Geospace Receiver Block Architecture
This project seeks to prototype components and approaches to enable the rapid development of scientific Geospace receivers and signal processing systems. The project will use high level tools for FPGA development and software radio techniques for signal processing and analysis.
The overall goal of the Geospace Receiver Block Architecture is to specify the high level design for a series of receiver components. These components can be individually fabricated and tested. Each type of module will have a standardized footprint and input output configuration which will allow for a flexible variety of specific implementations. The physical fabrication of all the modules will use a castellated circuit board approach that will allow fully assembled and tested modules to be integrated onto carrier circuit boards. Different modules and components can be combined into configurations tailored for specific applications. Modules will be designed to allow for coherent control relative to a stable reference oscillator and pulse per second source. This control will use a standardized serial interface and coherent pattern queues to allow for precision sequencing of operational state changes.
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Mailing ListThe prototyping effort is divided into three subprojects :
1. Wideband Radio Tuner for Geospace Science Applications
Radio signals can be used for the scientific study of the Geospace environment. A variety of signals in the HF to UHF frequency range are of great interest for passive observation and analysis. Active measurements using ionospheric radar systems are also used to study the near space environment with great detail. All of these scientific radio systems require precision radio receivers to acquire their data. This project will focus on the development of a highly integrated RF tuner for radio science applications. The tuner will support radar operation by incorporating modes of operation which enable precise control and synchronization of receiver state between multiple receivers. It will be implemented using a commercial radio chip that has very wide tuning range without the need for large physical filters. A printed circuit board (PCB) module will be fabricated, integrated into a demonstration receiver, and tested in both the lab and the field. For the field tests we will use existing instrumentation such as the Millstone Hill UHF radar system and the ISIS (Intercepted Signals for Ionospheric Science) array.
2. Advanced Digital Receiver for Distributed Instrument Arrays
The reception of radio signals using digital receivers and software radio systems is an important basis for scientific study of the near space environment. Modern digital receivers are highly complex devices implemented using configurable digital electronics, precision analog to digital converters, and embedded computing systems. It has recently become possible to produce highly integrated receivers suitable for use in low cost distributed instrument arrays. Radio receiver arrays can be used to receive a wide range of signals for scientific studies. Examples include monitoring of satellite borne radio beacons and passive radar observations using commercial FM radio broadcasts. This project will focus on the integration of a receiver system for use in such distributed instrument systems. We will implement a prototype digital receiver consisting of the hardware, firmware, and software necessary to demonstrate the reception of radio signals, data buffering and signal processing, and delivery of this information to a network interface. We will debug the prototype hardware platform and gradually implement additional functionality. Testing will be both in the laboratory and with real world signals as appropriate.
3. Adaptive Software Satellite Beacon Processor for Geospace Environmental Sensing
A number of currently orbiting satellite platforms have radio beacons which can be used with ground receivers for remote sensing of the near space environment. Traditionally, the reception and processing of beacon data has taken place within closed platform analog tracking systems which often imposes limitations on resulting spatial and temporal resolution and coverage. Modern wideband tuner and digital receiver platforms provide the opportunity to explore new and robust algorithms which adaptively process beacon signals to provide maximum observational fidelity. This project will focus on the implementation and integration of a fully software based beacon receiver, whose components include signal processing, frequency tracking, scientific analysis, and database output elements. We will debug and optimize performance of the beacon processor on a MIT Haystack software radio platform, and will demonstrate its end-to-end functionality with both synthetic and real world beacon signals as appropriate. Finally, we will gradually introduce additional adaptive enhancements to the beacon processor's tracking and filtering capabilities.