Advanced Technology Microwave Sounder ATMS

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Advanced Technology Microwave Sounder (ATMS)
For NPP Science Team Meeting November 4, 2003

• Jim Shiue
• NASA Goddard Space Flight Center, Laboratory for
  Hydrospheric Processes

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• Contents
• Background Heritage
• New features of ATMS
• Channel freq. other parameters
• Block diagram/Hardware design
• Scanner profile

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ATMS

• Heritages
• - From AMSU-A AMSU-B, HSB, NOAA-15, -16, -17,
  AQUA METOP (Eumetsat)
• Other features
• - Uses advanced technologies (e.g. LNA, MMIC) to
  reduce instrument noise, mass, power volume
• - AMSU P200 W, M160 kg, V. 1 m3
• - ATMS P 93/(110)W, M 76/(85) kg,
• V. 0.2 m3
• Predicted, as of 9/03 (xx) Allocated

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ATMS

• Other features continued
• - ATMS Vlt70(vel.)x60(nadir)x40 cm3
• - ATMS has 3 more channels than AMSU
• - better radiometric resolution (NEDT)
• - better sampling and spatial resolution (in
  temperature sounding channels)
• NASA develops the EDU PFM IPO takes over
  for FM1- FM4

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ATMS

• Other features continued
• Temperature sounding channels have 2.2o beams
  Nyquist-sampled in both along-scan down-track
  directions
• Total-power radiometer cross-track scan
  (integrate-while-slew) filters setting
  bandwidths
• Hot--cold, 2-point on-board calibration once
  every scan period (8/3 second)

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ATMS Channel Center Locations
22
21
Ch.3-15
Ch.19
Ch.18
Ch.1
2
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ATMS Channel Parameters
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ATMS Channel Parameters (continued)
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Functional Block Diagram
Receiver Subsystem
Antenna Subsystem
Electronics Subsystem
Discrete
pulse
Filter
Ch1
LNR
commands
DPLX
Ch.
1-2
Ch2
Filter
LNR
Passive
Video
analog
Digitizer
Ch 1-11
telemetry
RFE
1 Hz Time of Day Pulse
Ch.
3-15
Scan Drive Subsystem
57
GHz
SAW
Digital
PLLO
1/8 Hz Scan Sync Pulse
CH 12-15
Video
signal
Filters
processor
Redundant Spacecraft interfaces
HotTargets
Scan drive electronics
Dual
Electronics
1553B
power amp
CCA
Power
supply
PRT
Ch. 17
HKPG
PRT Data
CCA
Heater Power
Ch. 16
Ch 16-22
Video
Filters
MXR
Operational Power
DPLX
Ch. 17-22
Video
Filters
MXR
Ch. 18-22
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ATMS Instrument Design
Parabolic reflectors
Feedhorn
Upper assembly
Scan drive
Ch. 16-22
Ch. 1-15
Optical bench
Alignment cube
IF digital filter assembly
Power distribution assembly
Lower assembly
Signal processor assembly
Nadir (z)
Scan drive electronics
Antisun (y)
Velocity (x)
0800-3138
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Scan Drive Dynamics
S/C velocity out of plane of paper
1
96
Scan Pattern
(4)
Hot
C
(Hot cal.)
Sun
Cosmic background

• 18.018 ms per beam
• 96 beams 1.11 on-center
• 4 selectable cold cal positions

Cold (4)
B
Sync pulse
A
POS 96
POS 1
(48)
(48)
at location B
Nadir
Earth scene sector
0600-3335
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Scanning Characteristics
Sampling
(824 Km orbit, NPP)

• Contiguous 1.1 cells
• Nyquist for 2.2 cells

105.45
IFOV 1
17.6 km Scan spacing
16.0 km
Swath 2503 km
Sample interval
Subsatellite track direction
IFOV 96
65.7 km
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ATMS Channel Parameters (cont.)