IEEE - Aerospace and Electronic Systems - May 2022 - 45

Rymer and Rice
Figure 10.
Project Engineer Station for the third-generation RTPS system at NATC-Pax River. Courtesy of the U.S. Navy Patuxent River, MD, Telemetry
Data Systems Department, 2003.
RTPS LEGACY
Starting with the first tests in 1973, RTPS averaged over
1200 flight operations per year using the original hardware
and software. Real-time correlation with space-positioning
( " range " ) data was added in the mid-1970s. Replication of
hardware (to handle multiple concurrent unrelated tests)
expanded from two concurrent tests in 1973 to four in 1976
and later to ten. By the 1990s more than 25,000 test operations
(flights) had been completed using the same baseline
features. Advancements during the decades after 1973
included orders of the magnitude faster computation hardware
[21], embedded microprocessors [22], [23], newer and
less expensive graphics displays, radically greater storage
capacities, and higher bit rate telemetry transmission.
While new generations ofprocessing hardware emerged,
the original precedent-setting methods and " rules " for RTPS
development were retained. Prominent among those was that
every generation ofRTPS provided, as a standard feature, the
ability to perform the preprocessing tasks and output of data
to all output devices without writing a single line of new
code. This feature was a major breakthrough when first used
on an active aircraft test in March 1973 and was not present
in the Grumman ATS [7], [24]. The capability is a significant
productivity and response feature for real-time aerospace testing
to this day. That ability to perform the preprocessing tasks
and output data to the customers with no new software is critical
to a test center's ability to respond immediately for new
test aircraft.
One of the more innovative legacies ofthe RTPS system
was the use ofreal-time telemetered data in parallel with simulated
data ofthe same measurements on the same aircraft in
one place observed by the same flight test engineers [25].
MAY 2022
This configuration involved a large simulation facility tied
into the RTPS for the side-by-side displays.
Systems with capabilities similar to RTPS were fielded
at other test ranges. Of note are the Integrated Flight Data
Analysis System (IFDAPS) [19], [26], [27] installed at the
Air Force Flight Test Center, Edwards AFB, CA, and the
Telemetry Integrated Processing System (TIPS) [19], [28]
installed at Vandenberg AFB, CA. IFDAPS was an updated
copy ofGrumman ATS and, like the ATS, proved difficult
to program and configure [27]. On the other hand, TIPS
had more in common with the third-generation RTPS system
[19].
Other software used in real-time processing (such
as that for computing derived variables, variables not
directly instrumented, but rather combinations calculated
from directly measured data) was termed " Applications
Software. " Applications Software was often created
uniquely for each aircraft or aircraft type but was also
greatly accelerated via standard interfaces with the permanent
multigenerational feature of EU converted data.
Examples of Applications Software in this context have
included center of gravity computation, which varies with
fuel usage, landing gear loads computed as results of a
family of differential equations, structural forces, weight
of fuel remaining, electrical loads, net available thrust,
performance of subsystems added to an aircraft, and
nearly endless varieties of project needs.
It should be noted that the efficiency of real-time
telemetry processing described is possible only when test
vehicle instrumentation conforms to standards [29]. Transducer
calibrations and transmission format descriptions
must be stored in telemetry processing systems to perform
real-time processing. The most used such standards
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