Implementation of a robust transmission system for astronomical images over error-prone links Paul Thienphrapa, Helen Boussalis, Charles Liu, Khosrow Rad, and Jane Dong Department of Electrical and Computer Engineering California State University, Los Angeles 5151 State University Drive Los Angeles, CA 90032, USA ABSTRACT The James Webb Space Telescope (JWST) is expected to produce a vast amount of images that are valuable for astronomical research and education. To support research activities related to the mission, the National Aeronautical and Space Administration (NASA) has provided funds to establish the Structures Pointing and Control Engineering (SPACE) Laboratory at the California State University, Los Angeles (CSULA). One of the research activities in SPACE lab is to design and implement an effective and efficient transmission system to disseminate JWST images across networks. In on our previous research, a prioritized transmission method was proposed to provide the best quality of the transferred image based on the joint-optimization of content-based retransmission and error concealment. In this paper, the design and implementation of a robust transmission system is presented to utilize our previously proposed methods over error- prone links. The implemented system includes three parts. First, a zero-tree based error-resilient wavelet codec is used to compress the incoming astronomical image at the sender. Tree-based interleaving is adopted in packetization to increase the system’s capability to combat burst losses in error-prone channels. Second, various error concealment approaches are investigated and implemented at the receiver to improve the quality of the reconstructed image. The transmission system uses UDP as the transport protocol, but with an error control module to incorporate the optimal retransmission with the delay constraint. A user-friendly graphical interface is designed to allow easy usage for users of diverse backgrounds. 1. INTRODUCTION One of the major goals of the NASA ORIGINS program is to determine the origins of life in our universe. To this end, the JWST, which is scheduled for deployment in 2011 as the successor to the Hubble Space Telescope, has been designed to achieve greater optical range and sensitivity than the Hubble. En route to discovering the origins of life, vast amounts of high-quality astronomical image data must be analyzed, so the JWST is expected to produce large quantities of such images for ground-based observation. Astronomers, as well as scientists in related fields, from around the world must be able to simultaneously access these images quickly in order to conduct research productively. Additionally these images must be made available for education and public outreach purposes as well. As such the design of a system for the efficient and effective transmission of astronomical images across a global network is a topic of importance. The SPACE Laboratory was established at CSULA in 1994 under funding from NASA to study some of the new technologies that need to be developed as part of the James Webb Space Telescope project 1 . In particular, one of the SPACE Laboratory research activities involves the design of an efficient image transmission system that is optimized for astronomical images. Due to the great optical range, sensitivity, and volume of images that the JWST will generate, as well as the marked interest by the scientific community to study these images, such a system is essential in enabling productive ORIGINS-related investigations throughout the world. By balancing the constraints of network bandwidth, time delay, and image quality, and by capitalizing on the properties of astronomical images, a novel image transmission system would allow audiences, including scholars, educators, and the general public, to maximize their respective efforts in the study of the images. This paper discusses the implementation of an astronomical image transmission system that considers the optimization of transmission using two different transmission technologies, namely content-based retransmission 2, 3 and error Multimedia Systems and Applications IX, edited by Susanto Rahardja, JongWon Kim, Qi Tian, Chang Wen Chen, Proc. of SPIE Vol. 6391, 63910G, (2006) · 0277-786X/06/$15 · doi: 10.1117/12.690109 Proc. of SPIE Vol. 6391 63910G-1 Downloaded from SPIE Digital Library on 21 Jan 2010 to 128.220.159.9. Terms of Use: http://spiedl.org/terms