Satellite Search and Rescue (SAR) standards are set and overseen by COSPASSARSAT. SAR instruments are currently flying on board MEO satellites in several GNSS constellations. These platforms complement the existing LEOSAR and GEOSAR satellites. Existing LEO/GEOSAR are slow in detecting an active beacon due to several limitations in design (limited satellites, fast orbits, no independent location capability, etc.). MEOSAR exceeds the individual advantages of each of the other options but they are not perfect either, e.g. accuracy is still in the order of km and localisation of moving fast-moving beacons is not possible. 

After the incident in March 2014 when the Malaysian Airlines MH370 flight disappeared from radar screens leaving very little information about its location, the International Civil Aviation Organization (ICAO) requested COSPAS-SARSAT to work on SAR capabilities, particularly on the context of flight tracking during a distress event.

Combining High Altitude Pseudo Satellite (HAPS) with multi-layer  LEO/MEO/GEOSAR ranging would improve beacon localisation. HAPS can also be quickly moved over a specific location within the designated service area. Another HAPS benefit is the improved link budget, between 30 and 40 dB, depending on its altitude. Furthermore, TOA/FOA measurements with considerably increased SNR are expected to  improve the independent localisation of distress beacons. 

Additionally, HAPS platforms deployed in the sky could complement locally existing surveillance systems by: 

• extending coverage and add redundancy:
• enabling ad-hoc communications between Rescue Team and person in distress:
• enabling real-time video feed over the area of interest, which is expected to be useful for planning and coordination of rescue operation.

The overall objective of the activity is to conduct a feasibility study on the use of HAPS platforms as a mean of local augmentation to SAR services. 

The tasks to be performed will include:

• review of LEO/MEO/GEOSAR in terms of vulnerabilities, current and future needs, and stakeholders;
• critical analysis of HAPS layer in SAR, with identification of benefits and limitations;
• defining a technical concept making use of HAPS for SAR and evaluating its implementation feasibility;
• developing simulation models for the technical concept to perform trade-offs;  validating the technical concept based on simulations.

The main results of the activity will provide:

a clear picture on the fitness of HAPS platforms as a potential future complementary local augmenting global SAR services (for which EU has a regular coordinated approach with Cospas-Sarsat);

a simulation tool capable to support trade-offs and technical analysis of HAPS for SAR.