ELU Subsystem Performance Requirements
The ELU shall decode received messages from the command and control center and rescue forces.
The ELU shall display transmission acknowledgement and estimated rescue time.
The ELU shall provide a fixed position and time tag of the downed crew member.
The ELU shall transmit at a frequency of 140MHz.
The ELU shall complete transmission of location data in less than 0.23 seconds.
The ELU shall provide automatic status of crew member condition based on EKG results.
The ELU shall provide location accuracy of less than 5m from the downed aircraft.
The ELU shall have an active receiver at all times once communication is established with the satellite network.
The ELU shall compute its position to within 100m using signals from multiple satellites.
The ELU shall send updated alert messages that are activated by the ELU operator to the rescue vehicle.
The ELU shall append a coded incapacitation message automatically after 5 minutes of detecting no operator entries.
The ELU shall be self powered 24 hours a day for a continuous period of up to 10 days.
ELU Functional Requirements
Operable with crew member incapacitated
the crew member’s ELU must be contained within the crew member’s ejection package
Positive identification of downed aircraft and crew member
Relay global position to SAR TOC
Interoperability allowing other forces to receive SAR information to assist as necessary in the SAR operation (search, no-fire zone, protection)
All weather, day/night operation
Mission planning to assure timing and location for rescue under safest practical conditions.
ELU Performance Requirements
- Accept EKG sensor input from standard flight suit data connector
- Interpret EKG sensor data to assess crew member status as
- Signal Failure
- Automatically initiate position update messages every 30 minutes if crew member status is other than Conscious
- Withstand ejection and subsequent ground strike environmental and dynamics profiles associated with all aircraft currently in service
- Weight of ELU shall be less than 15lbs
- Accept coded signal from microprocessor
- Exchange synchronization, access and PIN codes with the LEO satellite constellation
- Accept daily crypto key data from SAR Command Center
- Exchange signals with aircraft data entry system sufficient to positively identify crew member and aircraft to SAR personnel
- Receive notification of impending rescue from rescue vehicle via LEO downlink
- Process GPS Satellite signal to identify location within 100m
- Receive un-coded signals from command and control center
- Send a position update upon manual request
- Send a series of 30 position updates upon manual request at a rate of 1 per minute
- ELU shall operate in the following conditions:
- Temperature -32 to 60 degrees C
- Rain 0.5 in/hour
i. Sustained 40kt
ii. Gusts 70kt
- ELU shall have the following SWaP characteristics:
|Item||Weight (lb.)||Size (cu. in.)||Power|
|Battery (lithium organic)||1.0||16.0||104-w hrs|
|Power controller & bus DC/DC converters||1.0||20.0||80% eff.|
|Oscillator (1x10*-8)||0.8||20.0||0.2 w|
|GPS Receiver||2.0||24.0||3.0 W|
|LEO sat. Transceiver||2.5||22.0||16 w peak (0.25 sec)|
|Microprocessor Controller||1.0||16.0||1 w|
- Accept "clean" power from the power supply unit
- Communicate with the LEO satellite system according to the following parameters:
|Transceiver power||4 w|
|Transmit frequency||140 MHz|
|Modulation||frequency shift keying|
|Bit rate||2000 bps|
|Bits transmitted per message||216|
|Transmission length||0.25 sec|
|1 x 10*-8|