Working Group Meeting November 22, 2005

1. Working Group MeetingNovember 22, 2005

2. Agenda • 2:00 Welcome & Introductions. Review agenda. • 2:10 LGS AO System Status & Schedules • Purpose: Informational • 2:15 Collisions • Purpose: Reduction of frequency & impact of collisions • 3:00 Aircraft safety & Laser Clearinghouse • Purpose: Reduction of overhead (summit aircraft safety system, improved LC interaction) • 3:25 Mauna Kea Laser Policy • Purpose: Update policy if appropriate • 3:40 Other issues? • 3:50 Next steps & action items • Purpose: Clear path forward PW

3. Welcome & Introductions • MK LGS TWG: • Doug Simons (Gemini) • Hideki Takami (Subaru) • Christian Veillet (CFHT) • Richard Wainscoat (UH) • Peter Wizinowich (Keck) • Other Participants: • Gemini: Mathieu Bec, Celine d’Orgeville, Francois Rigaut • Keck: Randy Campbell, David Le Mignant, Doug Summers • Subaru: Yutaka Hayano PW

4. LGS AO System Status & Schedules • Keck • Gemini • Subaru PW

5. Keck LGS AO:The top priority for Keck Science • Keck II: Laser propagation summary and plans • Operational model by 07A:1 OA at HQ to operate LGS & 1 at summit to monitor laser & safety systems in addition to telescope • Keck I • 20W mode locked CW laser contracted with CTI • LGS AO system design in FY06. Implementation into FY08. DLM

6. Gemini LGS AO • GN: 12W laser and Altair • LGS first light on May 2, 05 • 2.5 nights for LGSF technical commissioning (May 05) including star wars test w/ Keck + 16 nights for Altair LGS technical commissioning (June, July, Aug, Sep, Nov 05) • Science commissioning on hold until Feb 06 LLT M1 re-polished; 10-12 nights planned in 2006A • Commissioning of instruments in LGS mode: NIFS, etc. • Operational model for 06B:1 laser tech at summit to prep laser in the afternoon and monitor laser & safety systems for first part of the night, remote support from home/HP as needed • GS: 50W laser and MCAO • 50W mode locked CW laser contracted with CTI, delivery in Jan 07 • MCAO I&T through 2006 • LGS first light in 2007A, tech + science commissioning by end of 2007B Cd’O

7. Subaru LGSAO • 188 element curvature sensor AO 4W sum frequency laser collaborated with RIKEN at Nasmyth focus (10W upgrade is planned) • 2005/10 Laser projection demo in Japan • 2006/1 NGS laboratory closed loop Laser & LLT deliver to Hilo • 2006/8 NGS first light • 2006/12 First projection of laser to the sky • 2007/3 LGS first light HT

8. LAYOUT of Subaru LGSAO Instruments IRCS, HiCIAO HT

9. Collisions • Collision frequency & impact • Keck statistics • Is this consistent with predictions? • Rayleigh scatter impact • Subaru measurement of Keck beam • UH image • Impact of cirrus • Impact on instruments • CFHT, Gemini, Keck, Subaru, UH • URLs • How are they set at each Observatory? • Can this be done better • LTCS • Gemini/Keck test • What should be improved • Ideas for reducing collision frequency & impact PW

10. Collision Frequency & Impact • Keck statistics • Average of 18 min time lost to collisions per night • Time altered considerably more: broken dither pattern, switching to lower priority object, taking more calibrations than necessary, etc. • Notes: • Collide with all telescopes (except UKIRT?) • Don’t collide with K1 more frequently (likely because no impact flag set whenever possible) • Some recent collisions apparently during slewing by other telescopes (UH & Subaru) • Had collisions while aligning laser at zenith when CFHT & Subaru weren’t tracking (collecting twilight flats) RC

11. Collision Frequency & Impact • Gemini preliminary data • Data not automatically collected yet • Based on May, June, July, Aug, Sep and Nov 2005 engineering runs (lots of zenith propagation, no “real science” and no queue yet): 0-3 collisions/night (none in 2-night Nov run!?) RC

12. Scatter Impact Measurement withKeck II and Subaru (Hayano et al. 2003) • Keck II was pointed to SAO99809 on December 24, 2001. (El ~ 70 - 80). • Subaru was pointed to fixed direction. (El = 45, 60). • Scattered light was measured by APDs of Subaru AO WFS. • Three collisions were observed. YH

