Image compression systems on board satellites

The European Space Agency (ESA) recently proposed the space wire standard for reliable satellite on-board networking at high speeds. This paper presents the design of configurable space wire router and interface hardware macrocells, the first in state-of-the-art compliant with the latest standard extensions, protocol identification and remote memory access protocol. The space wire router with 8 links achieves 100 Mbits/s data rate with 135 W power consumption and 300 Krad radiation tolerance. These performances meet the requirements of planned ESA space missions

Radiation Tolerant SpaceWire Router for Satellite On-Board Networking

Mobile communications has seen an explosive growth in the past five years with the integration of communications devices and multimedia applications. Transport connections set up over wireless links are frequently plagued by such problems as a high bit error rate (BER), frequent disconnections of the mobile users, and low wireless bandwidth that may change dynamically. Proposed developments in B3G and 4G wireless services will further challenge researchers to come up with efficient devices that can handle the huge data transmission. Fast and low-power compression algorithms are greatly needed to accommodate the specification. This paper highlights and analyzes various next-generation image-compression algorithms developed on the basis of image transmission via a wireless channel. In addition, the performance comparisons between the proposed hardware implementations are shown. Two important findings are discovered: First, the high-speed reconfigurable devices called FPSoC are the best hardware implementation. Second, a vector-quantization-based VSPIHT algorithm offers the best solution of parallel processing in efficient hardware architecture. This article serves as a reference point for researchers developing image-compression algorithms for next-generation mobile-communications devices.

Hardware implementations of an image compressor for mobile communications

This paper presents low-cost, purpose optimized discrete wavelet transform-based image compressors for future spacecrafts and microsatellites. The hardware solution proposed here exploits a modified set partitioning in hierarchical trees algorithm and ensures that appropriate reconstructed image qualities can be achieved also for compression ratios over 100:1. Several implementations are presented varying the parallelism level and the tile size. Obtained results demonstrate that, using a parallel implementation operating on a 64 /spl times/ 64 size tile, a maximum data rate of about 18 Mpixels/s can be sustained. In this case, only 4500 slices and 24 BlockRAMs of a XILINX Virtex II device are required.

Low bit rate image compression core for onboard space applications

This paper presents a low-power 128-tap dual-channel direct-sequence spread-spectrum (DSSS) digital matched-filter chip. Design techniques used to reduce the power consumption of the system include latch-based register file filter structure, a high-rate compression scheme, optimized compressor cells, and semicustom layout design. To further reduce the power consumption and the hardware requirement of the clock tree, a double-edge-triggered clocking scheme is adopted. The proposed chip is fabricated using a 0.8-/spl mu/m standard CMOS process. As the experimental results of the chip indicate, the matched filter can operate at 50 MHz and dissipates 184 mW at 5-V supply voltage. The supply voltage can be scaled down to 2 V for lower speed applications. As a consequence, the proposed design has low power consumption and can be used for code acquisition of DSSS signals in portable systems.

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A low-power digital matched filter for direct-sequence spread-spectrum signal acquisition

In this study, a real-time image processing subsystem, GEZGIN, which is currently being developed for BILSAT-1, a 100kg class micro-satellite, is presented. BILSAT-1 is being constructed in accordance with a technology transfer agreement between TUBITAK-BILTEN (Turkey) and SSTL (UK) and planned to be placed into a 650 km sunsynchronous orbit in Summer 2003. GEZGIN is one of the two Turkish R&D payloads to be hosted on BILSAT-1. One of the missions of BILSAT-1 is constructing a Digital Elevation Model of Turkey using both multi-spectral and panchromatic imagers. Due to limited down-link bandwidth and on-board storage capacity, employment of a realtime image compression scheme is highly advantageous for the mission. GEZGIN has evolved as an implementation to achieve image compression tasks that would lead to an efficient utilization of both the down-link and on-board storage. The image processing on GEZGIN includes capturing of 4-band multi-spectral images of size 2048x2048 8bit pixels, compressing them simultaneously with the new industry standard JPEG2000 algorithm and forwarding the compressed multi-spectral image to Solid State Data Recorders (SSDR) of BILSAT-1 for storage and down-link transmission. The mission definition together with orbital parameters impose a 6.5 seconds constraint on real-time image compression. GEZGIN meets this constraint by exploiting the parallelism among image processing units and assigning compute intensive tasks to dedicated hardware. The proposed hardware also allows for full reconfigurability of all processing units.

