# Presentation: 763291

## Adaptive Ground Antenna Arrays for Low Earth Orbiting Satellites
ISD Technology Workshop    Jan 24, 2005

- ISD Technology Workshop    Jan 24, 2005

- PI:     Dan Mandl/GSFC/Code 584
- Co-I:  Dr. Mary Ann Ingram/Georgia Tech
- Co-I:  Dr. Felix Miranda, Dr. Richard Lee, Dr. Robert Romanofsky, Dr. Afroz Zaman/GRC
- Partner:  Dr. John Langley/Saquish Group

## Goals, Objectives, Benefits

- Enable fabrication of cost effective antenna system for low earth orbiting satellites that act like wireless access points
- Enable sensor webs

## Vision to for Future Satellite Connectivity

**Build satellite “Hot Spots”**

**Flight**
**SW Bus**

**Ground SW Bus**

**Flight**
**SW Bus**

**Flight**
**SW Bus**

**Hot-Loadable**
**Flight SW**
**Components**

**Mission Critical Dynamic SW Bus**

**Non-Critical Dynamic SW Bus**

**New Mission Paradigm:  Flight and ground plug and play components connected with wireless access points**

## Adaptive Array Antennas Capabilities

***Antenna patterns adjusted electronically thousands of times per second to follow users and avoid interference***
***Array can be built out of phased array elements or conventional antenna elements***
***Capability for multiple access on a single channel***
***Data rates vary  per link according to the configuration of the adaptive array***

- Antenna directional sensitivity

## Related SensorWeb TasksUsing EO-1 as a Testbed

*Related SensorWeb Tasks**Using EO-1 as a Testbed*

*On-board Processing*

*End-to-End Communications*

*Autonomous Coordination*

*Operational Testbed*

***On-board Cloud***
***Cover Detection Validation***
***(complete)***

***Hyperspectral Compression WG***
***On-board data mining***
***On-board intelligent image compression***
***Working group***

***      ******Smart Antenna***
***Ground phased array***
***“******Cell tower” com to sat              ***

*** ******Livingstone On-board Model Based Diag Tool***
***Autonomous anomaly diagnosis and recommendations***

***Autonomous Sciencecraft Experiment(ASE) ***
***Onboard planning***
***Onboard science processing***
***Autonomous/event driven processing     ***

***Science Goal Monitor(SGM)***
***Semi-autonomous coordination of imaging ***

***   ******EO-1 Sensor Web demos***
***MODIS trigger EO-1 fire & volcano images***
***SGM/ASE coordinates images autonomously***
***R/T GOES cloud screening***

***Intelligent Distributed Spacecraft Technology Testbed***

***EO-1/ Gnd instr Sensor Web***
***Tiltmeters at Kilauea/Mauna Loa trigger EO-1 image***

***         ******Preliminary EO-1 Autonomy Experiment***
***On-board planning***
***On-board feature detection***
***Dynamic SW Bus***
***                     ******(complete)***
***                        ***

***Funded by ESTO***

***Funded by NMP***

***Funded by IS***

***Proposed activity***

***EO-1 Volcano Sensor Web campaign***

***Earth Phenomena Observing System (EPOS)***
***(planning system)***

##  A Proposal for a Lunar Adaptation

**Radome**

***Mechanical support***

**Multilayer Lens antenna array**

- Detail on multi-layer space-fed lens array

- Digital
- Control

- Feed side

- Non Feed side

- Circular tapered slot antenna

## Accomplishments and Planned Activities

- Adaptive Combining

- Use 2- 4 mechanically steered small dishes to capture X-Band data from SAC-C (planned March 2004)

- Use 2 – 4 electronically steered antenna elements to capture X-Band data from SAC-C(planned Fall 2005)

- Adaptive Combining

- April 7, 2004  Successfully captured S-band data from EO-1, no steering

## SRS Inflatable Apertures to be Used for March 2005 Demo

## Mechanical Steering Demo

- Use SRS’s inflatable apertures mounted on positioner
- Will use this system to capture 6 Mbps data from SAC-C in March 2005

- GRC positioner

## Electronic Steering Demo

- Platform doesn’t move
- Az/El control signals command beam directions
- Phased arrays will be calibrated
- Planned demo in Fall 2005 with SAC-C

## Steering Control Illustrations

- az/el commands

**Radome**

***Mechanical support***

**Radome**

***Mechanical support***

- Digital
- Control
- Interface

- Steering
- Control
- Computer

- Digital
- Control
- Interface

- az/el commands

- Steering
- Control
- Computer

- Digital
- Control
- Interface

## Future Implications

- Presently NASA Ground Network has spent about $2 – 4 million for each of the 11 meter antennas it uses
- Usually resides in harsh climate
- Mechanical drives decrease reliability
- Not flexible
- New technology can enable implementation of antenna systems as wireless access points
- No moving parts
- Support for multiple satellites
- Flexible, software control
- Potential to reduce cost by order of magnitude over presently used 11 meter dishes
- Can enable internet type of connectivity thus facilitate new mission operations paradigm