13. Scatter Impact Measurement withKeck II and Subaru (Hayano et al. 2003) • Pupil plane measurement for finite FOV q (e.g. 1 arcsec). • If (d+L q) < D, pupil does not illuminate fully. (Larger D, closer laser beam L). • Smaller telescope affected more. • Sky background proportional to D2, while laser beam scattered light proportional to min(D2, D(d+L q)). • Imager with smaller pixel scale less sensitive to laser beam scattering. • Laser beam seems to be bright to naked eye or a sky monitor camera. • Focal plane measurement. • Laser beam scattered light completely defocused with a size of (d+D)/L radian. • 1 arcmin @ 30km, 0.5 degree @ 1km • 19 arcsec @ 90km, (LGS size at focal plane) • If LGS magnitude is 10, • 14mag/arcsec2 @ 80m (19x38 arcsec2) • 18.8mag/arcsec2 @1000m (19x231 arcsec2) YH

14. Estimation of Scatter Impact (Hayano et al. 2003) • Rayleigh scatter and Mie scatter model • Number density of molecule is derived from Hilo radio-sonde observation. (for Rayleigh) • Aerosol distribution mode is estimated from AERONET database and particle counter data at Subaru for Mie scatter evaluation. (Scale height of aerosol was ~ 3km. It was class ~14000 at Mauna Kea.) • Model calculation showed that the number of Rayleigh scattered photons was about 6 times as much as that of Mie scattered photons. • Roughly speaking, the surface brightness of 17.5 mag/arcsec2 is comparable to the sky brightness at about 15 degrees away from full moon. • The impact is larger for smaller and nearer telescopes. YH

15. Rayleigh Scatter Impact from digital photograph • Factor 8 brighter than dark sky in R (2.2 magnitudes) • Factor 4 brighter than dark sky in V (1.5 magnitudes) Dark sky: R: 20.3 mag/(“)2 V: 21.1 mag/(“)2 RW

16. Rayleigh Scatter & Cirrus • Current Keck propagation criteria have been revised in KAON 318 1. The laser must be shuttered if spotters detect an aircraft within 25º of the beam. • The laser must be shuttered if thick clouds are present within 25º of the beam, preventing approaching aircraft from being seen. • Our experience is that we have been able to propagate through thin cirrus (& have productive LGSAO science nights). The spotters report to the Observing Assistant (OA) on the passing of thin clouds that could produce an increase in scattered light. The OA & LGSAO operator monitor the scattered light using the WFS intensity display, the acquisition camera and other available tools; if the amount of scattered light is such that the laser return has decreased by more than a factor 2 on the WFS (0.75 mag), the LGSAO operator & OA will close the shutter. DLM

17. Impact on Instruments - Keck Keck I, Keck II, Both PW

18. Impact on Instruments - Gemini a) All wavefront sensors use patrol fields centered on telescope’s field except GMOS b) When used in conjunction with ALTAIR c) Centered 2.5 arcmin off-axis d) LGS wavefront sensor DS

19. Impact on Instruments - CFHT • "Prime" or "MP" fov = 1.1667 • "Cass" fov = 0.8 • "I.R." fov = 1.1667 • "Coude" fov = 0.8 • anything else fov = 1.1667 • This is actually old information at a time when the TCS could not recognize the instruments. It needs updating with the current instrumentation and better numbers for the FOV. • "Prime" should be the only one at 1.1667! • "I.R" (the new WIRCam) is much smaller, and there should not be "anything else"! CV

20. Impact on Instruments - Subaru * They are the upper limit of the search area, HT

21. Impact on Instruments - UH 2.2-m • Tek 2048: FOV 0.18 deg 0.4-1.0 microns • Optic CCD: FOV 0.22 deg 0.4-1.0 microns • 8k CCD: FOV 0.78 deg 0.4-1.0 microns • Offset Guider: FOV 0.83 deg 0.4-1.0 microns • ULBCAM: FOV 0.4 deg 1.0-1.8 microns (no impact) • WFGS2: FOV 0.26 deg 0.4-1.0 microns • SNIFS: FOV 0.002 deg 0.3-1.0 microns RW

22. Impact on Instruments - IRTF • Guider (on axis): FOV 0.008 deg 0.4-1.0 microns RW

23. Standard URL • Includes the following fields (as per the LTCS_URL_Interface_Specification dated Feb 7, 2002): • Timestamp1 - local time (time of URL update) • Telescope - telescope name • RA - telescope right ascension (hrs) • DEC - telescope declination (deg) • Equinox - equinox and epoch of coordinates • FOV - diameter of field of view • Laser_impacted - telescope is (or is not) laser sensitive • Laser_state - telescope is (or is not) projecting a laser • log_data - flag to enable/disable logging of pointing data • Timestamp2 - local time (time of URL update) DS

