail Mark.Larsen_at_SDL.USU.EDU
16Outline
- Optical Design
- Model
- Optical, radiometric, electrical
- Sensitivity
- Detectors, NEP, SNR
- Background
- Instrument, solar, nose cone
17Optical Design Objectives
- Package length lt 5 in.
- Package footprint lt 1.5 in. x 1 in.
- Weight lt 1 lb.
- Acceleration load of 150 gs
- Unknown thermal shock
- SNR 50
- Full field of view 15 (achieve SNR)
18Mechanically ChoppedDouble Barrel Radiometer
- Features
- Two optical barrels
- Simple filters
- Advantages
- Low technology risk
- Disadvantages
- Moderate packaging difficulties
19Optical Design Characteristics
- Clear aperture 10 mm
- Full field of view 12
- Two spectral bands
- Band 1 1.263 ?m - 1.290 ?m (?? 27 nm)
- Band 2 1.463 ?m - 1.563 ?m (?? 100 nm)
- No vignetting
- Uniform detector irradiance
- Transmittance of optics 0.56
- Diameter of the detector 2 mm
20Optical Design Challenges
- Packaging
- Lens mounting for 150 g
- Baffling
21Optical Layout
22Band 1 Spot Diagrams
23Encircled Energy
24Radiometer Overview
25Radiometer Baffle
26Radiometric Model
27Electrical System
- Design to respond to frequencies higher than the
spin rate of the rocket (20 Hz) - Electrical noise bandwidth 50 Hz
- Chopping frequency 300 Hz
- EGG InGaAs thermoelectrically cooled detectors
operating at 10 ºC - Size 2mm, cutoff 1.7 mm, typical D 2.1e13
- NER 3.8e-12 w/cm2sr
- 362 Rayleighs in band 1
- 305 Rayleighs in band 2
28Instrument Background
- For a temperature of 20 ºC inside the sensor, the
background is - 6 in band 1
- 12 in band 2
29Background From Nose Cone
- Assuming the nose cone has a temperature of 200
ºC, the nose would cause an error of 5 at 50
meters if it is in the field of view. - Since we wont know the range to the nose, we
need to get it out of the field of view.
Band 1, Minimum cross section
30Non-Rejected Solar Radiance
- Given
- A coning angle of 5º, and a mean angle to the sun
of 80º. - The relative response of sensor at 80º is 10-8.
- Then the in-band non-rejected solar radiance
varies between approximately 12 and 30 of the
signal level in both bands.
31Summary
- SNR of 50 using existing detector technology.
- Background Signal (Noise) Reduction
- Get the nose cone out of field of view.
- Keep telescope optics and baffling at 20 ºC or
less. - Make angle to sun as large as possible and coning
as small as possible. - The optical design satisfies the requirements.
32Radiometer Mechanical Design
- Dr. Ralph Haycock
- SPACE DYNAMICS LABORATORYUtah State
UniversityUMC 4130Logan UT 84322-4130 - Phone (435) 797-2907Fax (435) 797-2417
- E-mail Ralph.Haycock_at_SDL.USU.EDU
33Topics
- Mechanical Assembly
- Payload Mounting
- Component Identification
- Component Mounting
- Isometric Views
- Exploded Views
- Section Views
- Mechanical Analysis
- Chopper blade
- Stresses due to
- Acceleration or Thrust
- Spin
- Vibration
- Thermal Analysis
- Future Testing and Analysis
34Payload Mounting
Radiometer
35Component Identification
36Component Mounting
37Isometric (Fore)
38Isometric (Aft)
39Isometric Exploded (Fore)
40Isometric Exploded (Aft)
Motor/Shaft Coupling
41Section Views
Section A-A Section
B-B Section C-C
42Analysis of theRadiometer Chopper Blade
- Axial acceleration or g loading
- Radial acceleration or spin loading
- Vibration
- Resonant frequencies
- Mode shapes
43Prototype Disk Analysis
- Material
- Aluminum 6061-T6 was used for the analysis and
testing. - Other material (stainless steel, spring steel,
etc.) may be considered in the final design. - Acceleration g loads
- Validation by measuring displacement under a test
load. - Rotating Loads
- Validated with a closed form solution of a solid
disk. - Vibration Loading
- Validation by identifying the resonant
frequencies in a prototype model.
