1. THEMIS/GBO Engineering Peer Review 1 UCB, Oct. 17, 2003 Ground Based Observatories (GBO) Engineering Peer Review Oct. 17, 2003 Data Retrieval and Software Configuration Brian Jackel University of Calgary

2. THEMIS/GBO Engineering Peer Review 2 UCB, Oct. 17, 2003 Imager data processing transmission and storage Site computer timing monitoring security Outline

3. THEMIS/GBO Engineering Peer Review 3 UCB, Oct. 17, 2003 Imager on-site data flow physical transport network transport On-site storage Network gateway

4. THEMIS/GBO Engineering Peer Review 4 UCB, Oct. 17, 2003 Imager data center Public Receiver (warm spare) Receiver Test Storage http, scp, rsync.... Data products network transport physical transport

5. THEMIS/GBO Engineering Peer Review 5 UCB, Oct. 17, 2003 Imager on-site data flow imagerd always running acquisition from camera when sun-angle > 108° prepend site information site_info.conf store as ASCII PGM /tmp/recent_image.pgm create thumbnail convert image to PNG, copy to /data/imager/ tree /tmp/recent_image.pgm P2 #"Site code" CALGU #"Site name" Calgary University #"Site location" 51.1139N 114.02W 1084m #"Site notes" University of Calgary Physics #"Imager code" THEMIS01 #"Exposure start time" 2003-09-27 04:38:45 UTC #"Exposure finish time" 2003-09-27 04:38:47 UTC #"Exposure duration" 1000 ms #"Exposure type" VIS #"Image size" 376 290 #"CCD binning" 2 1 #"CCD offset" 0 0 #"CCD DAC" 16 #"CCD device" /dev/ccdA 376 290 65535 3124 2900 2929 3018 3087 2992 2942 3166 2954 3001 2906 2910 2998 3066 2909 3041 3017 3015 2972 3214 3082 2955 3028 2974 2966 2957 3041 2939 3107....

6. THEMIS/GBO Engineering Peer Review 6 UCB, Oct. 17, 2003 If an ASI frame looked like this: Then the a coarsely binned map of aurora will look like this: Image to thumbnail lo n lat y x

7. THEMIS/GBO Engineering Peer Review 7 UCB, Oct. 17, 2003 If the lat/lon auroral map looked like this: Then the ASI frame would look like this: Thumbnail to image Make a “thumbnail bins” image file where each pixel value provides a reverse mapping to the corresponding thumbnail bin. Use as quick lookup table. Needs to be calculated each time a camera is installed or moved.

8. THEMIS/GBO Engineering Peer Review 8 UCB, Oct. 17, 2003 Image thumbnails thumbnaild always running wait for change in timestamp of /tmp/recent_image.pgm run pgmtothumb which uses thumbnail_bins.pgm to average 16-bit pixel values in each bin, convert to 8-bits, output as binary PGM to /tmp/recent_thumbnail.pgm copy to /data/imager/ tree compress with gzip and transmit over network with udp_sendfile /tmp/recent_thumbnail.pgm P5 # ATHA THEMIS00 VIS # NBINS 20 20 # MLAT 55-65,0.5 # MLON 129-149,1.0 # binning created 2003-10-03 14:15:15 20 20 255...sequence of 8-bit binary values... /usr/local/etc/thumbnail_bins.pgm P5 # ATHA THEMIS00 VIS # NBINS 20 20 # MLAT 56-61,0.5 # MLON 129-135,1.0 # binning created 2003-10-03 14:15:15 376 290 65535...sequence of 16-bit binary values...

9. THEMIS/GBO Engineering Peer Review 9 UCB, Oct. 17, 2003 Orientation from Stars instrument_nameThemis00 site_nameAthabasca site_codeATHA geodetic_latitude54.72 geodetic_longitude246.72 geodetic_altitude250.0 camera_yaw58.0 camera_tilt0.5 camera_pitch0 optics_a11.53 optics_a20.0 optics_a30.0 optics_b10.0 optics_b20.0 ccd_nx290 ccd_ny290 ccd_x0146.0 ccd_y0155.0 ccd_xflip1 ccd_yflip-1

10. THEMIS/GBO Engineering Peer Review 10 UCB, Oct. 17, 2003 Data directories and filenames Data directory tree: /data /mag/... /status/ / / /imager/ / / / _ /ut eg. /imager/2003/10/17/ATHA_THEMIS00/ut02 Image filename convention: _ _ _ _ _.png eg. 20031017_024205_ATHA_THEMIS00_VIS_1000ms.png At 5-second cadence there will be 720 images/hour

11. THEMIS/GBO Engineering Peer Review 11 UCB, Oct. 17, 2003 Site-specific configuration Minimize software configuration differences between site computers physical location network configuration image thumbnail map local log files ?? /usr/local/etc/site_info.conf #"Site code" ATHA #"Site name" Athabasca Geophysical Observatory #"Site location" 54.72N 246.72E 676m #"Site notes" Athabasca University in northern Alberta

12. THEMIS/GBO Engineering Peer Review 12 UCB, Oct. 17, 2003 Computer site timing computer clocks typically not reliable network time synchronization (NTP) over satellite may require excessive bandwidth, not reliable GPS provides 1 pulse-per-second with 50ns accuracy, UTC time string for NTP reference tests of Trimble Palisade unit indicate offsets on the order of 20ms using RS-232 ASCII signal software conflicts can prevent NTP synchronization /usr/sbin/ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== LOCAL(0) LOCAL(0) 10 l 29 64 377 0.000 0.000 0.015 -wham.phys.ucalg CLOCK.UREGINA.C 2 u 55 64 377 0.343 20.253 0.057 xdancal.phys.uca CLOCK.UREGINA.C 2 u 8 64 377 0.569 76.535 1.921 +fsa.cpsc.ucalga subitaneous.cps 2 u 64 64 377 2.301 20.129 0.050 +time.nrc.ca tac.nrc.ca 2 u 28 64 377 96.307 18.981 0.265 *GPS_PALISADE(1).GPS. 0 l 27 32 377 0.000 -0.482 0.071

13. THEMIS/GBO Engineering Peer Review 13 UCB, Oct. 17, 2003 Site computer monitoring CPU and motherboard temperatures, fan speeds hard drive temperature, error rates clock status (NTP) network status power status (UPS) free disk space, memory web-cam? ??

14. THEMIS/GBO Engineering Peer Review 14 UCB, Oct. 17, 2003 Data synchronization Every day, each site computer will calculate checksums for previous day of thumbnails copy data to external disk (if present) if less than 5% free disk space, lossy compress or delete oldest data Every day, a central computer will download checksums from remote sites identify intervals of missing or compromised thumbnails, pull from sites

15. THEMIS/GBO Engineering Peer Review 15 UCB, Oct. 17, 2003 Site computer security Any system on the internet will eventually be attacked. Plan for this now, or waste time reacting later. linux software fully patched before deployment accounts: imager (UCalgary, UCB), mag (UCLA, UAlberta), root for emergency/maintenance only firewall: access only from specific subnets (ie. phys.ucalgary.ca, ssl.berkeley.edu, phys.ualberta.ca,...) firewall: access only from specific ports (ie. ssh, rsync, ntp,...) login attempts logged locally and remotely, key configuration files checked periodically

16. THEMIS/GBO Engineering Peer Review 16 UCB, Oct. 17, 2003 Site software changes don't (unless absolutely necessary) document reasons for and specific details of change run on test machine for as long as possible push to one active site after making snapshot of complete current state push to other active sites, again after snapshotting burn CDs with new basic state, keep with copies of previous states