Projects/MidasBeaconReceiver/MidasBeaconReceiver/BeaconSignalProcessing

Software Radio Beacon Signal Processing

This subproject's goal is to develop a complete signal processing chain that will transform received signals from one or more satellite beacon transmitters into quantities which have useful ionospheric information. In its final form, it will use data from the Beacon Tuner subproject as input and output data to the Beacon Data Management subproject.

Beacon Signal Processing Outline

This drawing gives a general idea of the high-level signal chain flow for a typical beacon receiver.

Project Tasks

NB: Many of these items will be easier and/or necessary to obtain in a team setting! You will definitely not be doing all of this on your own. See the Beacon Team Activities page.

Step 1: Understand The Overall Task

  1. Learn required project tools (see below)

  2. Learn Wiki documentation techniques

  3. Understand basic physics and engineering behind use of orbiting satellite beacon transmitters to yield ionospheric information

  4. Understand the nature of the orbiting beacons:

    • Frequencies used

    • Satellite platforms with active beacon receivers

  5. Understand satellite orbital parameters needed in the project:

    • Data formats for satellite orbital information

    • Sources for updated satellite orbital data

    • Methods to calculate satellite position as a function of time, including set/rise/transit time relative to a ground station

    • Methods to determine relative motion of satellite from a ground receiver station

  6. Understand the nature of ground received beacon satellite transmissions:

    • Signal parameters which are useful for ionospheric measurements

    • Characteristics of a typical received satellite beacon signal

  7. Determine signal processing elements

    • Determine calculated quantities which are useful to the scientific and operational community

    • Classify received signal characteristics by type, into:

      • Systematic biases which have no ionospheric information and must be removed

      • Quantities which contain useful ionospheric information

    • Identify algorithms which will be used to process received data into calculated quantities:

      • Parameters needed for algorithm control

      • Single beacon or multiple beacon data needed?

Step 2: Design The Signal Processing Chain

  1. Write initial functional specification of signal chain, defined as complete series of steps to transform received ground signals into useful ionospheric information. Use block diagram format.

  2. Identify discrete steps in the signal chain. For each, write an applications programming interface (API) specification identifying:

    • Input data characteristics and format

    • Output data characteristics and format

    • Metadata parameters for control of processing, if any

  3. For each input or output data type, identify data class as either:

    • Persistent - data must be stored and have the capability for retrieval after the signal chain has finished calculations

    • Ephemeral - data is only needed during signal chain execution and will not be saved thereafter

  4. Identify intersection points of signal chain with other Beacon Project elements:

    • MIDAS-M Beacon Tuner

    • Software Radio Beacon Data Management

Step 3: Implement and Test

  1. Design and code in Python an initial test signal chain. Assume that data is available with signal acquisition, lock, and tracking tasks already completed.

  2. Test the initial signal chain with prerecorded GPS beacon receiver data, until results meet expectations.

  3. Design and code full implementation of signal chain functional specification, including pass prediction, signal acquisition, lock, and tracking.

  4. Test full signal chain with MIDAS-M Beacon Tuner project data.

Project Tools

last edited 2007-06-06 18:06:36 by PhilErickson