Building a new Radar Altimeter Model
by Estela Hernandez
November 24, 1997
The radar altimeter measures the altitude of an aircraft
by measuring the echo of a radio wave to return and the direction from
which it returns. The radar altimeter provides an accurate indication
of altitude of the Space Shuttle from 5,000 ft. to touchdown. We are trying
to update the Space Shuttle model to make the radar altimeter more accurate.
Currently, I am looking at the math model and trying to compare it to
our Space Shuttle simulation. This is being done at the same time as the
implementation of global positioning system (GPS). Eventually, with both
of these instruments working accurately the astronauts will have more
precise information.
The math required for the implementation of the model
is basic calculus and physics. This is how the model simulates the changes
in altitude.
The scientists are NASA employees as well as contractors
from Houston and Los Angeles. The scientists design and check the model.
Then they send us the model with their checks so we can match them with
ours. This will allow us to make sure that it is accurately modeled. This
simulation will take place in February when the astronauts will fly the
new radar altimeter model at the Vertical Motion Simulator. The astronauts
will fly approach and land usually starting at about 10,000 ft. As a simulation
engineer, one of my responsibilities is to fly the simulator to make sure
everything is working properly.
While the project is challenging it is also very
interesting. If I run into problems, there is always someone who I can
turn to for help.