44Acceleration or g Loading
- Contact between the chopper disk and structure
may result in no chopper rotation - Material
- 6061-T6 Aluminum
- Mass Density 26.6 KN/m3 (0.098 lb/in3)
- Acceleration load of 150 gs during launch
45Finite Element (FE) Model Displacement
- Found in the z direction (normal to the surface
of the disk) - Coarse and fine mesh FE models created to verify
convergence - Will be verified with actual measurements
46DisplacementCoarse Mesh FE Model
47DisplacementFine Mesh FE Model
48Finite Element (FE) ModelStress
- The stress level shown is for the top of the thin
shell element - Must be less than the fatigue stress for the
dynamic load and less than the yield stress for
the g loading - For 6061-T6 Aluminum
- Yield strength Sy 296 MPA (43 kpsi)
- Fatigue stress St 90 MPA (13 kpsi)
49StressCoarse Mesh FE Model
50StressFine Mesh FE Model
51Results
- Displacement
- Maximum displacement occurs at the outer edges
and is approximately 0.000283 inches - Stress
- Maximum occurs near the disk center
- Maximum stress of 1.1 kpsi is well below the
limit of 43 kpsi
52Spinning Blade Analysis
- A disk rotating at 9000 RPM or 150 Hz induces
body forces within the disk. - Displacement could lead to interference with
radiometer housing. - FEA was used to determine stress and displacement
for a thin disk with a hole in the center. - The disk was meshed as quadralinear Mindlin shell
elements using the IDEAS software. - Partial validation has been obtained through a
similar FEA with a closed form numerical solution.
53FEA of a Spinning Disk
54Closed Loop Solution for a Spinning Disk
55Analysis Results for a Spinning Disk
- The stress level for the exact solution and the
FE model are very close. - Both solutions used the same boundary conditions.
- Mesh refinement will reveal a closer relationship
between these two solutions. - Coarse mesh of the entire disk was compared to a
half section fine mesh model. - The entire disk model and half model where
compared to give validity to the fine meshed half
sections.
56DisplacementWhole Disk Coarse Mesh FE Model
57DisplacementHalf Disk - Fine Mesh FE Model
58StressWhole Disk Coarse Mesh FE Model
59StressHalf Disk - Fine Mesh FE Model
60Results
- Displacement
- Max radial displacement of 9.11E-6 inches
- Stress
- Maximum von Mises stress of 241 psi
- Well below maximum yield stress of 43 kpsi and
the fatigue strength of 13 kpsi
61Vibration Analysis
- Examine the resonant frequencies in the axial or
z direction of the chopper disk. - FEA for initial predictions
- Test set up
- Refine the FE model
62Initial FEA of Disk
- Three fundamental mode shapes predicted
- First resonant frequency at 2040 Hz
- Second resonant frequency at 2600 Hz
- Third resonant frequency at 2830 Hz
- NOTE In the following pictures showing the mode
shapes,the FE model included the mounting shaft
below and thesensing accelerometer on top of the
disk.
63First Fundamental Mode
64Second Fundamental Mode
65Third Fundamental Mode
66FEA OutputFirst Resonant Frequency
67Vibration Testing
- Verify the FE model and the analysis.
- A large, 8 diameter, scale model was developed
to illustrate the vibration mode shapes. - Accelerometers were placed on the outer edges of
the disk.
68Test Chopper Disk
Accelerometer 1
Accelerometer 2
69Video Images From Vibration Tests
70Vibration Test DataAccelerometer 1
71Vibration Test DataAccelerometer 2
72Interpretation of results
- A very prominent resonant frequency at
approximately 200 Hz - Less prominent resonance around 160 Hz
- An FEA of the scale model predicted resonant
frequencies of 142, 155, and 193 Hz - The FEA of the scale model and the data from the
vibration test were in close agreement
73Future Testing and AnalysisChopper Blade
- Locate the resonant frequencies in the mounting
shaft - Determine the required preload in the jewel
bearing - Determine the friction in the jewel bearing
74Future Testing and AnalysisChopper Motor
- Torque curves
- Analysis of mounting cradle
- Vibration of motor and chopper assembly
- In the axial direction
- In the transverse direction
- Determine the startup time
- Moments of inertia
- Total friction of motor and jewel bearing
- g load on motor bearings due the mass of the
chopper, shaft, and rotor
75Future Testing and AnalysisRadiometer System
- Vibration Analysis and Testing
- Axial and transverse axes
- Determine the mounting and structural integrity
of the optical system - Find resonant frequencies
- g loading in axial and transverse axis
- Simulate thrust loading in a centrifuge
76Thermal Analysis
- Numerical Modeling
- FE models in IDEAS
- Finite difference modeling using SINDA
- Issues
- Heat transfer due to aero heating on nose cone
- Internal heating due to
- Chopper (motor inefficiency, bearing friction,
etc.) - Detectors (TE cooling, electronics, etc.)
