International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Overview of video compression modules developed and flown as part of PSL’s flight-proven family of modular PCM components. Wavelet based video compression deck is compatible with PCM Encoder modules, allowing video to be included in instrumentation data stream. Video compression modules allow the user to select video frame rate and video quality, supports 8-16 bits/word, and non-symmetrical PCM matrices. Video Compression and formatting is achieved with a wavelet compression IC and specialized DSP code. Video output is achieved with PSL PCM Decommutator and Video Decompression Module.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / This paper will discuss the performance of pulse code modulation (PCM)/frequency modulation (FM) during frequency selective fading. Frequency selective fading occurs when the attenuation in part of the frequency band of interest is much greater than in the rest of the band of interest. The frequency selective fading model used in this paper assumes that two paths with different delays exist between the transmitter and receiver (multipath). The two-path model was simulated in the laboratory and the effects of frequency selective fading on the radio frequency (RF) spectrum and on the waveforms at the output of the FM demodulator were measured. A mathematical model was also used to predict the effects of frequency selective fading. The predicted waveshapes are compared with the laboratory data. A simple demodulator which alleviates the effects of frequency selective fading on PCM/FM at moderate signal-to-noise ratios (SNRs) will be described. This demodulator is created by detuning the telemetry receiver by a frequency equal to approximately one-half of the intermediate frequency (IF) bandwidth and using the receiver’s amplitude modulation (AM) detector output rather than the FM detector output. The performance of this offset AM demodulator will be compared with the performance of an FM demodulator. Frequency selective fades measured in real-world environments will be also presented.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / In its simplest form an automaton can be considered a set of inputs, a process, and a set of outputs. Certainly telemetry can be thought of in this way as well. Automata theory is a cross between mathematics and computer science which considers how to precisely define the inputs, the outputs, and the process of translating the one into the other. The input to an automaton can be described using a formal grammar. Two standard bit stream encodings, PCM matrices and MIL-STD-1553, are described using grammars. An example of how a grammar can be used to decode a bit stream is given. Further, ambiguity and complexity of bit stream encodings are discussed in the context of grammars. It is thus illustrated how grammars can be used to cleanly define and decode telemetry bit streams.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / The Central Control Facility at Eglin Air Force Base has acquired full intellectual rights to a single board telemetry card with device driver and test software. This card has an integrated IRIG 106 PCM decommutator, IRIG time clock and minimal PCM simulator capability using the latest in Field Programmable Gate Array technology. Eglin will offer this capability to the telemetry community as both open source hardware and software and solicit partnerships with both government and private industry for both open source and closed source for-profit products.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Caterpillar Inc. has been testing construction and mining equipment using Computerized Analysis Vans for two decades. During our latest van upgrade, we chose to move to PCM/FM from FM/FM mainly to increase the channel count. We also replaced our old signal conditioning that used span and balance potentiometers with computer programmable signal conditioning. This new signal conditioning requires that the gain and balance point be calculated for every channel on each test. The formulas for these calculations depend on the sensor, the signal conditioning card used, and the test requirements. Due to the number and variety of machines tested at the Caterpillar Proving Grounds, these calculations needed to be automated. Using a few initial parameters and the information from our sensor calibration database, each channel’s balance point, gain, and expected slope are calculated. This system has increased productivity, accuracy, and consistency over manually calculating these parameters. This paper covers the sensor database, the calculated parameters and an overview of the way the system works.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / The emission of the telemetry signal is required over minimum two different antennas to keep the telemetry link available during a maneuver of a flying object. If nothing is made at the transmitter side, the telemetry link can be fully lost as both signals may have an opposite phase. We here propose a simple solution based on delay diversity to solve this problem. The basic idea is to introduce a delay between both emitted signals to guarantee a non-destructive signal recombination. We then exploit the ability of the blind equalizer developed by ZDS for the PCM/FM modulation to correctly equalize this signal and to recover the initial data. This solution does not require any modification of the on-board and floor set-ups except the introduction of a delay line between both transmitting antennas. It also does not need any pilot sequence and is natively robust to multipath perturbations.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / On reviewing current PCM on-board data acquisition systems design is not very uncommon to find lots of useful signals being generated together with the PCM stream, such as bit clocks, word clocks, minor and major frame pulses. The purpose of this paper is to demonstrate a conceptual design of a digital recording device that takes advantage of these signals to collect data directly into a computer compatible disk file. Such device can eliminate the need of further PCM signal processing after the test and speed up the conversion process of pure digital sampling values into floating point numbers.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The bit rates of telemetry systems are increasing rapidly. Higher bit rates occupy more spectra and result in decreased link margin. The major signal parameters that affect the spectral occupancy and bit error probability (BEP) of binary pulse code modulation (PCM)/frequency modulation (FM) signals are the bit rate, code, premodulation filter, and peak deviation. The measured spectral occupancy is also affected by the spectrum analyzer (or other measurement equipment) settings. Additional parameters that affect the BEP include the receiver intermediate frequency (IF) filter, the FM demodulator, and the bit detector. This paper will present the effects of these parameters on the measured 99% and -60 dBc bandwidths and the BEP of binary PCM/FM telemetry signals. Normalized BEP and bandwidth curves will be presented.

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Low cost recording devices for telemetry and other data acquisition applications are of vital importance in light of today's shrinking budgets and project cut-backs. The desire to replace large, expensive, multi-channel recorders with smaller, less expensive recorders is becoming commonplace in government and industry. Many of these small recorders in the past have been limited to a single recording channel, and to one particular data type, due to recorder architectures. The 8 millimeter (8mm) tape cartridge recorder has been looked at in the past as a low cost recording device, however products utilizing this technology have been strictly limited in the number of channels, and data types. In response to this need, Veda has developed a new data acquisition recorder utilizing an 8mm recorder packaged in a small, flight qualified rugged enclosure with modular, and interchangeable, input channels. These microprocessor controlled inputs are capable of accepting PCM telemetry, MIL-STD-1553, voice, IRIG time, and ARINC 429/629 data. The new architecture allows for multiplexing of multiple channels onto the single channel tape medium as well as direct playback from the recorder for certain data types. This paper will discuss the recorder's architecture, design problems solved during development, and general capabilities.

ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / Modern test programs require an increase in sensor and bus data while at the same time seeking a decrease in the size and price of data acquisition components. Data archiving, which has been traditionally supplied via dedicated standalone hardware, is not exempt to this demand, but in many ways has not kept up with other instrumentation components in terms of flexibility, size, density and price. The archiving capabilities of a data acquisition system must be able to meet the changing needs of the customer. This paper presents a Solid State Drive (SSD) based data recorder implementation that can be easily reconfigured to address the requirements of different applications, including traditional PCM based systems and contemporary network based systems. The paper identifies the requirements, design challenges, trade-offs and risks in creating a low-cost, flexible data archiving subsystem that can be used in a standalone configuration or be directly integrated with a host data acquisition system.