“Temporal Phase Diversity Through Modeling” was a small scale funded study to examine a key aspect of leap frog sensing technology which has the potential to dramatically reduce the cost of satellite imaging systems.  It could well be the key enabler for persistent surveillance where low earth orbit (LEO) resolution can be achieved at much higher orbit regimes like geosynchronous  (GEO) orbits. The concept of using changes in frame-to-frame phase map to calculate, predict and correct wave front error was developed as part of a broader design effort to reduce the rigidity of space remote imaging large optical systems.  The core axiom of this concept is: frame to frame phasor spin maps are essentially linear combinations of individual optical figure error modes within the “differential” tenth-lambda to quarter-lambda optical figure error range.  A detailed technical description of the core ideas of TPD is available through the contact us information at this web site.

CLOSE: Venture Ad Astra supported prime contractor Ultra Electronics - ProLogic, Inc. on this US Army funded software development project which involved tracking targets in immersive video scenes. VAA supplied systems engineering, test expertise for the project. The final report documents technical research, methods, and findings from the design and development of the Constant Look Operating System Enhancement (CLOSE) project. Findings include a survey of tracking approaches in video surveillance, with selected implementation, performance metrics, and field testing results. Also included are analyses of efforts related to the presentation of video streams, including video stitching methodologies based on 3D rendering. Finally, it is concluded that the project was an overall success, and provides a solid platform for future development.

PNET II is a currently active AFRL funded project that is based on PhaseNet technologies. PhaseNet is a network based, software centric location-timing technology which builds on Global Positioning System (GPS) theory and practice, that enables any communications network to become location aware and creates a high precision ‘network’ time.  It relies on a relatively simple time-stamping approach which has an elegance of widespread applications largely independent of communications protocol, frequency, and range.  Building on previous PhaseNet development, the goals of PNET II project are to create a more robust Clock Validation Module (CVM) and achieve pico-second scale timing and sub-meter location accuracy. PNET II is a software radio project that implements the core technologies in a standardized 915 MHz RF frequency spectrum using off the shelf commercial transceiver and a PC based architecture over a standard network to demonstrate core algorithms and their flexibility for adaptation in various hardware environments and public and proprietary RF network architectures.

PhaseNet (also branded as ZuluTime in the commercial/consumer sector) uses any wireless network as the location network PhaseNet uses the communications emanating from these devices within the network to measure the distance between the same devices/nodes. This is quite similar to how GPS works outdoors, but with each node functioning as a pseudo GPS satellite.

PhaseNet’s core algorithms work by watching clock observables of the transceivers (radios, Wi-Fi, etc.) on board the nodes within the network. PhaseNet works by exploiting two common aspects of wireless networks: 1) nodes in wireless networks pass messages to one another, and 2) each node has a local oscillator or counter which can be used to identify messages. Since it is PhaseNet and the network itself that ultimately provides the “reference time” there is no GPS or other high accuracy clock in the loop unless that is a business requirement.

• Small kernel of software and processing algorithms is at the core of the technology

• Passive, receive-only nodes accommodated.

• Surface, air, space, and cross domain networks supported

• Inherently, flexible, robust and secure

Alaska Aviation Safety Project. Automatic Dependent Surveillance – Broadcast (ADS-B) is the backbone of the FAA Next Gen Air Transportation system.[1]  ADS-B in turn, is anchored on Global Position System (GPS) derived position and velocity information.  Because of satellite based navigation (SATNAV) vulnerabilities, it is widely recognized that the future system-of systems must have a networked system wide backup.  This paper argues that the Venture Ad Astra developed Phase-Net technology is an excellent fit to make ADS-B more robust and capable.  There are several key trends and criteria which make Phase-Net an attractive backup “alternate” and allow it to provide position and velocity information to the ADS-B system during periods of GPS unavailability.

A precision timing/location technology called Phase-Net which builds on GPS and network theory and practice is currently under development and could make ADS-B tolerant of satellite based navigation disruptions.  This software based technology holds the promise of allowing ADS-B equipped systems to “ride through” periods of GPS outage with minimal degradation of system accuracy.  The attractiveness of Phase-Net in comparison to other backup systems includes the following:
 
1.  No new avionics is required which greatly simplifies the aircraft component of the system
2.  No separate ground infrastructure required
3.  Independent of and a significantly different mode of operation than GNSS
4.  Globally extensible
5.  Low cost because it highly leverages ADS-B

[1]    http://www.faa.gov/news/fact_sheets/news_story.cfm?newsId=8145, 9-25-08

For further information, please email us and request a white paper.

The ring concept depicted in the animation above can provide persistent remote sensing at a small fraction of the cost of today’s low earth orbiting full aperture systems.  The ring incorporates several unique attributes and facilitates less stringent stiffness requirements, greatly reducing cost and simplifying many design parameters.  This sparse aperture approach is also adaptable to tethered and free flying arrays in the future.

Ring Telescope reconnaissance Satellite

• Revolutionary system for a High Orbiting Imaging Satellite with Low Earth Orbit Image Quality.
• Underlying math and optics principles applicable to any segmented optics system

Ring Strategy—Building Block Approach

• Develop underlying technology incorporating hardware in the loop
  
  
• Pre-feasibility: A study of less than $1 million to define the system scope and technology. Complete in 1-2 years

• Proof of Concept – Project “Warehouse”: Assemble a ring telescope on-ground prototype, to prove the analogous value of the technology for space-based observation. We believe project “Warehouse” cost is appropriately $10-15 million, and be complete in years 3-5.

• First flight of the Ring Telescope: Attainable within years 7-10. Each telescope provides accurate coverage from a geosynchronous or highly elliptical orbit.

Funding the Development: Partnering with the U.S. Government

• The U.S. Government has interests in each step of the Ring Telescope
  development.

• VAA has received high levels of interest in Government participation /
  co-development of the Ring Telescope.