77Description of FE ModelPreliminary Thermal Model
of Nose Cone
- 3D solid model of the nose tip and the nose cone
body - 10 section of model nose cone meshed
- Thin wall sections 0.006 square by 0.063 thick
- Initial conditions and boundary conditions
- Initial temperature of model set at 22 C
- Outside surface set at 500 C
78Sample FE ModelPreliminary Model of Nose Cone
79SINDA Analysis
- SINDA is a comprehensive finite-difference,
lumped parameter (circuit or network analogy)
tool for analyzing complex thermal systems. - SINDA offers steady-state and transient
solutions. - SINDA allows a second approach to the numerical
modeling for verification of FE model developed
under IDEAS.
80Future Testing and AnalysisThermal
- FE and SINDA Modeling
- Nose cone
- Examine and minimize heat transfer to radiometer
housing, prior to nose cone ejection - Motor
- Verify sufficient heat sink for motor operation
- Verify isolation to prevent motor heat from
reaching detectors - Detectors
- Model and optimize heat transfer to aid in
detector cooling
81Summary
- Tasks have been identified and team members have
been assigned to program - Structural analysis and prototype fabrication has
started - Thermal issues have been identified and the
analysis has started - Test hardware has been ordered and testing is
currently underway on motors and bearings
82System Electronics
- Wayne Sanderson
- SPACE DYNAMICS LABORATORYUtah State
University1695 North Research Park WayNorth
Logan UT 84341-1947 - Phone (435) 797-4572Fax (435) 797-4495
- E-mail Wayne.Sanderson_at_SDL.USU.EDU
83Overview
- Payload Overview
- Electronics by Sections
- Tail section
- Aft section
- Mid/Battery section
- Forward section
- Instrument section
- Radiometer Electronics
- Summary of Instruments
84Payload Layout
85Design Goals
- Smaller
- Surface mount components
- Blind Assembly
- Modular design
- Plug and play
- Bulkhead and motherboard
- Keep Pin Count Down
- Common control lines
- Split controllers
- Low Power (Primary Cells)
- Select low power devices where possible
- Use DC/DC converter to improve efficiency
- Flexibility
- Modular PC boards
- FPGA controllers
86Aft Section Layout
87Transmitter Section
- Transmitter
- L3 Communications T-401S
- 1 watt output
- 2279.5 MHz (S-band)
- 800 Kbps
- Antenna
- Slotted tail fin coupled with RF matching network
provides circular polarization - Temperature Sensors
- Transmitter 0-150 ºC, 195 samples/sec
- Tail Skin 0-300 ºC, 195 samples/sec
88Accelerometer/Pressure/Umbilical
- Accelerometer Z (Thrust)
- 150/-50 g
- 1562 samples/sec
- Accelerometer X1 (Off-axis)
- 100 g
- 1562 samples/sec
- Accelerometer X2 (On-axis)
- 25 g
- 1562 samples/sec
- Pressure
- 0-30 psi
- 195 samples/sec
- Umbilical Interface
89Power PCB
- Internal/External Power Switching
- GPS Power and Interface
- System DC/DC Converter
- DC/DC Temperature
- 0-150 ºC
- 195 samples/sec
- Battery Bus Voltage
- Umbilical (analog)
- Real time safety monitor
- Battery Bus Voltage
- 23-33V
- 195 samples/sec
- Battery Bus Current
- 0-1A
- 195 samples/sec
90GPS PCB
- Global Positioning Receiver
- Rockwell Jupiter model
- Data rate 1200 words/sec
- Pseudo range operation
- Reset position at launch for faster acquisition
91Aft Instrument PCB
- Main Control
- PCM data formatter
- Payload controls
- FPGA based
- Pyrotechnic Release
- Firing circuit
- NASA design
- DC/DC Monitors
- 4.5 to 5.5V _at_ 195 SPS
- 11.5 to 12.5V _at_ 195 SPS
- -12.5 to -11.5V _at_ 195 SPS
- Temperature Monitors
- Printed circuit board
- Aft battery pack
- Bulkhead
- Signal Conditioning
- Temperature monitors
- Voltage monitors
- 3 axis magnetometer
92Mid Section Layout
93Mid Section Components
- Aft Battery Pack
- 28 V _at_ 1 AH
- Fore Battery pack
