1. Image acquisition in the  of the sky project supervised by: Krzysztof Poźniak, Ph. D. Krzysztof Poźniak, Ph. D. Institute of Electronic Systems Grzegorz Wrochna, Ph. D. Grzegorz Wrochna, Ph. D. Institute for Nuclear Studies Warsaw Polytechnics Institute of Electronic Systems PERG Group Michal Jegier Part of M.D. Thesis

2. Plan of presentation Summary of work done for MD thesis: 1.Introduction 2.Basic studies over algorithms used in astronomy imaging 3.Driver for communication in Linux 4.Driver-wrapper class „Device” in C++ 5.Graphical interface in Java

3. Introduction Processing must be performed online due to large stream of data (8MB/cycle/camera), all actions have to be taken without delay Processing must be performed online due to large stream of data (8MB/cycle/camera), all actions have to be taken without delay Recognition of optical flashes Recognition of optical flashes Interaction with triggers from GCN network (receiving and sending triggers) Interaction with triggers from GCN network (receiving and sending triggers) Controling hardware via Internet Controling hardware via Internet The system of cameras is a remote system, situated at Las Campanas, Chile. No human interaction is possible, so complete automation of retrieving and processing images is necessary The system of cameras is a remote system, situated at Las Campanas, Chile. No human interaction is possible, so complete automation of retrieving and processing images is necessary

4. Basic studies over algorithms used in astronomy imaging Task: Comparison of two images of the sky taken by stationary camera Problem: Direct comparison is not possible due to apparent movement of the sky Solution: Finding rotation and offset between the two images and applying found transform to one of them Series of transformed images put together

5. Algorithm 1. Finding coordinates of stars, matching gaussian curve into star profile 2. Matching lists of stars from the two adjacent frames Number of operations required (brute-force): (n1*n2)^2 Number of operations is greatly reduced (to a few) thanks to: - Using qsort() and bsearch() functions - Optimized to find small offset and rotation - The brightest stars play the most important role

6. 3. Finding transform between the found stars using the least squares method x' = a x - b y + c y' = a y +b x + d R = sqrt(a^2 + b^2); cos[alfa] = a/R; sin[alfa] = b/R

7. Task: Compression of acquired images Problem: Compression of large data streams, losless Solution: Compression using Rice codes Only changing part of 16-bit number representing pixel is put to the output data stream (differential coding). BA CD If ((A==B) & (A==C)) Predictor_D = (A+B+C)/3 The difference is acquired using extended set of linear predictor from a few neighboring pixels, example: Ratio of compression is 2 – 3 depending on the noise Implementation for Linux and Windows

8. USB Driver for Linux Direct Memory Access using sg-lists, not working Direct Memory Access using user_map_pages, not working -> additional load on processor Specific sequence of loading and unloading drivers Use of Vendor commands for Cypress EZ-FX2 protocol Camera’s watchdog refresh, using kernel timers Overriding timeouts  The system is remotely controlled; special approach is needed in order to provide reliability  Low level driver for kernel 2.6 – tested & debugged features:

9. Driver-wrapper class „Device” in C++ CommandDescriptionComments 0xFD „Artificial” RESET EZ-FX2 does not provide normal reset 0xFC Watchdog refresh Refreshes watchdog in camera so that it does not reset 0xDD Download firmware to Altera Provides possibility of updates 0x0D LNA gain control 0xEF Get version of cam Cameras cannot be confused anymore 0xE lens heating Vendor – over control pipe 0 Download firmware to Cypress Provides possibility of updates Enables to perform complicated sequences of commands Watches timing requirements for commands Over 20 simple and complex functions implemented

10. Graphical interface in Java The following simple interface will be further developed...

11. ... and will have the following properties: Client-server based approach Bridge between existing code in C++ and java Compatible with Linux and Windows Automatic device detection Graphical representation of images Standard functions of graphical interface

12. Plans Development of graphical interface Development of graphical interface Final preparation of thesis, including other prepared software Final preparation of thesis, including other prepared software Final exam: September, 2006