Air Force Satellite Control Network

About: Air Force Satellite Control Network is a research topic. Over the lifetime, 32 publications have been published within this topic receiving 201 citations.

Transmit receive module for S-band electronically scanned antenna with on board digital control, health monitoring and telemetry

Abstract: Satellites require timely tracking, telemetry, and command (TT&C) for payload operation. The ground antenna is one of the key elements that enable satellite control and payload operations. To support the operation of a large number of satellites at various orbits, operators need a network of antennas distributed around the globe, such as the air force satellite control network (AFSCN), to contact satellites at a predetermined time and location. Currently, they use large mechanically steered parabolic dishes to provide hemispherical coverage and simultaneous transmit (Tx) and receive (Rx) capabilities in support of Department of Defense (DoD) satellite operations (SATOPS) network designers used reflector antennas because of relatively low acquisition cost. The current reflector antennas used to support satellite operations are approximately 10 m in diameter and are susceptible to single point failure and long downtime for repair and maintenance. S-Band component technology provided by the cell phone industry allows an affordable electronically scanned antenna (ESA). Current SATOPS require a more efficient and flexible antenna system. The ESA can offer superior performance, operability, adaptability and maintainability for satellite operation. This paper presents the design of a TR module that can provide one transmit (Tx) and two receive (Rx) links to a satellite. The TR module is part of a dome shaped antenna that could provide multiple simultaneous ground to satellite links. This geodome antenna provide multiples simultaneous operations with pointing and acquisition taking seconds. One dome antenna can replace the capability of three AFSCN parabolic dishes. The next generation low cost TR module developed by the AFRL/Information Grid Division (IFG) and Princeton Microwave Technology Inc. for the next generation of the AF Satellite Control Network (AFSCN). The TR module differs from previous modules in Ref S.S. Bharj et al, (2000) and P.J. Oleski et al, (2004) in that it consists of a single Tx channel capable of 33 dBm of output power and two Rx channels with a gain of 30 dB per channel In addition, beam switching and on board digital control has been implemented where the Tx and Rx channels provide four-bit phase shift. In addition to the control functions, built-in test (BIT) circuits monitors the health and status of the RF devices. This function utilizes a low-power micro-controller to output digital data for each of the power and low noise amplifiers, via A/D converters. The bandwidth of the TR module has been designed to cover both the unified S-Band (USB) and satellite ground link subsystem (SGLS). The TR functions are combined at the output via a ceramic resonator diplexer comprised of a band pass-band stop filter. The control of the TR module is conducted via a single programmable logic device (PLD) controller through a DAQ computer interface. The TR module has been designed to meet the cost objective for a dome antenna with approximately 47,000 TR modules. A Td generation 78 element triangular panel of TR modules is now planned to be developed, leveraging off lessons learned from generation one. This paper describes the layout and design of the 2nd generation TR module

Air Force Satellite Control Network Review

Abstract: It is fully demonstrated fron the several local area wars in recent years that the military aerospace system is of great importance. Almost military spacecrafts in American are supported by Air Force Satellite Control Network(AFSCN) which is the most important and largest military TTC facility. The configuration, upgrades and future development trends of AFSCN are included in this paper.

Managed intelligent deconfliction and scheduling for satellite communication

Abstract: The Air Force Satellite Control Network (AFSCN) coordinates hundreds of satellite communication requests from various users every day. Building a conflict-free schedule from a large set of satellite communication requests is a difficult problem. Human schedulers are very adept at generating high-quality solutions, usually allowing all requests to be serviced. However, this process is time-intensive and requires highly trained, experienced individuals. That is, the teams of highly trained and experienced schedulers must manually check every schedule request received. Approximately half of all requests require adjustment to remove conflicts. The US Air Force (USAF) had an interest in further automating this process. Stottler Henke worked with the USAF to develop the Managed Intelligent Deconfliction and Scheduling (MIDAS) solution, an artificial intelligence (AI) tool for automatically scheduling satellite contacts, by incorporating the experience, insights, and expertise of human schedulers. MIDAS can now automate virtually all the scheduling of the satellite communication requests for the AFSCN, allowing schedulers to apply their expertise where it is really needed. MIDAS accomplishes this with a two-stage process that first shuffles tasks within their defined constraints before carefully applying a user-definable set of business rules that allow certain constraints to be relaxed when necessary. The system provides a familiar, user-friendly interface modeled on legacy Electronic Schedule Dissemination (ESD) systems to facilitate comparison and to allow users to switch from one interface to the other with relative ease. It runs on inexpensive consumer hardware and communicates with legacy systems via a well-defined plain-text file format: raw scheduling requests are imported to MIDAS, and scheduling results can be exported back to legacy tools. MIDAS now provides Air Force planning at a level not previously possible. A viable schedule can be assembled in a matter of minutes in order to assess the impact of possible outages, events, expansion of equipment, etc., that is, MIDAS provides the ability to perform “what-if” scenarios to assess the impact of a potential event or mission change. With only a few minutes of processing, MIDAS is able to deconflict all or virtually all communications requests for a given day. MIDAS has eliminated much of the repetitive work involved in scheduling and allows schedulers to focus on other important problems. This paper provides a history of MIDAS, an overview of its architecture and the many benefits MIDAS provides; in addition to its general applicability to non-USAF satellite communications scheduling.

Near term approach to data relay for satellites under test

Abstract: The increasing need for a continuous communications link with U.S. Department of Defense (DoD) spacecraft during test missions in low Earth orbit (LEG) has resulted in greater interest in geosynchronous data relay services. This may be a more economical alternative to building additional remote tracking stations for the Air Force Satellite Control Network (AFSCN), and avoids tying up operational assets for a test mission. A low-cost near-term approach for such a space-based data relay system would utilize two existing Defense Satellite Communication System III spacecraft, two existing ground terminals, and a small, standardized terminal using autonomous antenna pointing for the space vehicle under test. Such a system design is presented. >

The range scheduling aid

Abstract: The Air Force Space Command schedules telemetry, tracking and control activities across the Air Force Satellite Control network. The Range Scheduling Aid (RSA) is a rapid prototype combining a user-friendly, portable, graphical interface with a sophisticated object-oriented database. The RSA has been a rapid prototyping effort whose purpose is to elucidate and define suitable technology for enhancing the performance of the range schedulers. Designing a system to assist schedulers in their task and using their current techniques as well as enhancements enabled by an electronic environment, has created a continuously developing model that will serve as a standard for future range scheduling systems. The RSA system is easy to use, easily ported between platforms, fast, and provides a set of tools for the scheduler that substantially increases his productivity.