CONAE orbit tested, verified, and implemented

1
Progress since last Algorithm Workshop

• CONAE orbit tested, verified, and implemented
• Roll, pitch, and yaw implemented
• Antenna pattern for Aquarius scale model
  implemented
• Rudimentary Thermal Model and Thermistors
  implemented
• Land Emissivity Model in progress
• There now exists fully functional (but not
  complete) and tested code for
• Radiometer Level-1a to Level 1b
• Radiometer Level-1b to Level 2
• Simplicity and readability is a major objective
  in writing source code
• Well structured (no spaghetti code)
• Thoroughly commented
• Minimize lines of code
• Have code directly relate to mathematics
• Geolocation is all done in vector notation

2
Things to Do(A partial list)

• Implement Ruf RFI flagging
• Implement other QC flags
• Further test. review, and finalize radiometer
  sensor model
• Adapt geolocation to handle of orbit-maneuvers
• Implement galactic radiation into simulation and
  L2b algorithm
• Implement solar backscatter into L2b algorithm
• For the next year, there will be continual
  updates and improvements

3
CONAE Orbit

• The simulator now uses the CONAE orbit
• Histogram shows some differences between JPL and
  CONAE mostly at the perigee. RMS difference in
  altitude within an orbit is 108m.
• Simulated Nadir Latitude, Longitude, and Altitude
  agree with CONAE to better than 250 meters
• Roll, Pitch, and Yaw are now simulated assuming
  geodetic mission

4
Scale Model Gain Pattern
5
Land Emissivity
Model

• Includes
• surface temperature and moisture from NCEP
  (simultaneous)
• Surface type (bare, ice, grass, crop, tree
  (tropical, deciduous, conifer)) from EUROCLIMAP
  monthly/annual climatology
• Soil roughness effect
• Vegetation effect
• L-band dielectric model of Dobson et al. 1985

6
TA to Voltage (count) Forward Simulation
70
1
68
2
31
37
34
3
38
30
-34
4
TND500K, TDL290K, TCND500K
7
3rd Stokes Calibration gain and offset

• Estimating Gpv, Gph, op, Gmv, Gmh, om
• 3 calibration looks are needed (used 4 looks -
  overdetermined)

• Estimating GpU (same for GmU)
• 4th calibration look (vCND) is used
• vp,earthearth count at 10milisec interval
• TCND,v and TCND,h are set to TCND/2

8
3rd Stokes Calibration gain and offset

• TU produces vp and vm signals
• Thus vp and vm are used to estimate TU
• Yet vp and vm are affected also by Tv and Th
• Manipulating the forward equation yields
• First, retrieve earth-view Tv and Th
• Then, estimate Gpv, Gph, Gmv, Gmh, GpU, GmU, op,
  om.
• Then, remove contributions of Tv and Th to vp and
  vm
• Finally, account for GpU, GmU, op, om

9
Testing TA ? Counts ? TA

• Simulates, based on ATBD (Piepmeier/Pellerano/Wils
  on/Yueh 2005)
• radiometer (Ta ? counts)
• Ta retrieval (counts ? Ta)
• Used minimum 2 calibration looks for v-/h-pol and
  4 calibration looks for 3rd Stokes
• Fully used correlated noise diodes
• Accuracy is better than 0.01K

10
End-to-End Aquarius On-Orbit Simulator Part 1
TB
Cosmic Background 2.7 K
Earth Scene Ocean Salinity,
SST, Wind fields Land Soil moisture, vegetation
type, LST Ice Ice type and temperature Atmospher
e (including limb) NCEP profiles
TB
Galaxy To be implemented
TB
Sun Year 2000 actual values
Easily scalable
TB
Faraday Rotation Actual TEC values Earth
Magnetic Field
TBrotated
Orbiting Antenna CONAE Orbit
Parameters Roll/Pitch/Yaw now included Aquarius
Scale Model patterns
Orbiting Thermal Model Simple harmonic of
orbit position
Orbit Position
TA Integration Full 4-Stokes
Integration over Earth and Space
Temperatures
TA
Radiometer Piepmeier Forward
Model for TA to counts
Thermistor Response Func. Linear
with temperature
Radiometer Counts
Thermistor Counts
11
End-to-End Aquarius On-Orbit Simulator Part 2
Radiometer Counts
Thermistor Counts
Pre-Formatter Format
in Group, Block, and Sub-Block Structure
Telemetry Formatter Format
in Group, Block, and Sub-Block Structure
Scatterometer Data
Platform Data
Simulated Downlink Telemetry
Level-0 to Level-1A Processing
Level-1A to Level-1B Processing
Antenna Temperature
Level-1B to Level-2 Processing
TOA Brightness Temperature Swath Salinity, SST,
wind, etc
Level-2 to Level-3 Processing
Time-Averaged Salinity Fields
12
Explanation of L1B Geolocation Arrays
Sun sunlat, sunlon sundis
Gain Angles Direct and Reflected
Solar tht_global_sun(2) phi_global_sun(2)
Aquarius
Boresight Reflection glxlat glxlon (J2KM)
Moon moonlat, moonlon moondis
Earth Surface
Boresight cellat cellon celinc celazm celpra
Solar Backscatter suninc sunazm sunglt
Solar Reflection refllat refllon reflinc
13
L1A_to_L2A Module (part 1)
14
L1A_to_L2A Module (part 2)
15
Source Code (example 1)
16
Source Code (example 2)
17
Source Code (example 3)
18
Source Code (example 4)
19
Source Code (example 5)
20
Source Code (example 6)
21
Source Code (example 7)
22
Source Code (example 8)
23
Include Files
24
Salinity retrieval over coastal seas (ongoing)

• APC (antenna pattern correction) coefficients are
  trained with 4?-integrated Ta

Tested on a half of orbit 1
25
Salinity retrieval over coastal seas (ongoing)
land emission corrected
with land emission
land fraction

• Can get closer to the coast by 100-200km
• Simultaneous correction of land emission over the
  coastal ocean is possible