Eis and Solar-b science Meeting November 15-17 eis science Team Meeting November 18 and 19 eis, xrt and fpp solar-b science Meeting



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EIS and Solar-B Science Meeting
November 15-17 EIS Science Team Meeting

November 18 and 19 EIS, XRT and FPP Solar-B Science Meeting

1999

Naval Research Laboratory

Action Items
How big will the frame buffer be - resolved later with a request for at least 15 Mbytes. The needs more complete study.
CCD format/size?
IDL routines for calculating throughput are available now and the calculations will also be made available via a web script.
The need for a public-orientated (promotional/outreach) web site that would be an 'Introduction to Solar-B' was noted. The more technical EIS team site should be separate, but accessible, from that site.

**ACTION on the science team: to define the requirements for observing modes and HOW MUCH data memory is required.


**ACTION on MSSL: to investigate the possibility of designing a more flexible OB system and the cost implications.
**ACTION on the SOLARB and EIS teams: to clarify and define science operations
**ACTION on John Mariska: to make available the IDL routine which produces count rates from standard CHIANTI QS, AR and Flare spectra.
**ACTION on NRL and RAL: for this to be made available also as a web-based facility. Wang and Mariska will look at putting together a web-based photon sensitivity-calculating tool for EIS investigators to play with. Dave Pike agreed to begin putting together an IDL tool for simulating throughput. John Mariska will provide his IDL photon sensitivity program as a beginning.
**ACTION on Dave Pike: to produce an IDL version of MK_EIS, based initially on CDS's mk_raster. This should eventually evolve into something more flexible.
**ACTION on LOUISE HARRA: to produce a new science requirements document.
**ACTION on Rob Gowan: to provide a schedule with deadlines for decisions which depend on science requirements.
**ACTION on EIS team and Rob Gowan: to explore the scientific requirement to accommodate 2 CCD data blocks simultaneously.
ACTION: Ed DeLuca to define IDL procedures for developing observing sequence incorporating operations of XRT, FPP and EIS.



Task

Person

Finish Date

Investigate science case for 1” and 2” slits

Helen

End of Jan 2000

Investigate science case for 50” and 100” slits

Ken

End of Jan 2000

Investigate science case for multi-slit slot

Joe

End of Jan 2000

Investigate science case for the short slot

Ken

End of Jan 2000

Investigate how many sequences can be run, when they start and for how long

Rob (with input from Dave)

End of Jan 2000

Investigate the maximum number of windows necessary for good line coverage

Dave

End of Jan 2000

Re-write the description of ‘rastering’ in a more variable way

Dave

ASAP

Tidy EIS web site and start a easy access general separate web page

Louise

End of Jan 2000

Investigate the accuracy of coronal coalignment with SXT and CDS

Dave & Louise

Early April 2000



Agenda
Monday morning, November 15
9:30 Welcome by George Doschek

Chair: Tetsuya Watanabe

Secretary: Steve Myers
Science investigation topics
9:40 Active regions: Louise Harra

10:10 Flares: George Doschek

11:10 CMEs: George Simnett

11:40 Quiet Sun: Helen Mason



Monday afternoon, November 15
Chair: George Doschek

Secretary: Dave Pike


EIS hardware (heavily emphasizing those aspects which affect science)
1:45 optical design: Clarence Korendyke/Charlie Brown

2:15 cameras and electronics: Rob Gowan/TBD

2:45 photon sensitivity: John Mariska

3:45 calibration: Jim Lang

4:15 EIS instrument specifications

and other useful web documentation: Louise Harra



Tuesday morning, November 16
Chair: George Simnett

Secretary: John Mariska


Data throughput and compression
9:00 EIS data throughput: Rob Gowan

9:45 compression studies: Dave Pike, Dennis Wang

11:00 observing programs and data throughput: Ken Dere

Tuesday afternoon, November 16
Chair: Joe Davila

Secretary: Helen Mason


CDS lessons learned: Dave Pike

Comments from SUMER operations: George Doschek and John Mariska

Observing programs: Louise Harra

coordinated observing, co-alignment, operations, observing modes, flare flag




Wednesday morning, November 17
Chair: Jim Lang

Secretary: Ken Dere


Data archiving and database: Tetsuya Watanabe and Len Culhane

Data analysis and software: Dominic Zarro, Bill Thompson, Stein Vidar Haugan



Wednesday afternoon, November 17
Chair: Len Culhane

Secretary: George Doschek


EIS Science Requirements: Louise Harra

EIS/XRT/FPP Solar-B meeting, November 18-19


Thursday morning, November 18
9:30 Welcome by George Doschek
Chair: John Davis

Secretary: Harry Warren

Description of instruments and observing capabilities

9:40 FPP: Tom Berger/Jake Wolfson

10:10 XRT: Ed Deluca

11:10 EIS: Len Culhane


End-to-end data throughput, J-side view: Tetsuya Watanabe

Thursday afternoon, November 18
Chair: John Mariska

Secretary: Louise Harra


Coordinated observing programs:

1:40 XRT: Ed Deluca

2:10 FPP: Tom Berger

3:10 EIS: Ken Dere


Co-alignment: Bill Thompson, Ken Dere
Influence of TRACE observations on Solar-B science: Harry Warren

