Airbus Defence and Space


COME, compression and mass memory unit

The COME has been developed in the frame of Airbus Defence and Space’s new generation of Low Earth Orbit observation satellite. Derived from the already flight proven SPOT compressor, it features high performances and cost effectiveness. The main functions of this unit are the compression based on wavelet and image storage of CCD signals. The design is based on compression/storage slices allowing adaptable definitions and attractive redundancy limiting hardware.

Features / technical details

The COME receives input signals from CCD signal data conversion through HDMP 1032/1034 links. The focal plane outputs are connected to different compression/memory slices. Each slice can compress 5*20Mpix/s on 12 bits. The associated memory is up to 2*96Gbits.

COME is based on 3 types of boards :

• Compression and memory management board : CCM board

• Memory board : 96 Gbits in two planes

• DCDC converter board. Each board can supply 3 slices.

Key Performances

• Wavelet Image COmpression Modules (WICOM) , Fixed rate

• 3 High Speed Redunded Input Serial Links : Agilent1034, 1 High Speed Redundant Output Serial Link : Agilent1032

• line-CCD Non-Uniformity Correction, Compression, source packet format

• configurable : from 1 channel @100+ Mpix/s 12 bits for monospectral to 20 channels @ 5+ Mpix/s 12 bits for superspectral

• Control of Redunded Mass Memory Bus

• RS & CCSDS frame formating

• MIL STD 1553 TM/TC interface

• 2 independent 48 Gbits banks ; Integrity via Reed Solomon EDAC

Budgets for Pleiade application :

• 5 slices among 6 : 9 CCM, 6 MEM, 2 CV

• Power :≤ 60 W during Data Retention , ≤ 78 W Memory active, ≤ 216 W during imaging and compression

• Mass ≤ 34 kg

• Dimensions: 335*395*302 mm³ (L x W x H).


High resolution imaging systems

Reference customers

CNES for PLEIADE High Resolution Instrument.