User's Manual

THALES COMMUNICATIONS
OIM
AHV1600-SYSTEM
Page 3
July 16/09
in the beat signal spectrum provides an accurate height measurement, and a
T
ST
for the feedback loop to
keep
fbo
in its defined frequency range from one measurement to the other. Hence the relationship :
Ho K fbo
=
. where
F
Tc
K
ST
∆
=
.
2
.
3. BUILT IN TEST FUNCTION
The AHV1600 Transceiver implements an operational built-in test (BIT) in the following steps:
A. POWER-UP BUILT IN TEST (PBIT)
The AHV1600 Transceiver is capable of carrying out a performance test upon completion of the ini-
tialization sequence after power up to confirm the serviceability of the assembly. This test is per-
formed in 3 s.
B. INITIATED BUILT IN TEST (IBIT)
The AHV1600 Transceiver is capable of carrying out a performance test to confirm the serviceability
of the Transceiver upon receipt of the discrete input signal “FCT_TST“. This test is performed in 3s.
C. CONTINUOUS BUILT IN TEST (CBIT)
The AHV1600 Transceiver is carrying out a continuous test of performance of the system as a back-
ground task. Continuous BIT provides coverage to the minimum extent possible without interfering
with the normal Transceiver operation.
The BIT is controlled by the software embedded by the equipment.
4. AIRCRAFT INTERFACE
The AHV1600 transceiver interfaces with the following equipment :
−
Airborne navigation computer,
−
Airborne power supply,
−
Two antennae.
The figure 1 shows a block diagram of the AHV1600 radar altimeter system: