International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / In support of the various programs that the Phillips Laboratory's Space Experiments Directorate is conducting for the Ballistic Missile Defense Organization (BMDO), the Range Operations Division is developing a mobile telemetry processing system as part of the Mobile Ground Telemetry Station (MGTS) program. The MGTS program's goals are to develop a mission-dedicated telemetry system to supplement current test range capabilities by receiving, processing and recording multiple data streams, sometimes exceeding 10 Mbps. The system will support airborne and suborbital vehicles as well as customized satellite downlinks designed for spacecraft bus State-of-Health monitoring and sensor payload observations. Autonomy and off-road capabilities are also important factors since some of the operations envisioned require deployment to remote field locations where no telemetry processing capabilities currently exist to support the unique data handling requirements. The Phillips Laboratory has completed, with support from Wyle Laboratories and Systems Engineering and Management Company (SEMCO), a "proof-of-concept" mobile telemetry processing system referred to as MGTS #2. Demonstration of the system has been accomplished with the successful deployment and operational support provided to both BMDO's Lightweight Exo-Atmospheric Projectile (LEAP) sub-orbital missions and Miniature Sensor Technology Integration (MSTI) satellite program. MGTS #2 has deployed and is scheduled for further deployment to various operating sites including: White Sands Missile Range (WSMR), NM; Air Force Flight Test Center (AFFTC), Edwards AFB, CA; Vandenberg AFB, CA; and NASA's Wallops Island Flight Facility, VA. While deployed MGTS #2 processes, records and rapidly distributes the critical mission telemetry data conforming to both IRIG and SGLS standards. This paper will describe the evolution of the MGTS program, current hardware configurations and the various mission scenarios that have been supported by the MGTS team.

Thesis (M.S.)--Ohio University, March, 1993. / Title from PDF t.p.

No description available.

This report summarizes the design of a DME (Distance Measuring Equipment) simulator to be used in the testing of an Area Navigation System. The purpose of the simulator is to generate a signal representing an aircraft's distance from a ground station. This information is in the form of two pulses whose separation represents that elapsed transmission time for an aircraft to receive a reply from the ground station to an interrogation by the aircraft. The pulse spacing must be selectable as fixed distances for static tests and as distance changing at a constant rate to simulate flying to or from the station for dynamic testing. Thumbwheel switches are used to input fixed distances and up/down counters provide inbound and outbound range rates. The rate clock is derived from a crystal oscillator whose output is divided down by a programmable, modulo-n, divider to the desired rate/frequency. This input distance information, available in parallel binary coded decimal format, is then converted to the required pulse pair spacing. This is accomplished with presettable down counters clocked by another crystal oscillator whose frequency represents two-way propagation time for radio waves.

This report summarizes the design of a digital frequency synthesizer for airborne distance measuring equipment. It is the purpose of the frequency synthesizer to provide a stable frequency source for the local oscillator of the airborne receiver and for the power amplifiers in the transmitter chain. The synthesizer is required to furnish a frequency ranging from 260.250 mHz to 287.50 mHz in channel steps of 250 kHz at a power level of +7.0 dBm. the stability of the frequency must be greater than .005% over the temperature range of from minus 45 degrees centigrade to plus 55 degrees centigrade, requiring a crystal controlled source. Digital techniques are employed using two crystal controlled oscillators to synthesize all required channel frequencies. Linear circuits using standard configurations are employed for the oscillators, buffers, and mixers. Primary attention is paid to optimizing the transient characteristics of the synthesizer which employ programmable digital counters to change the division ratio in a phase locked loop. Decoding is provided to interface the modulus of the counters with the aircraft cockpit controls.

The key goal in this work is to enable a flexible ground station that is not constrained to a particular mission or set of hardware. In addition, with the concepts and software produced in this thesis, it will play a significant role in educating engineers and students by providing critical infrastructure and a sandbox for ground station operations. Key pieces of software were developed in this work to create a flexible and robust software-defined ground station. Several digital transmission modes were developed in order to allow communication between the ground station and common amateur radio CubeSats and SmallSats. In order to handle distributed tasks and process at a ground station with multiple servers and controllers, a specialized actor framework was written in Python for ease of use. Actors have the ability to send messages to one another over a network, and they maintain their own memory in order to avoid synchronization problems that come with sharing memory. In addition to the software developed in this work, a novel Peer-to-Peer (P2P) protocol for a network of ground stations is proposed in order to increase coverage and access to spacecraft without requiring centralized server infrastructure. This protocol provides the method to scale the developed software architecture beyond a single ground station. Since the Virginia Tech Ground Station (VTGS) will have many concurrent processes running across multiple servers, it was necessary to apply the actor model in order to simplify the design of the system. The purpose of this thesis is to describe the developed software for the VTGS as well as the P2P protocol for a larger network of ground stations. There are three primary repositories: planck-dsp, gr-vtgs, and pystation. The planck-dsp library and gr-vtgs Out-of-tree (OOT) make up the primary digital signal processing and communications toolboxes, where GNU Radio serves as the scheduler for signal processing blocks used in flow graphs. The pystation module is the extensible software actor framework that connects various systems both locally and remotely. It is also responsible for scheduling and handling ground station requests. While the software was primarily created for the VTGS, it is general enough to apply to other ground station implementations. / Master of Science

For a successful CubeSat mission, it is imperative to schedule events in a fashion that will generate maximum useful science data. Intuitive uplink commanding software is required for the Lower Atmosphere/Ionosphere Coupling Experiment (LAICE) CubeSat to ensure best results. The ground station up-link software is created with this aim in mind. This will make the operation center for the LAICE project efficient. This will also help in evaluating the effect of a particular schedule on LAICE instrument interface board (LIIB) before sending the commands to it. The interactive User Interface (UI) that makes the entire process intuitive guides the user to create an uplink schedule without any human error. The control software creates the command sequence taking in to account all the limitations and specification of the systems and instruments on LAICE. These data are backed up in an efficient format in Virginia Tech’s database for future processing. This web-based application ensures a smooth scheduling process without any errors. Assistive flight-ready software is provided on the flight computer on the LAICE CubeSat to upload the correct uplink sequence to the LIIB. / Master of Science

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / As more satellite ground station systems use the Internet as a means of connectivity, the security of the ground stations and data transferred between stations becomes a growing concern. Possible solutions include software-level password authentication, link encryption, IP filtering, and several others. Many of these methods are being implemented in many different applications. SSH (Secure Shell) tunneling is one specific method that ensures a highly encrypted data link between computers on the Internet. It is used every day by individuals and organizations that want to ensure the security of the data they are transferring over the Internet. This paper describes the security requirements of a specific example of a ground station network, how SSH can be implemented into the existing system, software configuration, and operational testing of the revised ground network.

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / There are many challenging aspects to processing data from a modern high-performance data acquisition system. The sheer diversity of data formats and protocols makes it very difficult to create a data processing application that can properly decode and display all types of data. Many different tools need to be harnessed to process and display all types of data. Each type of data needs to be displayed on the correct type of display. In particular, it is very hard to synchronize the display of different types of data. This tends to be an error prone, complex and very time-consuming process. This paper discusses a solution to the problem of decoding and displaying many different types of data in the same system. This solution is based on the concept of a linked network of data processing nodes. Each node performs a particular task in the data decoding and/or analysis process. By chaining these nodes together in the proper sequence, we can define a complex decoder from a set of simple building blocks. This greatly increases the flexibility of the data visualization system while allowing for extensive code reuse.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / The X-33 program requires the use of multiple telemetry ground stations to provide continuous coverage of the launch, ascent, re-entry and approach phases for flights from Edwards AFB, California, to landings at Dugway Proving Grounds, Utah, and Malmstrom AFB, Montana. This paper will discuss the X-33 telemetry requirements and design, including information on the fixed and mobile telemetry systems, automated best source selection system, processing/display support for range safety officers (RSO) and range engineers, and comparison of real-time data with simulated data using the Dynamic Ground Station Analysis model. Due to the use of multiple ground stations and short duration flights, the goal throughout the X-33 missions is to automatically provide the best telemetry source for critical vehicle performance monitoring. The X-33 program was initiated by National Aeronautics and Space Administration (NASA) Cooperative Agreement No. NCC8-115 with Lockheed Martin Skunk Works (LMSW).