Space Weather & Physics
Topside Sounder
Future Plans
We have designed and developed a prototype sounder under the sponsorship of ONR. The prototype needs to be adapted to specific missions and integrated with other mission elements and radio beacons to be deployed in a small, inexpensive satellite that can be quickly designed.
Several elements of the proposed topside sounder are novel. Some of the critical subsystems include:
A. Sounder Hardware
B. Sounder Software
C. System Integration Plan and Engineering Design
- A DSP-based, software-controlled sounder with a coded waveform for improved performance at low power. It is based on multiple Analog Devices AD2106X DSP processors. It also includes a complete Tx-Rx control unit.
- This sounder control unit works closely with the HF transmitter and receiver modules.
- The antenna system design uses the Numerical Electromagnetic Code (NEC). It can transmit between 2-20 MHz. For reception, it obtains the signals needed to determine angle of arrival, and matches antennas dynamically.
- The complete set of prototypes has been tested as a ground-based ionosonde.
B. Sounder Software
- We have developed an expert system and data-analysis techniques.
- We have developed a direction-finding algorithm.
- We have developed a synthetic-aperture algorithm will be developed and tested on synthetic data.
- We have developed control sequences for the sounder will be developed.
- We have tested this software on the prototypes and data acquired through them, except for the synthetic-aperture algorithm, tested on synthetic data.
C. System Integration Plan and Engineering Design
- Satellite System includes the following: other sensors, payload mass, power requirements, thermal requirements, pointing control and knowledge, on-board data reduction and compression, data storage, telemetry, command handling, interaction among sensors, redundancy and environmental issues. Much of this is determined by the selection of the appropriate satellite bus, e.g., buses made by Spectrum Astro, OSC, and Ball Aerospace.
- Launch System includes the following: launch vehicle, launch site, and certification. This will be affected by the payload, satellite bus, and desired orbit. Possibilities include Pegasus and Taurus, but consideration will not be limited to these.
- Ground Segments include the following: S-band versus X-band telemetry; one versus multiple ground stations; command structure and control; cross-links; data reduction, visualization, and archiving; and data distribution to end users.
- Operational Plan includes the following: agencies, experimental priorities, experimental plans.