24. URL setup – KECK1 & KECK2 • URL updates accomplished automatically via programmatic control (Java/solaris): • FOV values determined via current instrument lookup • RA/DEC/Equinox set from TCS with az/el/frame conversion to RA/DEC/Eq (as needed) • LASER_IMPACT set from combination of domeshutter state, dome track state, and telescope track state. • LASER_STATE set from laser fast-shutter state (with capability to override) • Program runs in near-real time; as fast as keyword layer parameter changes occur, notification & rewrite of the URL file occurs. DS

25. URL setup – Subaru • URL address • http://www.naoj.hawaii.edu:8011/cgi-bin/ltcs.cgi • http://www2.naoj.hawaii.edu:8011/cgi-bin/ltcs.cgi (backup) • http://www3.naoj.hawaii.edu:8011/cgi-bin/ltcs.cgi (backup) • Update interval of URL page is changed by executing some commands through “at” table from 15 seconds to 1 second during LGS observation. • FOV is set to be 1 degree for Prime Focus Camera and 8 arcmin (FOV of AG roughly) for other instruments. (tentative) • RA/DEC/EQUINOX information is gottenfrom TCS. • TIMESTAMP is gotten from NTP server at Subaru. • Information collected from the telescope telemetry server almost in real time. • LASER_IMPACT sets if RA/Dec changes slower than 0.1 deg/sec. (tentative patch on Nov. 10, 2005)

26. URL setup – Subaru • Prof. Ryu Ogasawara still manages the URL setup, even after he moved to ALMA project. (Handover is to be scheduled.) • Are we clear on who the URL contacts are at each Observatory? • Prof. Ryu Ogasawara (ryu.ogasawara@nao.ac.jp) • Handover is to be scheduled soon. • Yutaka Hayano (hayano@subaru.naoj.org) • How is laser propagation information supplied to nighttime operations personnel? • The announcement of laser projection is circulated the mailing list of operation center including night operators and support astronomers.

27. URL setup • CFHT • Gemini (128.171.88.53) • UH • IRTF • Are we clear on who the URL contacts are at each Observatory? • How is laser propagation information supplied to nighttime operations personnel? DS

28. LTCS • Current LTCS version (1st Generation): • Limited testing with other telescopes • Limited resources for development & testing (LTCS & URLs) • Installations & version consistency between Keck, Gemini, Subaru • URL Site issues: • Some manual (vs. TCS/programmatic control) setting of parameters • RA/DEC precision & slew issues being worked with Subaru • Slewing with Laser_impacted=YES (most observatories) • Re-development of LTCS by Subaru. • 2nd generation LTCS SW install & testing: • Consistency with La Palma SW baseline (Joint dev, more functionality) • New priority-based rules (backward compatible to MK config) • Laser/Laser “first on target” wins algorithm included • New tools (simulation/Query) • Slew filtering (auto-detection) & notification • Some improvements over 1st generation issues above, but also some similar issues (more coordination for version control & bug fixes, etc.) DS

29. LTCS Positional Errors & URL polling • Positional Error: • Current version uses FOV cone extension (currently 10% for all telescopes in MK config) as error term. • 2nd generation LTCS adds survey inaccuracy parameter to base telescope position (effectively an aperture increase) • URL polling rates: • Kecks: 1 sec • Gemini: 1 sec • UH2.2: 1 sec • CFHT: 3 sec • Subaru: 3 sec • IRTF: 5 sec • STALE processing for all sites is currently configured for 120 seconds. DS

30. Other LTCS Issues • LTCS priority rules: As laser investments increase to 4 lasers on MK, should we consider migration to a La Palma type collision priority rules model (first-on-target wins)? • All telecopes have access to Query/planning tools for target selections. • Favorable query response indicates ability to stay locked on target throughout observation; unfavorable response indicates collision times (for planning when to shutter science camera and/or laser depending on who has priority). • Maximizes fairness & observing efficiency; reduces shutter time • Ability to configure fully independent priority rules; can have ELT (for instance) have priority over all telescopes or establish custom priority rules for each telescope/laser combination. DS