- 6 V _at_ 5 AH
- Magnetometer
- 3 axis _at_ 2 Gauss
- 195 SPS
- GPS Antenna
- 2 patch antennae
- Diametrically opposed
- GPS Preamplifier
- Temperature Monitor
- 0-150 ºC _at_ 195 SPS
94Fore Section Layout
95Pyrotechnic Mount PCB
- Forward Battery
- Internal power switch
- Voltage monitor
- Current monitor
- Signal Conditioning
- Temperature monitors
- Forward battery monitors
- Radiometer Monitors
- TE temperature
- TE voltage
- Motor voltage
- Motor current
- Motor speed
- Mount for Release Pyro
96Forward Instrument PCB
- Forward Multiplexer
- Forward A/D Converter
- PCB Temperature
- 0-150 ºC _at_ 195 SPS
- Forward Skin Temperature
- 0-300 ºC _at_ 195 SPS
- Radiometer
- Signal conditioning
- Motor control
- TE control
- DC Probe
- Secondary Digital Controller
97Instrument Section
98Instrument Section
- DC Probe
- Ring antenna
- Preamplifier
- Radiometer Detectors
- InGaAs detectors
- Preamplifiers
- TE cooler
- Radiometer Instrumentation Amp
- Chopper Motor/Encoder
- Temperature Monitors
- 0-150 ºC _at_ 195 SPS
- Baffle
- Motor
- TE Heat sink
99Radiometer Electronics
100TE Temperature Control
101Chopper Control/Rectifier Sync
102Digital Controls
- Launch Recognition
- Power Switching
- Digital Monitors
- A/D Control
- SYNC/SFID
- Chopper Control
- Rectifier Signal Delay
- Serial Data Output
- Bi-?-L Control
- GPS Control
- UART initialization
- DATA control
- PCM Control
- Data matrix
- MUX control
- A/D enable
103Payload/Instrument Summary
104Projections
- Through the use of surface mount devices and
programmable logic, board space required for DART
electronics is approximately 36 in2. - Runtime for the battery packs (internal
power).
(Based on 40 ºC detector temperature) - Digital controls are easily reconfigured through
the use of programmable logic, limiting the need
to redesign the PC boards.
105Payload Control
- Hampton UniversityCenter for Atmospheric
SciencesElectrical Engineering Department - Timothy Green
- E-mail temitope39_at_hotmail.com
- Charles Hill
- E-mail Charles.Hill_at_HamptonU.EDU
- Gbemi Munis
- E-mail gbemisola_at_hotmail.com
- Richard Wright
- E-mail nrplongisland_at_hotmail.com
106Objectives
- Hampton University will design and implement the
software for embedded control of the rocket
payload. This includes data sampling and
formatting, chopper motor control, and handling
of the payload telemetry. - The software will be programmed into a Field
Programmable Gate Array (FPGA) logic device. - Hampton University will assemble a complete
rocket payload assuming funds are made available.
107Tasks
- Software Component Design Implementation
- Fore Section Embedded Logic Control
- Aft Section Embedded Logic Control
- PC-Based Decoder
108Payload/Instrument Summary
109Requirements
Digital Signals
Housekeeping
Science Sensors
Temperature Acceleration Pressure Battery Voltage
and Current Motor Voltage and Current
GPS, Digital Monitors
Optical Devices Langmuir Probe Radiometer
Field Programmable Gate Arrays
Chopper Motor Control
Telemetry
110Telemetry Matrix
Bit Rate 800 Kbps Word Rate
50000 wps Sub-frame Rate 1562.500
sfps Major Frame Rate 195.310 fps
111Field Programmable Gate Arrays
- Appropriate When Space Is Limited
- A large collection of discrete logical components
are replaced by a significantly smaller package. - Reduced Power Consumption
- FPGAs offer reduced power consumption as
compared to boards populated by an equivalent,
discrete logic circuit. - Speed
112Field Programmable Gate Arrays
- Reprogram in the Field
- Software enhancements may be added quickly and
easily without removing the device from the
rocket. - Wide Product Selection
- There is currently a wide and flexible range of
FPGA products commercially available.
