Inside GNSS Media & Research

MAY-JUN 2018

Issue link:

Contents of this Issue


Page 39 of 67

40 Inside GNSS M A Y / J U N E 2 0 1 8 GRICAS designed to maximize the perfor- mances of the MEOSAR system. • It integrates an internal Galileo com- patible GNSS receiver that is contin- uously turned on: ■ to provide a source of localiza- tion, independent from any other aircra systems ■ to be able to receive any Galileo Return Link messages ■ to be able to identify spoofing or jamming attempts on the GNSS signal • During normal f light conditions, the ELT(DT) is armed and monitors information ■ From a beacon activation logic t hat computes t he automatic triggers based on detection of a distress situation ■ From the Galileo navigation sig- nal to identify a RLM with its ID encoded and to process the RLM as appropriate (activation for example) ■ From the avionics: the position provided by the avionics GNSS receiver to encode it in the dis- tress or cancellation message when the beacon is activated • It starts transmitting within five sec- onds upon reception of triggering command (either manual, automat- ic or from a remote RLM activation command) • It is powered by the aircraft main p ower bu s a nd by a n i nter na l rechargeable battery. This double power supply source enables the ELT(DT) to continue to operate when there is a total loss of power onboard and for the whole remain- ing flight (up to 24 hours). e. A fully independent solution for distress delivery in all situations e operational concept and the solution design proposed by GRICAS ensures the ELT(DT) mission not be affected by a communication link inhibition with the avionics, a loss of communication with the aircra's GNSS receiver, or even a GNSS jamming or spoofing in the vicin- ity of the aircra. Finally, the ELT(DT) can be trig- gered in a completely independent pro- cess without any inhibition risk thanks to the manual remote activation from ground by Return-Link Message. is service could be provided to airlines, which will be able to request a remote activation (and deactivation) to the Return-Link Service Provider, knowing that the activation of the ELT(DT) will set off a distress at the RCC responsible for the area. f. Flight trials All the operational concepts developed within the GRICAS project have been demonstrated through a set of real-time in-flight trials: • A first campaign, called "ELT(DT) field trial" performed in Sabadell, Spain, onboard a Cessna 182 in April 2017. It was meant to be an in-flight dry-run of the future flight trials and was dedicated to the adjustment of the test equipment. All the test sce- narios were performed in-flight and the first in-flight independent local- ization using the MEOSAR system was realized, with results even better than expected. • A second campaign, called "in-flight RLS field trial" performed in Sab- adell, Spain, onboard a Cessna 182 in November 2017. Its objective was to test the Return-link Service (RLS) user cases defined in the GRICAS operational concept with the pre- operational RLS Provider (RLSP). • A third campaign, called "Commer- cial aviation field trial" performed in Toulouse, France, onboard a Falcon 20 of SAFIRE (The French Service of Instrumented Aircra for Envi- ronmental Research) early Decem- ber 2017. Its objective was to test the GRICAS SGB ELT(DT) onboard an aircra offering a flight domain simi- lar to the one of an aircra dedicated to commercial flights (as targeted in GADSS). e Falcon 20, with its 800 km/h cruise speed and 10 kilometer cruise altitude was a perfect test air- cra for this flight trial. • A four t h f light tria l, ca l led t he "Final Commercial Aviation field trial", performed in February 2018 in Dakar, Senegal, onboard the ATR 42 test aircra of ASECNA. It was a field trial mostly dedicated to dis- semination activities around the Cospas-Sarsat compliance to ADT requirements and the improvement of SAR in Africa. In addition, a helicopter field trial was performed in July 2017 in Graulhet, France, onboard an AS 350 B2 Eurocop- ter "Squirrel" helicopter. It aimed at ini- tiating work on addressing the problem of ELT(DT) designed for rotorcra. For these campaigns, a dedicated platform was developed by PildoLabs in the frame of the project, following the standards and best practices used for laboratory equipment devices that are carried out in research aircras (see Figure 5 ). is demonstration platform contains as main equipment the Sec- ond Generation ELT(DT) developed by ELTA, a Remote Control Panel to moni- tor the beacon status and an EGNOS GNSS receiver to be used as the bea- con's position external reference. The platform was temporarily installed in the aircra during the flight campaigns and connected to the SAR antenna, as it can be seen in Figures 6-8 . e manufac- turer also developed an emulator of the Beacon Activation Logic that sends the automatic activation command to the beacon when triggering criteria are met. e flight tests performed during the project are unique in many aspects: • It was the first time that an ELT(DT) prototype, representative of what a real ELT(DT) could be, flew onboard airplanes and a helicopter, and was automatically triggered in-flight. • It was the first time an independent localization of a second generation Cospas-Sarsat beacon was comput- ed during a transmission on-board a flying aircra and helicopter. • It was the first time that the Gali- leo SAR RLS was used to remotely activate an ELT(DT) aboard a flying aircra. • Finally, it was also the first time first and second generation beacons

Articles in this issue

Links on this page

view archives of Inside GNSS Media & Research - MAY-JUN 2018