31. Ideas for Reducing Collision Frequency & Impact • Better collision predictions • No impact while slewing • More careful setting of URL • Instrument fov • Laser impacted flag • Observer program taken into account? • Distinction between Na & Rayleigh scatter impact • Different criteria for shuttering DS

32. Aircraft & Satellite Safety • FAA renewal & issues • Spotters • Boresight camera systems (Gemini, Keck) • Gemini wide field camera system • Mosaic radar? • Collaboration with other groups (JPL, Palomar)? • Laser Clearinghouse • How do we want to collaborate? PW

33. FAA Renewal & Issues • Keck proposal renewed till Dec. 06 • Keck’s experience • Requested collection and compilation of spotters data (aircraft and weather) is a cumbersome process, yet interesting for statistics on laser propagation & operations. • 2 aircraft incidences since 2001 (and we shuttered per procedure) • 2006 renewal process: 1 month FTE, benefited from previous renewals • Would like to review proposal process w/ other observatories. • Our FAA contact: “doesn’t have a lot of faith in oxygen-deprived observers looking in a star-filled sky for aircraft”. Yet, understands the expense to the observatory, and the logistics involved. • FAA actually recommends working on implementing the JPL system that is currently being reviewed. DLM

34. FAA Renewal & Issues • Gemini’s experience • Current permission (our first; not a renewal) valid until April Fools’ Day 2006. • With our first application, the FAA (Larry Tonish) sent us a fairly routine set of questions, which we answered, after consulting with Jason Chin (thank you, Jason). • They wanted to ensure that our spotters were going to be provided with protection from the weather and hypoxia. • After answering the questions they granted us permission for a period of one year. • We are in the midst of a process to obtain permission to operate lasers at Gemini South. The Chilean FAA equivalent has been very cooperative. • Following Keck’s model to collect statistical information on spotter data. KB/BG

35. Spotters • Logistics for managing aircraft spotting is resource intensive • Managing spotters pool (hiring, training, schedule) • Transportation & safety • Procedures and spotters logs • Meals and equipment • Time sheets and payment • Keck’s experience: • Two lead spotters responsible for transportation, training and coordination. • Spotting procedures reviewed and re-enforced in Nov.2005 • Whole process is problematic because we are dealing w/ part-time outside resources. • Keck use of aircraft spotters • http://www2.keck.hawaii.edu/optics/lgsao/docs/kaon360.pdf DLM

36. Spotters • Keck has built a base of spotters from an outside resource • Gemini uses the same pool of spotters • This pool of spotters must originate from the Keck because of specific background checks that is mandatory in Keck’s HR policy. Gemini does not have the same requirements. To keep recruitment of the spotters consistent, Keck HR has agreed to manage the initial recruitment of the spotters from the outside resource. • Gemini’s experience: • Before assigning a spotter to a Gemini run: • They are given a safety orientation from our safety officer. • They are given a general orientation for our laser program from AO program manager(s). • Gemini prefers to schedule the spotters for each run internally. The Engineering Admin Asst calls available spotters from the pool (from outside resource) for assignments. • Two lead spotters were recently hired to the Gemini staff and are assigned to every run with a team of 3 additional spotters from the outside resource. The leads are responsible for transportation and direction of the spotter team. • The scheduling is not a big issue and is not time consuming. Most of the time, spotters call to request scheduling. Using the outside resource is an not an ideal situation. Our experience with the outside resource has not been a completely positive one. KB

37. Boresight Camera Systems • Gemini • ~15 fov Merlin - Indigo IR camera • Continuous imaging & real time analysis • Aircraft detection signal sent to LIS/GIS to activate safety shutter • Keck • 10 fov Amber IR camera • Aircraft detection automatically closes fast shutter through PLC within 1/30th of a second • Can trigger on moon & can be overridden PW

38. Gemini Wide Field Camera System • Status • Software demonstrated • Camera mounted on SMA roof • Camera damaged by sunlight • Enclosure dome inadequate - too much scattered moonlight • No work on this for several months • Plans? • Fix the current problems • Daytime shutter, new or modified camera enclosure, … • Continue with integration and testing • Continue collaborations Cd’O

39. Mosaic Radar • History • 07/91 – Boeing & FAA agreement for Haleakala completed • 11/99 – AFRL/Boeing development effort begins • 05/01 – SW & HW integration complete; Boeing authorized from FAA to provide UH with data • 08/02 - Maui AF contingent tours MK, fails to break through political issues related to technical transfer of info; correspondence essentially stops. • Outstanding Political Issues: • AF/Boeing/FAA MOA/MOUs needed before docs & technical info can be provided/discussed in detail. • Access to FAA data may be sensitive to international institutions • FAA Certification for MK system (regardless of technical approach) • Existing System Technical Issues: • Blind spots, multi-target correlation, simple azimuth wedge avoidance cone, manual laser position input, shutter control integration, HW & SW constraints, MK data access method. DS