Friday morning, November 19
Chair: Jake Wolfson

Secretary: Andrzej Fludra


Planning and operations

Yohkoh: Watanabe

SOHO: Dere
Data archiving, databases and management

SOHO: Zarro

Data analysis and software

Coordinate systems and FITS files: Bill Thompson

Solar Soft Tree: Bill Thompson/Dominic Zarro

_________________________________________________________

Note: Each session has a Chair whose role is to ensure that the session stays on schedule, that the contributions of each attendee are presented and integrated into the program and to try to bring to a focus and resolve issues that come out of the discussions. There should be considerable time in the schedule to accommodate a considerable amount of time for general discussion.
The role of the secretary is to provide a written record of the sessions beyond what is incorporated in the copies of the viewgraphs that are presented. In particular, the secretaries will make notes of issues that are resolved and those that cannot be resolved. Each speaker should provide the session secretary with copies of their viewgraphs to be organize and given to Ken Dere.

Each person named after a discussion topic is to serve as a discussion leader for that topic. They are expected to make a presentation on that topic and lead the discussion on that topic but are not expected to provide a definitive discussion of any particular topic. The Chair will co-ordinate the presentations by other interested attendees.


Everyone is encouraged to present material on any and all topics. Please inform the chair of the session that you would to address so that we can get everyone into the schedule and provide the secretary with a copy of any viewgraphs. There should be sufficient time to have a fairly free general discussion of all topics.
The material provided to us by the secretaries will be used to construct a proceedings that will be distributed shortly after the meeting.


Monday morning, November 15
9:30 Welcome by George Doschek

Chair: Tetsuya Watanabe

Secretary: Steve Myers
Science investigation topics
9:40 Active regions: Louise Harra

10:10 Flares: George Doschek

11:10 CMEs: George Simnett

11:40 Quiet Sun: Helen Mason




Speaker: Louise Harra


Topic: Active Regions

Materials Presented: 3 viewgraphs

Louise lead a twenty-five minute lecture on the heating mechanisms leading into what we have to explain. In support of this discussion, Joe Davila presented graphic materials from his paper currently in review. Copies of the viewgraphs and hard copy Davila graphs are provided. At the close of the lecture, a general discussion among attendees was conducted; no critical areas of concern were identified during this lecture.

Speaker: George Doschek


Topic: Flares

Materials Presented: 22 viewgraphs

George lead the lecture on the unsolved problems of solar flare physics and solar flare dynamics revealed by Yohkoh and previous missions. Data from Skylab and Yohkoh were presented. Discussions on the topic areas were supported with the use of viewgraphs; copies of these viewgraphs are provided. At the close of the lecture, a general discussion among attendees was conducted; no critical areas of concern were identified during this lecture.
Speaker: George Simnett

Topic: CMEs

Materials Presented: 22 viewgraphs; LASCO/SOHO Insights Summary

George lead the lecture insights into CMEs using data obtained from LASCO. Discussions on the topic area were supported through viewgraph materials and a distributed summation paper on the relevance of LASCO/SOHO; copies of these viewgraphs and paper are provided. During the lecture, Ken Dere presented supplemental material from EIT; copies of these viewgraphs are also provided. At the close of the lecture, a general discussion among attendees was conducted; no critical areas of concern were identified during this lecture.



Speaker: Helen Mason


Topic: Quiet Sun

Materials Presented: 9 viewgraphs

Helen lead a twenty-five minute lecture on dynamic/transient events discussing explosive events, blinkers and network flares in addition to the quiet sun structure citing and presenting materials previously published. Discussions on the topic areas were supported with the use of viewgraphs of published materials; copies of these viewgraphs are provided. At the close of the lecture, a general discussion among attendees was conducted; no critical areas of concern were identified during this lecture.

Monday afternoon, November 15
Chair: George Doschek

Secretary: Dave Pike


EIS hardware (heavily emphasizing those aspects which affect science)
1:45 optical design: Clarence Korendyke/Charlie Brown

2:15 cameras and electronics: Rob Gowan/TBD

2:45 photon sensitivity: John Mariska

3:45 calibration: Jim Lang

4:15 EIS instrument specifications

and other useful web documentation: Louise Harra




Optical Design: Clarence Korendyke
Talk included some areas which were to have been covered by Rob Gowan - this lead to a number of queries which were unresolved at this time, but which may have been clarified later in the meeting.
TBDs raised
1) content of slit assembly - various suggestions arose later in the meeting
2) Are science and HK data fed to MDP on the same channel (see Watanabe's talk?)
3) What is the EIS onboard processor (see Gowan's talk)?
4) How big will the frame buffer be - resolved later with a request for at least 15 Mbytes.
5) Are both (if two) CCDs read out simultaneously?
6) CCD format/size?
7) If alignment with other instruments needs to be <1" do we have to recalibrate every time the coarse mirror motion is used (2" repeatability)?
8) Various issues about pointing -
how often does EIS expect to use coarse pointing?
will s/c follow solar rotation in discreet moves (later answered NO)
note that thermal effects affect inter-instrument alignment at 0.5-1.0" level
9) Charge spreading in the detector will result in pixels with an effective size of approximately 17 microns.
10) There are still concerns over the effects of water vapor outgassing from the structure.
11) What does the TRACE experience tell us about expected noise rates in the SAA and other regions?

EIS Instrument Throughput: John Mariska
Issues/questions raised:
The filter supports will be out of focus at the slit, but the extent of the modulation they cause is still TBD.
What is the effective area of EIS compared to CDS?
IDL routines for calculating throughput are available now and the calculations will also be made available via a web script.
EIS calibration: Jim Lang
Note limited coverage of EIS ranges with calibrated lines. In the 170-210A range only one calibration line will be within the 'useful' wavelength range. This makes it imperative that an accurate model of sensitivity as a function of wavelength is available in order to scale the monochromatic absolute calibration measures. This applies to all components including the CCD (and its flatfield).
NRL has facilities for doing this but their suitability and availability for measuring EIS components is TBD.
The detector used in the lab calibration must be cooled to the expected operating temperature of EIS.
For in-flight calibration, future flights of SERTS may cover the short wavelength range of EIS - currently it only observes the longer wavelength range.
It was suggested that a clear position, or very large slot, be available in the slit assembly for calibration to avoid the problems experienced with CDS calibration when it was difficult to guarantee all light was entering the spectrograph. Most likely solution seemed to be to remove one of the slits specifically for the lab calibration.

EIS Instrument Specification and other documentation: Louise Harra
The EIS web site is to be updated and simplified with much of the older material being 'archived' to lower levels. Summaries of the contents should be available together with quick guides to the other instruments. The EIS pages will remain open (i.e. not be password protected). A request for more html format versions of documents was made.
The need for a public-orientated (promotional/outreach) web site that would be an 'Introduction to Solar-B' was noted. The more technical EIS team site should be separate, but accessible, from that site.
The reports of this current meeting would be hardcopy only.
Integrated Test and Operations System (ITOS): Dennis Wang
The existence, availability and zero-cost of ITOS were pointed out. Further details are available from the URL given on the viewgraph.

Tuesday morning, November 16
Chair: George Simnett

Secretary: John Mariska


Data throughput and compression
9:00 EIS data throughput: Rob Gowan

9:45 compression studies: Dave Pike, Dennis Wang

11:00 observing programs and data throughput: Ken Dere


EIS Data Throughput: Rob Gowan
Compression schemes looked at include


  • Polygonal—useless

  • H-Compress—see Wang presentation

  • Rice—appears to be best for lossless compression

  • Bit compression

CCD information



  • 2 ms to read half a line

  • 16-20 windows currently envisioned, discussion suggests that more may be a good idea

  • Conceptually, the camera has one CCD with four readout ports

  • Time to read one CCD using both ports will be 1 s

  • Not yet clear what processing time for each exposure will be. Compression of a large area of the CCD could be a throughput issue.

Discussion seemed to indicate that slit movement will be slow—possibly 1 min max. This could be an issue for high time cadence observations that wish to alternate between a slit and a slot.


Compression: Dave Pike and Dennis Wang
Adaptive polygonalization considered for CDS and not used. It appears to be useless for EIS.
H-Compress looks good and should be able to achieve compression factors of 5. A compression factor of 5 should be used for planning purposes. Planning for windows on the CCD should take H-Compress into account. 32x32 pixel blocks appear to be a good choice. Thus a window width and height of 32 or some multiple of it would be ideal. Processing speed may be an issue. Estimates are that 1 Mbyte of data can be processed in 5 s for a processor like that selected for EIS.
Observing Programs and Data Throughput: Ken Dere
There may be a scientific requirement to bring down all of both CCDs for the same exposure. It was not clear whether doing this sequentially was sufficient. The issue is how much memory is required.
The current duty cycle of 30 min for slit changes may be a science issue. Some scientists wish to cycle between the slit and slot rapidly. This has impact on mechanism lifetime and on disturbance torque requirements.
Taking windows on the CCD was allowed in CDS, but not used due to charge transfer inefficiency issues. There was a desire to make sure that there is an ability to extract windows at a later point in the processing chain in addition to doing it on the CCD. Again, this is among other things a memory issue.
Dave Pike agreed to begin putting together an IDL tool for simulating throughput. John Mariska will provide his IDL photon sensitivity program as a beginning.
Wang and Mariska will look at putting together a web-based photon sensitivity-calculating tool for EIS investigators to play with.
Tuesday afternoon, November 16
Chair: Joe Davila

Secretary: Helen Mason


CDS lessons learned: Dave Pike

Comments from SUMER operations: George Doschek and John Mariska

Observing programs: Louise Harra

3:00 coordinated observing, co-alignment, operations, observing modes, flare flag


DAVE PIKE kicked off the session with 'CDS - LESSONS LEARNED'.


The questions posed were: 'Should we operate EIS in the same way as CDS because it was successful, reliable and safe?' or 'Should we do something new and exciting, which may actually be better?'
In designing the operations software, two parameters to be minimized are: total uplink and onboard storage; the parameters to be maximized are: flexibility of control, level of control, safety, and information content of downlink. There are basically 5 parameters needed for an observation, but why restrict these to the fixed structure of a raster? Why not have flexibility? Why not make all levels of commands accessible, with no 'forced' packaging? To ensure safety, there would need to be human, software/hardware checks with restricted access to the operations software. The information content of the downlink could be improved over CDS (which is only about 60%) by predicting data rates, and having sufficient onboard memory and intelligence.
An alternative mode of operation could be conceived for EIS which:

1) retains the ability to specify key parameters individually

2) has the capability to issue any control parameters from DCS or program store

3) Includes basic programming concepts (conditionals, loops)

4) has a concept-proving model (software or hardware).

These ideas/proposals formed the basis of a long and lively discussion.


CDS did have the capability of doing some 'fancy' operation modes, including an event flag and increasing the cadence by 'shuffling' down the CCD column, but these have not been implemented. It seems that all most folk want to do is to raster over and over again. The 'sit and stare' mode was not originally designed as such, but fortunately the raster mode allowed for 'zero' step.
Flexibility in the onboard software requires vision and in addition sufficient onboard memory (i.e. expense!). The case was strongly argued that this is not an 'add on', but an essential science requirement for EIS.
**ACTION on the science team: to define the requirements for observing modes and HOW MUCH data memory is required.
**ACTION on MSSL: to investigate the possibility of designing a more flexible OB system and the cost implications.

GEORGE DOSCHEK then enlightened us on 'THE SUMER EXPERIENCE'


The SUMER operations software started off more rigidly with the definition of POPs (Predefined Operations Programs) loaded onboard. These were unusable in practice and the operations software ended up much more flexible than CDS, with the ability of the planner to design new observing programs from basic parameters, to test them and upload them on-line. The French team developed some sophisticated software with a widget interface (which drove some folk crazy). The German approach allowed planners to type in a list of parameters or even to type operations software directly into SCL (SUMER Command Language). The SUMER structure allowed flexibility and 'looping' of command sequences. The safety aspects were catered for by the need to verify the observing program with a simulator - both technically and photometrically. However, this procedure was not rigorous and still allowed programs to run which exceeded the photometric safety limits. The planners were often pressured, and mistakes could (and were!) made - fortunately none was catastrophic. When creating a SUMER study, there were default options for descriptive parameters. Often folk couldn't be bothered to type in new descriptions, which isn't at all helpful in compiling a catalogue of the data.
There were several standard SUMER observing programs, such as reference spectra, which are exceedingly useful. CDS also regularly runs 'synoptic' studies; full spectral scans and rasters. The SUMER observing sequences were identified by the name of the originator. The name of the planner was also identified. This is a great advantage when searching the catalogue. CDS did not allow 'personal' identifiers (except for Oslo, O_**).
A discussion followed on how EIS and SOLARB would be operated. Watanabe-san said that SOLARB would be operated in a similar way to YOHKOH. The questions of guest investigators, data access and rights, unified SOLARB datasets, target observations, JOPs (Joint Observing Programs) etc were raised. The YOHKOH team has a Bulletin Board which works well for data use co-ordination. It was proposed that this approach be provided for SOLARB. It was also proposed that a draft plan of science objectives be formulated for the first year.
**ACTION on the SOLARB and EIS teams: to clarify and define science operations
LOUISE HARA lead a discussion on EIS OBSERVING PROGRAMS
Louise discussed the progress with EIS observing programs. She pointed out the information on the web. An EIS study sheet is available with sequence details. A need was identified for a MK-EIS program to design EIS observing programs. This could be adapted from CDS's mk_raster. There was concern that this might reinforce the 'raster' concept as the basic building block for science operations, which may inhibit flexibility. However, there is a greater need to actually get this process of creating observing programs started. Eventually it would be better to have a more general approach to the planning software (taking account of the SUMER experience), which reflected the philosophy and architecture of the onboard software.
There is an urgent requirement for an EIS simulator, which predicts count rates and allows scientists to design observing programs. This is needed to explore the capability of and requirements on the EIS instrument. It is important to be able to simulate the parameters for real EIS data, including signal/noise, ntvs, vel. shifts, Intensity and also to consider compression modes. We need to know how long an observing sequence would take and what the telemetry requirements are.
**ACTION on John Mariska: to make available the IDL routine which produces count rates from standard CHIANTI QS, AR and Flare spectra.
**ACTION on NRL: for this to be made available also as a web-based facility
**ACTION on Dave Pike: to produce an IDL version of MK_EIS, based initially on CDS's mk_raster. This should eventually evolve into something more flexible. The general discussion returned again to the requirements for onboard software. The practical implementation of the scientific requirements are for: a table based (more general than CDS) system; a command interpreter level; real image processing. An intelligent event flag is envisaged which could detect changes (e.g. brightenings) and respond by allowing EIS to change to a mode with higher cadence. This would require an operating system in which there was SMARTS intelligence upstairs (OB) as well as downstairs. Another proposal was that information (pointing co-ordinates) could be fed through to EIS from other instruments onboard SOLARB. There was a discussion about the LASCO onboard software, which has the capability of about twenty different analysis operations on the data.
An intelligent onboard operating system requires memory (how much?) which is a resource (limited by physical space and finance: hardware purchase and software development). The science requirements must be clearly defined - it was pointed out that 'total flexibility' is not an option! The OB hardware design for the Proto-Model (PM) has to be decided by 1st Jan. 2000 (buffer sizes for OB data storage and programming). The software design has a longer timescale. The current OB architecture was designed around draft science requirements. Radical changes are difficult at this stage, but some flexibility is available. The PM must be delivered by Feb. 2001, the FM a year later. It is possible for changes to be made between the PM and FM. The Preliminary Design Review is in March 2000. In summary, the hardware (CCDs) must be determined; the mass memory and working memory sizes must be decided; the architecture and operating software must be defined. There is a basic footprint limitation for the ICU Board for memory, but it is possible that technical developments may allow greater capacity in a years time. However, there are other limitations; power, space and cost. The memory requirements are set between 4 and 24 MBytes (with a strong pressure to meet the higher value). These sizes are based on CDS and RGS experience. They accommodate the data block from one CCD.

**ACTION on LOUISE HARRA: to produce a new science requirements document.


**ACTION on Rob Gowan: to provide a schedule with deadlines for decisions which depend on science requirements.
**ACTION on EIS team and Rob Gowan: to explore the scientific requirement to accommodate 2 CCD data blocks simultaneously.

The discussion moved on to telemetry, with questions such as 'Can EIS overwrite its portion of the Data Recorder (to provide temporary/alternative storage)?


The issue of co-alignment was discussed. Watanabe-san confirmed the spacecraft pointing stability as 0.3" per 1s, 0.9" per 10s and 5" per orbit (100 min) (at a 3 sigma level). Concern was expressed about the implications with regard to spatial 'blurring' for long exposures and uncertainty in the slit positions during long duration rasters.
Different slit options were discussed. Should there be a 100" slot or a 2" slit? A completely different type of multi-slit was proposed by Joe Davila - a grid of 10 slits, each 1" covering 50" in spatial extent. This was considered to be a very interesting idea.

SUMMARY
There is a scientific requirement to have a flexible approach to the onboard command language. The capacity required for OB memory should be defined more precisely. Further consideration should be given to the requirements for: fundamental rasters; short slot high cadence; circular flare buffer; event triggers; 2 CCD data blocks. A clear distinction should be made between what is essential and what is desirable, in order to allocate resources appropriately.
Wednesday morning, November 17
Chair: Jim Lang

Secretary: Ken Dere


Data archiving and database: Tetsuya Watanabe and Len Culhane
Data analysis and software: Dominic Zarro, Bill Thompson, Stein Vidar Haugan



Data archiving and databases



T. Watanabe

Telemetry Data Flow

Command data flow
Need for interface, co-ordination among 3 instruments

Location of databases not decided

Searchable database for locating appropriate data

observer notes

search on spectral lines

L. Culhane


Common Yohkoh software eventually worked well

Solar-B is different and much more complex

Yohkoh: various experiment computers hooked up to SIRIUS database

perhaps the same for Solar-B?


T. Watanabe: uplinks should be possible from all ground stations
J. Davis: how easy will it be to reprogram EIS for real time operations?

H. Mason: Interactive capabilities were not use on SOHO for CDS. Why

and what were the limitations?

B. Thompson: Real time operations requires more human and experiment

time. The planners were and are basically part time.

D. Pike: Real time commanding was not forbidden but rarely used. The

first example was roughly 3 years into the mission.

L. Culhane: responding to events was not given a high priority because

of inconvenience and the inertia in the system.

H. Mason: real time operations may be possible with EIS because of a

more capable onboard computer

S. Myers: staffing levels at ISAS for EIS?

D. Pike: will the planning cycle be daily?

Data Analysis and Software



Dominic Zarro
J. Mariska: on SOHO, each experiment maintained its own database

D. M. (?): each database tends to be very different. A common

database must be designed from the beginning.

B. Thompson: the CDS database consists of 60 MB of metadata. IDL is

perhaps not appropriate since it is not multi-threaded. Only one user

can run at a time. IDL on the net is slow. The Ultraviolet Imaging

Telescope (UIT) IDL library contains database routines. Old SST

routines are moved to the end.

L. Culhane: Is it possible to evolve the SST to use it for Solar-B?

H. Mason: SST distributes and archives software but it doesn't

commission it.


Bill Thompson

Solar Soft Tree

H. Mason: documentation?

L. Harra: documentation at YDAC

D. Zarro: documentation is also at GSFC or at least links to it

B. Thompson: version control done by hand with CDS

J. Mariska: problems with hackers
Stein Vidar Haugen

ITA Oslo would like to do EIS quicklook software

XCFIT fits various line profiles to observed profiles

Can re-use SSWIDL as much as possible for QL SW

Since there is much experience with CDS type data, the whole EIS QL

system could be redesigned

Desired changes would be to use objects and pointers

SST has 10,000 routines

Estimate about 5 man-years to do QL SW for EIS

Wednesday afternoon, November 17
Chair: Len Culhane

Secretary: George Doschek


EIS Science Requirements: Louise Harra

The purpose of this session was to discuss the EIS Science Requirements document prepared by Louise Harra and dated 10 November 1999. A spirited discussion took place which resulted in a revised Science Requirements document, which is now available on the web. There was quite a bit of argument and discussion over the requirements, but a consensus was usually reached on each requirement, or a plan was developed that should lead to a consensus. Quite a few action items were generated, e.g., what are the science cases for slits of different sizes? Responsible individuals were identified for each action item, as well as a closing date. These action items are attached to the revised Science Requirements document. Wordsmithing and parameter selections by a committee of rugged individuals is a slow process, but there was an overall spirit of cooperation that lead to considerable progress.


Below is the Science Requirements Document prepared by Louise Harra from the EIS web site

Science Requirements for Solar-B EIS




I. Major Science Goals



Coronal Heating – to investigate the physical mechanisms responsible for coronal heating in the quiet Sun and active regions
Transient Phenomena – to investigate the physical mechanisms responsible for phenomena such as flares, coronal mass ejections, jets, network brightenings.
Energy Transfer from the Photosphere to the Corona – to investigate the causal relationship between events in the photosphere and the corona.
EIS has the capability, through dynamical and plasma diagnostic measurements to investigate the science goals listed.
II. Science Requirements

  1. Basics

          1. To perform EUV spectroscopy with high spatial and spectral resolution


          2. To perform monochromatic EUV imaging with high temporal resolution.




  1. Pointing and Field of View

          1. To select slot or slot as required. Four slit positions are available with choice of 1”, 2”, 50”, 100” (for flares), short slit (for high time cadence) and multi-slit slot. One of the slits must be removable for calibration purposes.

          2. To point EIS in the E-W direction with coarse pointing in the range of +/- 15’ with an accuracy of +/- 3”

          3. Fine pointing has a range of 0-6’ with an accuracy of 0.3” over a time period of 2 hrs.

  2. Telemetry Issues

          1. To readout the entire contents of one CCD (essential).

          2. To allow any fraction of the CCD to be downloaded (i.e. not the full slit length).

          3. To allow fractions of the CCD to be downloaded (i.e. windowing).

          4. To expose and process (e.g. readout time, scanning mechanisms, compression) data on order of fractions of seconds.

          5. To perform exposure times in the range of 100 ms – few hundred s with an accuracy of 5ms.

          6. To perform data compression.

  3. Mode of Observation

          1. Science operations shall be performed from ground command.

          2. The onboard software should be modular to aid the code development and allows the uplinking of new software.

          3. Dave is re-writing this one!

          4. The instrument shall also collect data based on a number of uplinked observing sequences which are stored (not like SUMER).

          5. The parameters of the observations shall be changed by command.

  4. Event Trigger

          1. To respond or not to XRT’s flare trigger by moving to the flare location and starting a new observing sequence. Only respond if the flare is within the EIS FOV.

          2. To generate an internal EIS solar event trigger. This should have the flexibility to change the study used to define the trigger.

          3. To respond to the event trigger by moving to the event and starting a new study within 5 secs.

          4. To use a cycle buffer to store T-5 mins pre-event data.

  5. Instrument Health

          1. Maintain instrument thermal control at a temperature TBD.

          2. Have the ability to interrupt studies (abort or pause and restart).

          3. Monitor the health of the instrument and enter a safe mode if an anomaly is detected.

          4. The instrument must respond in an appropriate manner to spacecraft emergency, including closing the telescope door.

          5. Perform necessary calibrations (TBD).


Key Terms

Description

Line List

List of chosen spectral lines

Raster

An exposure at several locations

Study

A sequence of rasters

Observation

A study which may be repeated


Task

Person

Finish Date

Investigate science case for 1” and 2” slits

Helen

End of Jan 2000

Investigate science case for 50” and 100” slits

Ken

End of Jan 2000

Investigate science case for multi-slit slot

Joe

End of Jan 2000

Investigate science case for the short slot

Ken

End of Jan 2000

Investigate how many sequences can be run, when they start and for how long

Rob (with input from Dave)

End of Jan 2000

Investigate the maximum number of windows necessary for good line coverage

Dave

End of Jan 2000

Re-write the description of ‘rastering’ in a more variable way

Dave

ASAP

Tidy EIS web site and start a easy access general separate web page

Louise

End of Jan 2000

Investigate the accuracy of coronal coalignment with SXT and CDS

Dave & Louise

Early April 2000


EIS/XRT/FPP Solar-B meeting, November 18-19
Thursday morning, November 18
9:30 Welcome by George Doschek
Chair: John Davis

Secretary: Harry Warren


Description of instruments and observing capabilities
9:40 FPP: Tom Berger/Jake Wolfson

