Mars Atmosphere Temperature and Humidity Sounder MATHS

1
Mars Atmosphere Temperature and Humidity Sounder
(MATHS)

• Description
• Develop sub-millimeter wave (557 GHz) up-looking
  radiometer prototype.
• Provide Martian atmospheric observations
  addressing critical questions in our
  understanding of Martian climate and volatiles
• Provide essential environmental data for design
  of future Mars Exploration Program (MEP) landers,
  rovers, and aerial platforms.

Radome
200 mm
Dimensions 200 x 100 x 75 mm
Funding Profile (K)
Technology Tasks 1.0 Instrument Design L.
Riley/386 2.0 Science Design M.
Janssen/326 3.0 Receiver Development E.
Schlecht/386 4.0 Backend Development 4.1
IF L. Riley/386 4.2 Electronics R.
Denning/386 5.0 Antenna Mechanical 5.1
Antenna L. Riley/386 5.2 Mechanical TBD/35x 6
.0 Integration Validation TBD/386
FY04-FY06 Critical Milestones FY04 System Design
Complete 5/1/04 Sub-mm Receiver
Complete 9/30/04 FY05 IF Processor Complete
4/1/05 Cal Antenna Complete 5/1/05 Mech.
Thermal Complete 5/1/05 Detector Data Sys.
Complete 8/1/05 FY06 Instrument IT Complete
3/1/06 Environmental Test Complete
6/1/06 Final Report Complete 9/30/06
2
FY04 Milestones
Blue Original schedule Red Actual and revised
schedule
3
Technical Accomplishments

• Major technical accomplishments for this
  technology area during the last quarter
• Preliminary science requirements developed
• Modifications to instrument design as proposed
• Completed optimization of the instrument system
  design
• Optimized frequency down conversion plan
• Defined critical RF component requirements
• Completed design of antenna optics
• Defined antenna optical prescription
• Defined antenna illumination and patterns
• Completed assembly and test of prototype 557 GHz
  receiver
• Collected and inventoried spare MIRO receiver
  parts
• Plated receiver bodies
• Assembled and tested receiver
• Began design of advanced MOnolithic
  MEmbrane-Diode (MOMED) 557 GHz receiver
• Began design of MATHS electronics

4
Significant Events

• MATHS profiles temperature and humidity in the
  PBL. Proposed requirements were reexamined in
  light of MER results.

• Temperature is sounded in the 576 GHz CO line
• ? 0 6 km altitude range
• ? 2- 5 K accuracy
• ? 100 m resolution at surface
• ? 5-min time scale (change from hourly)

• Water is sounded in the 557 GHz H2O line
• 0 6 km altitude range
• 30 relative K accuracy
• 100 m resolution at surface
• 5-min time scale (change from hourly)

• Reexamination led to modifications of instrument
  as proposed
• Discrete elevation stepping at fewer points to
  speed up data collection
• Consecutive rather than concurrent sampling of
  the two lines
• No time saved by concurrent sampling
• Simplifies instrument (only one channel needed
  instead of two)
• Modeling of retrieval procedure in progress
• Atmospheric dynamics model used to generate
  sample cases
• Forward calculation developed
• Retrieval algorithm outlined
• Will be used to develop detailed requirements for
  instrument

5
Significant Events

• Completed System Design Trade-off Study
• Developed optimized system architecture
• Optimized spectral design
• Analyzed LO spectral performance to minimize line
  interference
• Considered 12CO, 13CO, H216O, H217O and H218O
  lines.
• Developed simple design to minimize mass and
  power consumption
• Is key to design to meet science goals and
  performance requirements
• System design approach
• Spectral analysis of CO and H2O lines by stepping
  frequency of first local oscillator
• Double down conversion with fixed second local
  oscillator
• Switch to provide alternate measurements of CO
  and H2O lines

6
Significant Events

• Antenna design completed
• Designed antenna optical prescription
• Antenna design was carried out to meet 1.5 degree
  beam width requirement
• A electromagnetic field analysis program was use
  for simulations
• Antenna design is critical to meeting MATHS
  atmospheric measurement requirements
• Antenna characteristics
• Antenna is 31 mm aperture 90 degree offset
  parabolic reflector fed by a Pickett-Potter horn
• -30 dB edge illumination gives less than 35 dB
  first sidelobe levels

7
Significant Events

• Completed assembly and test of brassboard 557 GHz
  receiver
• Completed brassboard receiver
• Collected and inventoried MIRO receiver parts
• 557 GHz mixer body and diodes
• Frequency tripler
• 140 GHz Gunn oscillator
• Subharmonic mixer
• Got agreement from MIRO Project for use of parts
• Assembled and tested mixer
• Integrated and tested receiver
• Receiver is the most challenging component of the
  instrument
• Test results indicate adequate performance for
  breadboard instrument
• Less than 6,000 K double sideband noise
  temperature at relevant frequencies
• More than 2.3 GHz input frequency tuning range

IF Output
Input Feedhorn
Mixer
Frequency Doubler
140 GHz Gunn Oscillator
Subharmonic Mixer
System Noise Temperature 6,000K
LO Tuning Range ³ 338 MHz
8
Plans for Next Quarter

• Procure intermediate frequency components
• Complete assembly of first iteration of MOMED
  mixer
• Complete assembly and begin test of digital
  control and bias electronics
• Begin mechanical design of instrument
• Begin antenna scan mechanism design
• Begin fabrication of antenna reflector
• Procure calibration targets

9
Financial Status Obligations Cost
10
Financial Summary

• Development effort is on schedule
• Obligation of funds is at a rate lower than
  planned
• The general plan has been to focus the funding
  during the first year on development of the
  receiver.
• Receiver development using MIRO residual parts
  started late but took less time and was less
  expensive that originally predicted.
• With completion of the receiver, work is now
  beginning to focus on other aspects of the
  instrument including intermediate frequency
  components, electronics and mechanical design.
• It anticipated that an under run will occur this
  FY but that the funding will be used for more
  through test and analysis during the latter two
  years of the project.

11
Action Items/Issues/Concerns

• No previous review has taken place on this task.
• Re-plan will be carried out since receiver
  delivery is ahead of schedule.
• Intermediate frequency and electronics
  development will be accelerated.
• Mechanical development will be accelerated.
• More thorough testing will be carried out in the
  validation phase including more measurements of
  simulated Mars atmosphere