113Device Selection
- Altera MAX 7000 Device Family
- Free educational kit that includes a design
laboratory package. - Minimal resourcesneeded to get started.
114Design Laboratory Education Board
115Altera Hardware Description Language
- AHDL Uses Concurrent Logic
- AHDL is a text entry language for describing
logic designs. - AHDL is a concurrent language. Each line of
source code is evaluated at the same time rather
then sequentially. - Examples of Source Code to Follow
- Logic Circuitry (e.g. AND Gate, OR Gate, etc.)
- Graphic Version of Source Code Is Always Possible
116AND Declaration(AHDL Concurrent Logic)
SUBDESIGN GATE( a,b INPUT c OUTPUT)BEGIN
c a AND bEND
GATE
117OR Declaration(AHDL Concurrent Logic)
SUBDESIGN GATE2( a,b INPUT c OUTPUT)BEGIN
c a OR bEND
1182 to 1 Multiplexer(AHDL Concurrent Logic)
SUBDESIGN MUX2TO1( pressure, temperature,
address INPUT converter OUTPUT)BEGIN IF
address 1 THEN converter temperature ELSIF
address 0 THEN converter pressure ENDIFE
ND
119Fore Section Altera
ALTERA
A/D
MUX 41
MUX 161
MUX 161
120Aft Section Altera
Data From Fore Section Altera
MUX 41
A/D
Aft Altera
MUX 161
Serial Data Stream
SENSORS
GPS Data
121Typical System Flow
Chopper Motor Driver and Encoder
Science
Optical Devices, Langmuir Probe, Signal
Output, Radiometer
Fore Altera
Sensor Sampling Sequence Control
Housekeeping
Temperature, Acceleration, Pressure
Analog MUX
A/D
Aft Altera
GPS
Read/Write
Transmitter
122PC-Based Decoder
- Used for verification of data stream
- Recover of analog values in real-time
- Software/Hardware yet to be purchased (COTS)
123Software Simulation
- Altera software provides I/O simulation
capability - software verification
- timing analysis
124Chopper Motor Control
Chopper
Aft Altera
Fore Altera
Motor Encoder
Chopper Motor
Chopper Driver
Pulse Width Modulation
DC Voltage
125Telemetry PCM Code
- Manchester Non-Return-to-Zero (NRZ).
- Also known as Bi-?-L (bi-phase L).
- Relatively inexpensive circuitry may be used
throughout the system. - It allows us to merge multiple signals on one
common transmission line. (Time-Division
Multiplexing). - Other Options and Drawbacks.
- Unipolar NRZ requires DC couples channels.
- Polar NRZ requires negative and positive voltage
supply.
126Schedule and Program Status
- Peter B. Mace
- SPACE DYNAMICS LABORATORYUtah State
UniversityUMC 4145Logan UT 84322-4145 - Phone (435) 797-0491Fax (435) 797-4044
- E-mail petemace_at_cc.usu.edu
127Program Schedule
128Radiometer Development
129Fabrication of Payload
130Software Development
131Assembly and Calibration
132Launch Schedule
133Purchasing (COTS)
134Program Status 1
- Mechanical
- Prototype layout has been developed
- Analysis and testing of prototype elements are
underway - Initial hardware has been identified and ordered
- Electronics
- Tasks have been identified
- Team members have been assigned tasks
- Board layout can be started
- Software development is underway
135Program Status 2
- Optics
- Detectors have been identified and have been
ordered - Optical elements have been identified
- Lens and filter orders pending analysis of
mechanical mounts
- Launch Schedule
- Proposed launch site
- NASA Wallops Flight FacilityWallops Island, VA
- Date dependant upon
- Number of payloads
- Science goals
136Review and Action Items
- Mr. James UlwickPrincipal Investigator
- Steward Radiance Laboratory139 The Great
RoadBedford MA 01730 - Phone (781) 275-8273Fax (781) 271-0535
- E-mail srl_at_tiac.net
- Dr. James Russell IIIPrincipal Investigator
- Center for Atmospheric SciencesHampton
UniversityHampton, VA 23668 - Phone (757) 728-6893Fax (757) 727-5090
- E-mail James.Russell_at_HamptonU.EDU