What is Space-Based ADS-B?
(Also called "Satellite-Augmented" or "Satellite-Retransmitted" ADS-B)

We call our version of Space-Based ADS-B the ADS-B Link Augmentation System, or "ALAS". With it, an aircraft can be securely tracked in real-time most anywhere on earth.

There is nothing "virtual" or "planned" about ALAS - it was the first Space-Based ADS-B system and it has been flying since 2010!

ALAS is a true over-the-horizon air traffic management system capable of delivering an uncorrupted 1090ES or UAT payload every second from virtually any ADS-B avionics system to a Surveillance System Delivery Point (SDP) in near real-time from oceanic, remote or mountainous areas where a conventional line-of-sight connection to a terrestrial ADS-B ground station is either impossible, or impractical to maintain. And the best news is that our ALAS system is flying today and the the target cost for our Space-Based system will also be less than current ADS-C services.

We feel that the increased speed and reliability of Globalstar´s new constellation, when coupled with the simplicity of our ALAS device, will far exceed the expectations of all those who have considered the option of a Space Based approach to air traffic control surveillance technology so far. The tested end-to-end system performance of the ALAS system using the Globalstar constellation is listed here:

Applicability: ALAS is a simple, light weight, low cost peripheral that works with any existing 1090ES, or UAT avionics installation. Normal air-to-ground and air-to-air ADS-B transmissions are not interrupted. ALAS is also designed to be compatible with any nation´s existing ADS-B ground infrastructure.
Coverage Area: 100% of CONUS, GOMEX, Caribbean, NAT & NOPAC by 2016 100% of remaining requirements by 2019
Availability: 99.99% by 2016, 99.999% by 2019
Capacity: >3,000 aircraft per satellite-gateway pair (approx 1,800sm diameter)
Latency: < 200ms from aircraft to ground, < 300ms end-to-end
Update Rate: 1 second
Integrity: 10E-6
Accuracy: Displayed position difference between the RF line-of-sight derived position and the Space Based ALAS derived position for the same target in the same UTC second was less than 50ft 98% of the time.
Security: UNIQUELY SECURE. ALAS establishes a unique two-way link with each aircraft that resists intrusion, jamming or spoofing and is the only form of ADS-B that can be easily encrypted. The simple tamper-proof design can also incorporate a self-powered backup system that will continue to broadcast an aircraft's position in the event of an unauthorized shutdown of the aircraft's primary ADS-B transponders
Scalability: HIGH. The relatively low cost and simplicity of the system architecture makes enhanced coverage, availability and capacity possible with the addition of more satellites and/or ground stations
Deployment: READY ALMOST IMMEDIATELY. The technology has been flight tested for more than 100 hours. Globalstar has launched 24 new Second Generation ALAS-capable satellites in the last two years. Essential Services could be deployed as early as 3Q2016 and Critical Services NLT 2019.
Cost: LOW. Buy-in and reoccurring costs for ANSP´s is minimal since ALAS requires no new satellites, or additional technology in space. It is also designed to interface easily with existing ADS-B ground infrastructure. The price point for Part 121 avionics is less than $40k and installation should be in the 20-25 MH range for most commercial aircraft.

Please try the following links for further information:

To request a complete Space-Based ADS-B Press Kit, click Here