Airbus Defence and Space

PLATFORM DATA HANDLING

Mosaic GNSS Receiver LEO, MEO, GEO

GPS Receiver as Stand-alone Box for LEO, MEO and GEO

GNSS

GPS Receiver as Stand-alone Box for LEO, MEO and GEO

The MosaicGNSS receiver is a dedicated high quality radiation-tolerant GPS single board receiver for applications in LEO, MEO and GEO. It is a L1 C/A Code receiver, which is capable of acquiring and independantly tracking up to eight GPS satellites.

A key feature of this receiver is the implementation of signal processing in software. The receiver is designed to process weak signals and its dynamic navigation solution provides PVT (Position, Velocity, Time), even in situations where less than four satellites are visible. Synchronisation to GPS time is provided by one Hertz Time Mark Pulse.

The unit can be used as part of a modular spacecraft AOCS or stand alone, in a single or fully redundant configuration.

The MosiacGNSS receiver consists of the central processing electronics together with optional GPS patch antenna, filter, and LNA.

Key Features

  • Unique feature: signal processing implemented in software
    • Fast PVT solution (time-to-first-fix)
    • Processing of weak signals for GEO applications
  • Capability to work with only two GPS satellites signals with the same precision
  • Configurable and patchable in orbit²
  • Operational in LEO, MEO and GEO with the same HW/SW configuration
  • Class 1 and class 2 versions available

Main Application Fields

  • LEO, MEO and GEO satellite

Customers / Application

  • First launch in 2006, currently (jan. 2012) 8 receivers operational in orbit with 18 years of accumulated time in orbit (e.g. TerraSAR-X)
  • As of jan. 2012, more than 40 single receivers have been ordered for different missions worldwide

Budgets

Mass

3.9 kg

Volume

272 x 284 x 92 mm3

Power

10 W

Interfaces

Data Interface:

X SpaceWire, RS-422 UART,

 

MIL-Bus 1553

Antenna Interface:

50 Ω, SMA connector, 9 V for LNA

Input Voltage:

24 - 35 V, 35 - 52 V

Performances

GPS Receiver performances (3D RMS):

  • L1 (1575.42 MHz), C/A Code receiver
  • 8 channels, for spaceborne applications

Accuracy

 

Position

Velocity

Time

LEO

< 10 m

< 0.01 m/s

< 100 ns

MEO

< 30 m

< 0.02 m/s

< 200 ns

GEO

< 150 m

< 0.02 m/s

< 750 ns

Dynamic Conditions

Doppler shift

± 60 kHz

Doppler rate

± 60 Hz/s

Max slew rate

0.5 ˚/s

Sensitivity Threshold

Tracking

26 dBHz

Acquisition

30 dBHz

Data Output:

PVT and raw measurements at 1 Hz, point and / or

 

dynamic solution, ECEF or ECI, GPS Time

Pulse Output:

RS-422

1Hz, synchronised to GPS Tim

Environments

Temperature

-20 ˚C to +60 ˚C (operating)

 

-40 ˚C to +80 ˚C (Non-operating)

Radiation Tolerance:

up to 100 kRad

Life time

up to 15 years

The complete redundant MosaicGNSS receiver assembly is composed of:

  • Two GPS receiver modules
  • Two DC/DC converter modules
  • Two LNAs
  • Two GPS L1 patch antennas
  • Associated RF cables between above components
  • The RF front-end performs analogue downconversion of the received RF signal (l1 frequency and subsequent A/D conversion.
  • The boot PROM holds the primary boot loader which performs first hardware initialization and loads the main application either from the EE PROM bank or from a communication interface. The EEPROM bank contains the main application.
  • The GPS pre-processing includes digital downconversion, filtering, decimation and packaging functions.
  • The boot and boot controller maintains various interrupt signals, general purpose I/O lines and a power-on reset for the DSP.
  • The communication interface inside the GPS ASIC provides three high speed serial communication channels: one SpaceWire interface and two UART interfaces. An optional MIL-STD-1553 bus inter face is also available.
  • The DSP used is a TSC21020F processor, the space qualified equivalent of the ADSP-21020. Program memory and data memory are separated (Harvard architecture).
  • Furthermore, a separate power converter board has been added for the DC/DC conversion.

Optional add-on services

  • Mission analysis, specific compatibility tests
  • EGSE for closed loop testing
  • AOCS integration and hardware accommodation support
  • Pre-& post-launch maintenance
  • Operator training

 

Download fact sheet

Download fact sheet

First launch in 2006, currently (jan. 2012) 8 receivers

operational in orbit with 18 years of accumulated

time in orbit (e.g. TerraSAR-X)