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AAS Camera

The AAS (Aircraft Avoidance System) is a compact complete camera, including an objective and a smart CMOS camera, that is used to assist a single or multiple Laser Guide Stars (LGS) Adaptive Optics (AO) system to detect the presence of aircrafts in a specific sky area in order to rise an alarm to turn off the laser beam in order to avoid any risk.


AAS main features

  • The AAS is based on a ‘smart’ CMOS camera with on-board computing processor, based on Linux OS, and special customized software

  • The AAS includes:

    • compact SKR IR CINEGON  objective with Focal length: 4.8 mm, F-number: 1.8,

    • sensor unit (SU)

    • processing unit (PU)

    • communication unit (CU)

  • The SU is equipped with E2V EV76C660 CMOS sensor that features: 1.3 million (1280 x 1024) pixels, 5.3 μm square pixels with micro-lens and 10 bit / pixel ADC

  • The SU is in a small sensor unit box that consists on a sealed enclosures with a valve to provide gas filling. Gas (Argon or Krypton) filling is required for the SU box if the cooling system is enabled to minimize internal humidity avoiding frost when reaching lowest sensor temperatures.

  • The cooling system is based on a 5.5x6.5 mm Peltier cell controlled by the PU.

  • The PU is based on AM335x 1GHz ARM® Cortex-A8 Processor that manages the CMOS, image processing, the alarm generation, the cooling, the communication services. 

  • The CU provides both main system and the service communications between the camera and the telescope control unit:

    • the main communication is provided by conversion of the 10/100TX ETH of the PU to 10FL/100SX 850nm fibre optic pair lines

    • the service comminication  consists on a RS232 UART line

  • The AAS is a self-contained module, requiring only power supply and a single fiber/LAN Ethernet connection

  • Easy control of operations using ascii strings through TCP/IP Ethernet channel

  • Discrete Inputs (Power-On, Start Alarm, Shutdown); discrete Outputs (Aircraft Detected, Increased Background, System On, Watch Dog)

  • Power 24V @ 0.6A max with over/under voltage and over current protections

  • A cylindrical aluminum (h: 322 mm x d: 220 mm) housing with a 27.5 ° sloped pedestal protects the camera from wind shake and dust 

  • Complete support service: customization, commissioning and maintenance during operation

Please contact us for documentation and quotations


AAS example application: ESO Paranal UT4 telescope 4 LGS unit

AAS 2Gen has been developed by Astrel Instruments for the 4LGSF of the ESO Adaptive Optics Facility, to be installed in pair on the UT4 telescope at ESO Paranal Observatory. The AAS commissioning has been completed in January 2020. The two AAS cameras are planned to be installed on UT4  telescope top ring on Q4-2020.



AAS at Paranal.jpg

The AAS 2Gen on ESO VLT platform (Paranal- Chile) 


An example image from AAS

Images Copyright by ESO