10:10 XRT: Ed Deluca



11:10 EIS: Len Culhane
End-to-end data throughput, J-side view: Tetsuya Watanabe

Tom Berger of LMSAL gave a detailed description of the FPP.
Ed DeLuca – Will the common detector for the Narrowband Filter Imager (NFI) and Broadband Filter Imager (BFI) have a single pixel size? Tom Berger – The current baseline is for a single plate scale, although alternatives are being considered.
George Doschek – Is it possible to trace common elements through these layers [photosphere and chromosphere] of the solar atmosphere? Tom Berger – Yes, for strong elements. It is harder for weaker elements. It is also difficult to do from the ground. Simultaneous images are needed.
John Davis – Can you send down raw images? Tom Berger – Yes.
Ed DeLuca – Are your image processing algorithms changeable from the ground? How much more data is generated if you send all of the images? Tom Berger – Yes, I think they are changeable. About 2-8 times more data is generated if we telemeter all of the data.
Dave Pike – Has the aging of filters in space been studied? Tom Berger – I don’t know.
Len Culhane – Are offsets to the correlation tracker possible? Tom Berger – Yes, we can have an H alpha pointing on the limb and do correlation tracking on the disk.
Ken Dere – Can you do correlation tracking on the granulation? Tom Berger – Yes.
Ed DeLuca of SAO gave a description of the XRT. Kathy Reeves of SAO presented the results of theoretical temperature response functions and mirror reflectivities.
George Doschek – How are you going to get to low temperatures with XRT? Ed DeLuca – Filters that allow longer wavelength emission will be used. These images will also transmit the higher-temperature, short wavelength emission and so differencing will have to be used.
Joe Davila – Have you done any error analysis on the subtraction? Ed DeLuca – Not yet.
John Seely – Is the wavelength range around 300 Angstroms of interest to you? There is a new filter from Luxel that may be of interest to you. Ed DeLuca – We don’t want to image in this wavelength range.
Louise Harra – Could you explain the low temperature response again? Ed DeLuca - Filters that allow longer wavelength emission will be used. These images will also transmit the higher-temperature, short wavelength emission and so differencing will have to be used.
George Doschek – Is the point spread function dependent on wavelength? Ed DeLuca – Yes, the diffraction limit of the telescope is 60 Angstrom.
George Doschek – Have you considered the torques produced by the instrument? Ed DeLuca – Not in detail. Our torques will be much smaller than your torques.
Louise Harra – How many filters will XRT have? Ed DeLuca - There are 12 positions on two filter wheels. Of these, 2 will be open and 10 will contain analysis filters. Some of thinnest filters will have redundant positions.
Len Culhane of MSSL gave a description of the EIS.
Tom Berger – Will EIS have a split coating on the primary mirror? Len Culhane – Yes.
Ed DeLuca – How stable has the calibration for CDS been? Bill Thompson – Considerably, but this reflects errors in the original pre-flight calibration more than a loss in sensitivity. There has also been some burn-in of the stronger lines.
Rock Bush – How will alignment with FPP be achieved? Len Culhane – We should be able to use He II 256 Angstrom. George Doschek – We should also be able to align indirectly using XRT data.
Rock Bush – Has any thermal modeling of the alignment been done? Len Culhane – It is in progress.
Rock Bush – What is the scan rate? Ken Dere - In the quiet Sun, 10s of minutes. In active regions, minutes.
Tetsuya Watanabe of NAOJ gave a description of the Solar-B satellite and the data processing system.
Ed DeLuca – Can the memory allocation for the three instruments be changed on board? Tetsuya Watanabe – Yes.
Ed DeLuca – Will partition 2 be used for analysis of the XRT flare flag images? Tetsuya Watanabe – Yes.
Thursday afternoon, November 18
Chair: John Mariska

Secretary: Louise Harra


Coordinated observing programs
1:40 XRT: Ed Deluca

2:10 FPP: Tom Berger



3:10 EIS: Ken Dere
Co-alignment: Bill Thompson, Ken Dere
Influence of TRACE observations on Solar-B science: Harry Warren

There was an introduction by Len Culhane about the solar B meeting in Japan emphasizing the need to have a well-defined idea of coordinated observations - how the instruments will affect each other and how we can observe most effectively together. The discussion for the afternoon addressed many issues related to this.
Ed DeLuca described various observing modes with XRT (see copies of overheads). They are considering the possibility of running long and short exposures in the same filter in order to extract fainter features. This however would require more onboard memory. This was an issue which was to be brought up several times during the session.
XRT plan to run calibration data at the start of each day using a long and short exposure in each filter. There are 6 filter positions available. All 3 instruments would probably run calibration/synoptic sequences for the same time period. The most controversial issue brought up was the discussion of the preference from the XRT team to point at sun center once every 90 mins (or orbit). This was pointed out to be very restrictive to the other instruments. The scientific reason for carrying out synoptic studies of this nature was accepted by everyone, but a careful assessment needs to be carried out to determine how many times a day it is acceptable to do this. The observation itself takes only 90s, but the spacecraft has to be moved to do this and to return to the same observing point again would prove to be difficult. The general feeling is that most observations that will be carried out will be longer term ones. So the short studies that were carried out for CDS are not preferred ones. This means that since the studies time will be longer will it be acceptable to interrupt them to switch to an XRT synoptic? It would be unacceptable to interrupt a raster sequence in the middle of an observation.
This is quite similar to the MDI synoptic observation requirement. The minimum requirement would be one observation a day. It must be determined how long it would be acceptable to the XRT team to tolerate interruptions in this mode. Since all instruments have to have the same pointing a different philosophy will be required than that of SOHO.
It was agreed that 6X6' is an acceptable FOV of an AR. This followed on from the EIS science requirement on the FOV of EIS. We increased it from 4X4' to 6X6'.
The spacecraft can track solar features. It was unclear as to the step sizes and accuracy of this.
Most of XRTs studies that were described in the overheads would have problems with the onboard memory.
Tom Berger described similar observing sequences for FPP (see overheads). Again there were onboard storage problems for sequences which were standard and forward. It seems that it is maybe possible to increase the pipeline from the FPP to MDP by a factor of 2, but is unlikely that the onboard storage can be changed. It is also hoped that the number of passes per day is increased.
Bill Thompson spoke about co-alignment of CDS with EIT He 304. For solar B coalignment the He from EIS will be used with H alpha on FPP and white light on XRT. There was a discussion on TRACE alignment - the low-lying coronal moss coaligns very well with H alpha. There were problems found with coaligning TRACE and La Palma data when the pointing was away from disk center due to the height differences of the structures.
Caution was expressed about the TRACE/CDS alignment due to the time it takes to make a raster. This is difficult temporally due to the amount of detail and dynamics seen at 1". It is recommended that observers ensure that a context image is taken for coalignment. It would also be helpful if a synchronized alignment dataset from all three instruments was put into the timeline in the planning tool. We need to have time tagged commands. Caution was also registered in doing this with the deadtimes involved. CDS had an error of ~10%.
Simulated coalignment was suggested between the coronal images with SXT and CDS. It is hoped that we can also coalign with the coronal XRT Images and coronal EIS images. Dave P. and Louise will look into this.
Harry Warren spoke about the flare flag on TRACE. TRACE has a preflare buffer with an image taken every 15 s with a buffer of 1000 s. With the TRACE data it is very time-consuming to produce movies within IDL. For FPP analysis using C/C++ coding dynamically linked with IDL will save on memory and is much faster. There is a new version of IDL will allows calls to windows and Unix with C/C++ etc.
Friday morning, November 19
Chair: Jake Wolfson

