Specifications

Background
10
CCD FPGA
JPEG2000 Hardware
Compression (ADV212)
ARM7
Microprocessor
Storage
(FLASH memories)
TX
ADCS
LCD Filter
Figure 8: Electronics Layout Block Diagram
The result is a 50 Mbit image reduced down to 3 Mbit. JPEG2000 also provides
quality features like region of interest coding (ROI) and different types of progressive
transmission. The AMSC will guarantee a ground resolution of about 40 m from an
altitude of 720 km.
2.2 STARS
In the framework of the project internally funded by the University of Bologna,
named STARS - Standalone Three-Axis spacecraft oRientation Sensor, a team composed
by two separate departments, DIEM and DEIS, investigated the feasibility of a novel
standalone spacecraft attitude sensor, capable of estimating the full three-axis orientation
of an Earth-orbiting satellite. The underlying idea is that by capturing from space a
sequence of images of the Earth surface (in the visible bands) and elaborating them in
pairs through feature extraction, feature matching, homography estimation and finally
attitude estimation.
The following project steps have been carried out: selection of enabling technologies,
definition of the attitude determination algorithm, numerical simulations followed by an
acquisition campaign on a experimental test-bed.
In the early phase the selection of suitable enabling technologies was performed in
order to allow the use of imaging Earth sensors as standalone attitude sensing hardware
on board an Earth orbiting spacecraft, then the attitude determination algorithm was
selected. To do this a dedicated simulation environment was developed and its structure is
shown on Figure 9. Inside the Microsatellite Laboratory a Matlab/Simulink model was
generated to simulate a spacecraft orbit, giving the instantaneous position (altitude,
latitude and longitude) and orientation (in form of quaternions).