40. Collaboration with other Groups? • JPL • Keith Wilson (JPL Optical Communications Group) attempting to establish a consortium of interested parties to work with FAA on navigable air space safety solutions • Next step: Telecon strategy session • Table Mountain system for day & nighttime propagation • 2 boresighted LWIR cameras for low flying aircraft • Radar beam to detect high flying aircraft • Exploring FAA radar interface display system. Next step: fund prototype development • Palomar Cd’O

41. Laser Clearinghouse • Keck’s Experience • Observer submit target list using web interface 3 days in advance • Still faxing target list and receiving approval fax • Never got any closures on target list • Lost ~4 hours in 2005 due to sudden call for “space events” • Received same-day approval for special requests: GRBs and human error on main targets. • Issues • Still lots of coordination with observers and US SC: effort level is ~5 hours per observing proposal for reliable operations. • Could it be more automated (approval email could work) DLM

42. Laser Clearinghouse • Gemini’s Experience • We fax the target list and receive approvals by fax or email. During our November run, we requested approvals to be emailed to a group of people. We received an email both days of our run indicating no closures. • Never received any closures on target lists. • Received same-day approval for special requests: Adding new targets or changing targets. • Issues • Coordination with observers and US SC runs pretty smoothly. • A more automated way of submitting for approvals would be ideal. Submit by email or by web interface. KB

43. Aircraft & Satellite Safety: Collaboration • How do we want to collaborate? PW

44. Mauna Kea Laser Policy • Policy • Keck Policies • Lasers at different wavelengths • Any reason to review policy? • Weather PW

45. Mauna Kea Laser Policy The following policy statement was approved at the Sept/97, Mauna Kea Directors’ meeting. “The use of sodium D wavelength (589 nm) laser guide stars for astronomy is permitted on Mauna Kea subject to the following conditions: • No Observatory shall project a sodium laser beacon exceeding a power of 50 W. Multiple beacons can be projected from a single Observatory as long as their total power does not exceed 200 W. Laser beacons may not be projected at a zenith angle greater than 70 degrees. • Laser beacons must not interfere with observations being performed by other Mauna Kea telescopes. Any Observatory pointing a laser beacon must, therefore, adhere to the observing coordination guidelines approved by the Mauna Kea Directors. • Any Observatory projecting a laser beacon must receive prior approval for their aircraft system from the FAA. Only passive aircraft detection systems are permissible. Written confirmation that conditions 1 to 3 have been met by an Observatory must be provided to the IfA Director at least 30 days prior to the first projection of a laser beacon from that Observatory. Use of guide stars at alternate wavelengths will be permitted only after an evaluation of their utility and impact, similar to that performed for sodium D wavelength lasers, is carried out and is submitted to and approved by the Mauna Kea Directors.” • It was noted that for some Observatories that the use of laser beacons may require a modification to the indemnification clause in the “Operating and Site Development Agreement” between the Observatory and UH. It was also noted that a requirement may need to be added in the future to the policy statement on the subject of satellite avoidance. PW

46. Keck Laser Propagation Policies • Laser propagation restrictions & procedures • http://www2.keck.hawaii.edu/optics/lgsao/docs/kaon269.pdf • Procedure for laser safety observing • http://www2.keck.hawaii.edu/optics/lgsao/docs/kaon361.pdf • LGS AO weather cancellation policy • http://www2.keck.hawaii.edu/optics/lgsao/docs/kaon318.pdf

47. Lasers at Different WavelengthsCFHT VASAO (Visible All Sky AO Concept) • Feasibility study ongoing, to be completed by end of 2006. • Could be operational around 2011-2012. • Based on: • Pueo Hou: Pueo upgrade to allow diffraction limited observations in visible above ~600nm & 50mas resolution below. • Two mode-less lasers at 589nm & 569nm (giving 330nm through radiative cascade) • Polychromatic tip-tilt sensor • Use of a 330nm laser for tip-tilt sensing (that would give both wavelengths at once) is also contemplated, though feasibility is not proven yet. CV

48. Mauna Kea Laser Policy: Changes?

49. Other Issues PW

50. Next Steps PW