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A Real Time Image Processing Subsystem: GEZGIN

GEZGIN-2 is a real-time image processing subsystem, currently being developed for RASAT, the second small satellite to be launched by TUBITAK-BILTEN, in 2007. It is an advanced version of the GEZGIN payload, implementing JPEG 2000 image compression algorithm and currently flying on the BILSAT-1 satellite. The main enhancements in GEZGIN-2 are the integration of the full processing path of JPEG 2000 algorithm in a single Field Programmable Gate Array (FPGA) for increased processing performance and high speed data links complying with the ESA Spacewire standard, for data transfer at a rate of 100 Mbps. In addition to JPEG2000, GEZGIN-2 facilitates image pre-processing for cloud/sea detection and image/data encryption implemented on a daughter-board called GOLGE. As in GEZGIN, GEZGIN-2 allows for adjustment of compression ratio for different mission times by means of run-time supplied parameters and full reconfigurability in orbit.

GEZGIN-2: an advanced image processing subsystem for Earth-observing small satellites

A digital FM receiver/demodulator system, utilizing the zero-cross detection technique, is designed and implemented on a single IC. Zero-cross detection is performed at an IF frequency of 455 kHz. The system is simulated for BT=0.3 GMSK input with an input data rate of 8000 bps and displayed a better BER performance than coherent detectors. The developed system is implemented in 0.5 /spl mu/m triple-metal standard digital CMOS technology. Power dissipation of the resultant IC is less than its analog counterparts while the occupied silicon area is very small making it low cost. The FM receiver/demodulator IC is suitable to be used in low-power and low-cost mobile communication applications providing better BER performance than conventional systems, especially in noisy channels.

Low-power design of a digital FM demodulator based on zero-cross detection at IF

GEZGIN is a real-time image processing subsystem, developed as an R&D payload for BILSAT-1, the first Earth observing micro-satellite of Turkey The main functionality of GEZGIN is to compress in real-time multi-spectral images coming concurrently from the 4-band multi-spectral imager on BILSAT-1, using JPEG2000 image compression algorithm The mission definition of BILSAT-1 imposes a 55 seconds interval constraint between two consecutive multi-spectral images with 20% overlap GEZGIN fulfills this mission requirement by exploiting the parallelism among image processing units and assigning compute intensive tasks to dedicated hardware The architecture of GEZGIN is highly integrated and fully reconfigurable allowing for the upgrade of all processing units in orbit Hence it maintains flexibility and robustness against failures which are crucial properties for space applications GEZGIN is built at low cost using completely "commercial-off-the-shelf" components and having performed well in all the flight readiness tests, has been successfully integrated on BILSAT-1 It is currently undergoing orbital tests

GEZGIN: a case study of a real-time image processing subsystem for micro-satellites

In this paper, we present an architecture and a hardware implementation of the 2D Discrete Wavelet Transformation (DWT) for applications where row-based raw image data is streamed in at high bandwidths and local buffering of the entire image is not feasible. The architecture is especially suited for multi-spectral imager systems, such as on board an imaging satellite, however can be used in any application where time to next image constraints require real-time processing of multiple images. The latency that is introduced as the images stream through the DWT filter and the amount of locally stored image data is a function of the image and tile size. For an n/sub 1/ /spl times/ n/sub 2/ size image processed using (n/sub 1//k/sub 1/) /spl times/ (n/sub 2//k/sub 2/) sized tiles the latency is equal to the time elapsed to accumulate a (1/k/sub 1/) portion of one image. In addition, a (2/k/sub 1/) portion of each image is buffered locally. The proposed hardware has been implemented on an FPGA and is part of a JPEG2000 compression system designed as a payload for a Low Earth Orbit (LEO) micro-satellite, which will be launched in August 2003.

N. Ismailoglu

Papers

A Real Time Image Processing Subsystem: GEZGIN

GEZGIN-2: an advanced image processing subsystem for Earth-observing small satellites

Low-power design of a digital FM demodulator based on zero-cross detection at IF

GEZGIN: a case study of a real-time image processing subsystem for micro-satellites

A real-time, low latency, FPGA implementation of the 2-D discrete wavelet transformation for streaming image applications