Antenna Power Switching and
Monitoring Subsystem (APSM) |
The Antenna Power
Switching and Monitoring Subsystem
(APSM) 3.1.1.1. is part of the Antenna Subassembly
(ASA) 3.1.1.1. on the ASAR Instrument |
Antenna Services Subsystem (ASS) |
The Antenna Services
Subsystem (ASS) 3.1.1.1. is part of the
Antenna Subassembly
(ASA) 3.1.1.1. on the ASAR Instrument |
Antenna Subassembly (ASA) |
The Antenna Subassembly
(ASA) 3.1.1.1. is one of the two functional
groups of the ASAR Instrument 3.1. . (
CESA is the other ) |
Calibration Loop |
The instrument
calibration loop is used to perform
three distinct functions.
Firstly, it is used to characterise the
instrument transfer function during the
measurement modes. Secondly, it is
used to characterise individual T/R
modules. Finally, it is used in the
special external characterisation mode.
( See the section entitled "ASAR
Characterisation and
Calibration" 2.11. in chapter 2) |
Carbon Fibre Reinforced
Plastic (CFRP) |
A very stiff, and
lightweight material with negligible
thermal expansion coefficient |
Control Electronics
Sub-Assembly (CESA) |
The Control
Electronics Sub-Assembly (CESA) 3.1.1.2.
is one of the two functional groups of
the ASAR
Instrument 3.1. . ( ASA is the other ) |
Control Subsystem (CSS) |
The Control Subsystem
(CSS) 3.1.1.2. drives the ASAR instrument by
providing the command and control
interface to the spacecraft, maintaining
the database, managing the
distribution of the operation
parameters, and generating the
time-lining of the instrument. |
External Calibration |
Absolute gain
calibration of the ASAR using ground
calibration transponders. ( see "ASAR
Characterisation and
Calibration" 2.11. and "Auxiliary Data
Sets for Level 1B
Processing" in chapter 2). |
External Characterisation |
Acalibration scheme
used by ASAR that involves sending a
series of pulses that are detected both
by the internal calibration loop
and the receiver embedded in the ground
transponder. Used to monitor the passive
part of the antenna, the calibration
loop and the mechanical pointing of the
antenna. ( see "ASAR
Characterisation and
Calibration" 2.11. and "Auxiliary Data
Sets for Level 1B
Processing" in chapter 2). |
Instrument ( or Internal ) Calibration |
A calibration scheme
with the objective to derive the ASAR
instrument internal path
transfer function, and to perform noise
calibration. This objective is realised
by dedicated calibration signal paths
and special calibration pulses
within the instrument for making the
required calibration measurements and by
using these measurements to perform
corrections within the ground processor.
( see "ASAR
Characterisation and
Calibration" 2.11. and "Auxiliary Data
Sets for Level 1B
Processing" in chapter 2). |
Receiver Gain Droop |
During the receive or
echo window the gain droops by up to
0.9dB. The effect has been well
characterized preflight and will be
automatically corrected in the processor. |
Tile Control Interface Unit (TCIU) |
Mechanism in the Tile
Subsystem (TSS) used to control the
individual transmit/receive
modules (TRM) of the ASA Subsystem in the
ASAR Instrument. |
Transmitter/Receiver Polarisation |
The polarisation modes
handled by ASAR's Active Phased Array Antenna. |