Secretary: Andrzej Fludra


Planning and operations

Yohkoh: Watanabe

SOHO: Dere
Data archiving, databases and management

SOHO: Zarro

Data analysis and software

Coordinate systems and FITS files: Bill Thompson

Solar Soft Tree: Bill Thompson/Dominic Zarro


Tetsuya Watanabe presented Yohkoh planning and operations (see viewgraph).


Ken Dere presented SOHO planning and operations (viewgraph).
Discussion no. 1:

There is a need to design a common planning tool in IDL for all instruments. The concept of the Instrument Activity Plan (IAP) on SOHO was described - each instrument informs other instruments of its activities. This is only a graphical display and requires human interaction. The difference between SOHO and Solar-B is that all Solar-B instruments point together. How can Solar-B go beyond the SOHO's IAP design?


Jake Wolfson presented Trace planning and operations (viewgraph).
Discussion no. 2:

how to share onboard memory. Possibilities: (1) hard partition, imposing memory limit for each instrument; (2) ability to overwrite other instrument's memory (by agreement). Flare mode has high memory requirements. It was noted that when one instrument exhausts its memory allocation, other instruments are free to change the pointing.


Discussion no 3:

Initiated by the question from the FPP team about the effect of FPP's correlation tracking on other instruments - when the spacecraft has to move, do other instruments need to know about it? Does the s/c move discretely or continuously to keep up with the solar rotation? Tetsuya Watanabe's comments: re-orientation of the s/c will not be done automatically, but only by human intervention. The s/c tracks the sun according to a theoretical equation. The correlation tracker cannot repoint the s/c on its own. Repointing depends on the location of the target (limb, center, etc.).


CONCLUSION: the tracking is continuous, using an analytical curve. The rotation compensation is optional and can be turned off.
Discussion no. 4: idea of the monthly/weekly/daily planning meeting is a good one. Suggested to select a lead instrument for each science plan. There is no limit on the duration of a particular observing plan - depending on the objective, the plan could be even a week-long.
Discussion no.5:

how should observers approach requests for observations, on an instruments basis or a as a general request. Options: (1) all instruments support a given science objective (driven by a joint target); (2) partition the day so that each instrument has freedom to choose a target within its allocated time. The reason is that some instruments may use up their memory allocation and then other instruments can choose a different target.


Discussion no. 6:

data transfer rate. Is there a need for instruments to know when another instrument comes out of its normal observing mode? (Probably not). Event flags (e.g., flare flags): EIS -- XRT. Other flags?


Rolling the s/c is not forseen (the thermal control would be disturbed; there would be a loss of fine pointing because there is only one star tracker looking at the ecliptic South). Polar observations are still possible by pointing the s/c.

Ed DeLuca has volunteered to provide an IDL code to simulate FPP/XRT/EIS observing sequences for which all the instrument teams will provide components.


Dominic Zarro presented Data Analysis and Software (viewgraphs). An example of HESSI database - ground-based information available to search and cross-correlate.
Discussion no. 7:

Possible types of search in the database: time interval, object/target (e.g., all active regions on the limb). Need for human-generated event lists. Assessment of data quality/fulfillment of objectives after observation - can the planner do that if data taken through DSN will take 2-3 days to reach ISAS? Consider a possibility of using a dedicated person to check on the successful observations.


Bill Thompson presented a proposal for "Fits files and coordinate systems" (viewgraphs).
Dominic Zarro: software for data analysis (viewgraph). Based on the concept of solarsoft (an extension will be added). Object-oriented software is more user friendly. Discussion on JAVA and IDL. Encouraged ground-based observatories to use standard FITS keywords.
Final discussion:

Setting up working groups to address the following areas: analysis software, planning tool, database & catalogues, observing and planning, science planning strategy. Team Bulletin Board concept and science management - information on how the data is utilized, who works on which topic/data.




Summary: 'Where do we go from here?'
Next EIS meeting: April at MSSL
In order to determine and meet the scientific goals of Solar-B and to achieve the required level of coordination among the 3 instrument teams it was found useful to set up small working groups to address the following areas:
Analysis software

Observing planning

Scientific Database/Catalog

metadata products



Science management

bulletin board


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