Demonstration of an Airborne Software Reprogrammable Payload

1
Demonstration of an Airborne Software
Reprogrammable Payload

• Ryan Hauer, Naval Research Laboratory
• Thomas Pickard, Naval Research Laboratory
• Timothy Meehan, Vista Research, formerly Naval
  Research Laboratory
• Christopher Huffine, Naval Research Laboratory

2
Outline

• Introduction
• Hardware
• Software
• Airborne Demonstration
• Results

3
Introduction

• An airborne Software Defined Radio (SDR) can be
  referred to as a Software Reprogrammable Payload
  (SRP)
• SRPs can facilitate beyond line-of-sight (BLOS)
  communication
• SRPs may allow for Automatic Identification
  System (AIS) message collection from the sky
• Demonstrate SRP with multiple applications on an
  airborne platform using COTS components
• Utilized GNU Radio, an SDR API
• Leveraged Ettus Researchs Universal Software
  Radio Peripheral and applicable daughterboards

4
Hardware
5
Software Overview

• Three major applications
• Bent pipe relay with interference mitigation
• AIS collection and downlink
• IP Router
• All software was written in Python and all
  applications which required interaction with the
  USRP utilized the GNU Radio API

6
Relay with Interference Mitigation
Signal without interference
Signal of Interest
Interference
7
Relay Application
8
AIS Application
9
AIS Application
10
IP Router
Transmitting at Frequency B
Radio 2 Receives Frequency B
Radio 3 Receives Frequency C
Radio 1 Sending to Radio 2 at Frequency A
Radio 4 Receives Frequency D
11
IP Router
12
Airborne Demonstration
The SRP hardware in a rack inside a Cessna 337
Super Skymaster.
Thomas Pickard, Ryan Hauer, and Gordon Seuell
pictured with the Cessna 337 Super Skymaster at
Indian Head Airport in Md.
13
Results

• Relay worked well out to 10 miles
• Interference was consistently mitigated
• Limiting factors included geometry, antenna
  separation, full duplex
• In the AIS application, 174 unique MMSI numbers
  were detected during one flight. Vessels could be
  observed in the Atlantic Ocean, on the Delaware
  River, in the Chesapeake Bay, and on the Potomac
  River
• Routing successfully demonstrated through chat
  program, improved performance through chats
  acknowledgement scheme

14
Conclusion

• The STAFE program demonstrated the utility of the
  SRP for military communications and signal
  collection
• The program exercised a single payload built
  from commercial components with three diverse
  applications
• In the future, robust coding techniques and
  alternative antenna designs and placement can be
  utilized to improve link performance

15
References

• 1 J. Mitola, The Software Radio Architecture,
  IEEE Communications Magazine, vol. 33, no. 5, May
  1995.
• 2 Automatic Identification System Overview
  USCG Navigation Center, United States Coast
  Guard. June 6, 2009 lthttp//www.navcen.uscg.gov/en
  av/AIS/default.htmgt
• 3 GNU Radio. GNU Radio Website. June 10, 2009
  lthttp//GNU Radio.org/tracgt