ETTC'2003 - SEE

paper or an electrostatic array using special paper. Some of these types of
recorders are also in service for certain ground-based flight test applications.
The thermal array recorder followed shortly after the electrostatic array recorder.
This printing method, still the most widely used today, has a number of benefits
including high resolution printing, high frequency response, flexible chart formats,
and alphanumeric annotation. Because of the digital nature of this technology
and the number of available interfaces, full command and control could be done
by a host system. Over the many years since the introduction of the first thermal
array recorder, features such as large memory capacities, external video display,
and digital signal processing were added to these instruments. High-speed
digital data inputs became widely used, eliminating the high costs and constant
need for calibration of digital-to-analog converters (DAC) for many flight test
installations.
The Latest Advances in Telemetry Recording Systems
The latest generation of telemetry recording systems greatly expand upon the
thermal array platform. These instruments not only perform the traditional strip
chart functions, but offer the flight test engineer a complete data collection and
review workstation. These systems offer complete customization of the data
viewing and printing and also allow the user to define the control interface. The
network connectivity and peer-to-peer capability of the telemetry recorder make it
an integrated component of a flight test facility.
Large Displays with Touch Panel Interfaces
One of the major advancements in telemetry recorders is a large real-time
display which shows the signals in a traditional waterfall format. The latest
displays are 18-inch backlit color LCD's with 1280x1024 resolution. This type of
display allows the user to see a large amount of data on the screen. Instant
waveform identification is made possible with the use of unique colors, which can
be changed based on a user-defined alarm limit. These large displays also offer
graphical templates indicating grid values and annotation, similar to the paperbased
templates that flight test engineers have used with pen-based recorders
for many years (see figure 1). XY plots are also available in some of the latest
systems.
These displays also offer the important benefit of a real-time pen emulation. In
many applications such as flutter and flight safety testing, the ability to see the
pens move is paramount. These high-resolution displays allow a realistic
simulation of an analog pen movement (see figure 1). In addition, a pen-sound
simulation can be found in some of the latest recorder designs. The visual and
audible feedback from the pen movement create a realistic equivalent to a penbased
analog strip chart recorder.