From server@athena.gsfc.nasa.gov Thu May 12 00:59:28 1994 X-VM-Summary-Format: "%n %*%a %-17.17F %-3.3m %2d %4l/%-5c %I\"%s\"\n" X-VM-Labels: nil X-VM-VHeader: ("Resent-" "From:" "Sender:" "To:" "Apparently-To:" "Cc:" "Subject:" "Date:") nil X-VM-Bookmark: 8 Status: RO X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["3538" "Thu" "12" "May" "1994" "00:58" "EDT" "Ian M George, Code 668, NASA/GSFC, USA (Usque ad mortem bibendum)" "GEORGE@heagip.gsfc.nasa.gov" nil "95" "Standard kywrds for energy & channel ranges (OFWG prelim recomm p20.2)" "^From:" nil nil "5" nil nil nil nil] nil) Return-Path: Received: from athena.gsfc.nasa.gov by fits.cv.nrao.edu (4.1/DDN-DLB/1.5) id AA09488; Thu, 12 May 94 00:59:27 EDT Received: by athena.gsfc.nasa.gov (Smail3.1.28.1 #4) id m0q1Squ-0003caa; Thu, 12 May 94 00:58 EDT Message-Id: <940512005830.20e0013b@heagip.gsfc.nasa.gov> Errors-To: oneel@arupa.gsfc.nasa.gov Reply-To: heafits@athena.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas From: "Ian M George, Code 668, NASA/GSFC, USA (Usque ad mortem bibendum)" Sender: server@athena.gsfc.nasa.gov (Listserv/Listproc manager) Sender: heafits@athena.gsfc.nasa.gov To: dwells@fits.CV.NRAO.EDU Subject: Standard kywrds for energy & channel ranges (OFWG prelim recomm p20.2) Date: Thu, 12 May 94 00:58 EDT STANDARD KEYWORDS FOR ENERGY & CHANNEL BOUNDARIES IN DERIVED FILES ------------------------------------------------------------------ At a meeting on 1994 May 11 of the OGIP FITS Working Group (OFWG) there was a review of keywords used to store information relating to the energy & channel ranges used to construct derived products. In an attempt to standardize the various conventions which have been adopted in the past, the OFWG made the following preliminary recommendation. As always, comments from the rest of the community are invited. The OFWG plans to take a final vote on this proposal in a couple of weeks. Ian M George on behalf of the OFWG --------------------------------------------------------------------------- OFWG Prelim Recommendation p20.2 ---------------------------------------------------------------------- | STANDARD KEYWORDS FOR ENERGY & CHANNEL BOUNDARIES IN DERIVED FILES | ---------------------------------------------------------------------- Version: 1994 May 11 Typically, in the FITS header of a 'derived' file (such as an image, a lightcurve or a spectrum), it is desirable to have keywords which carry the information of the channel or energy boundaries/ranges used to select the data. The OFWG recommends that channel and/or energy boundaries be recorded using the following keywords. Channel boundary: ----------------- The keywords to define lower and higher channel bounderies are: CHANMIN = n /n= numeric (integer) value for the lower boundary CHANMAX = m /m= numeric (integer) value for the higher boundary For those experiments which derived files could be created selecting on diffent channel coodinates (eg. PHA or PI), the coodinates type should be specified using the keyword CHANTYPE= 'value' / value=character string {currently the allowed values are 'PHA' and 'PI'} Energy boundary: ---------------- To define the energy range of the data in a derived/product file, the keywords recommended are : E_MIN = n.n /n.n numerical value of the lower energy boudary E_MAX = m.m /m.m numerical value of the higher energy boundary EUNIT = 'keV' /character string for unit of E_MIN and E_MAX {where the string must conform to the rules given in OGIP memo OGIP/93-001} Deprecated Alternatives ----------------------- Within the OGIP a number of files and /or documents have used or defined different keywords to specify energies or channels boundaries. Below is a list of those different/old definitions. These old keywords should no longer be used unless they are required by existing instrument-specific software. It is strongly suggested that any such software be updated to handle the above keywords as soon as possible. a) The memo number OGIP/93-003 defines the keywords MINCHAN and MAXCHAN for the channel boundaries. b) The previous versions of the ROSAT standard processing software (SASS) created images containing the following keywords: XS-CHAN XS-MINCH XS-MAXCH PHACHANS PICHANS MINPI MAXPI MINPHA MAXPHA c) The latest version of the ROSAT standard processing software (SASS) creates images where the above 9 keywords have been replaced by PIMIN PIMAX in the case of PSPC instrument PHAMIN PHAMAX in the case of HRI instruments. ----------------------------------- END ---------------------------------- Ian M George NASA/GSFC OFWG 1994 May 11 From server@athena.gsfc.nasa.gov Fri May 20 04:15:51 1994 Status: RO X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1477" "Fri" "20" "May" "1994" "04:13" "EDT" "Morten Krabbe Barfoed" "morten@copernicus.dsri.dk" nil "45" "TELESCOP-keyword." "^From:" nil nil "5" nil nil nil nil] nil) Return-Path: Received: from athena.gsfc.nasa.gov by fits.cv.nrao.edu (4.1/DDN-DLB/1.5) id AA05127; Fri, 20 May 94 04:15:49 EDT Received: by athena.gsfc.nasa.gov (Smail3.1.28.1 #4) id m0q4Pi7-0003kVa; Fri, 20 May 94 04:13 EDT Message-Id: <9405200814.AA28119@copernicus.dsri.dk.dsri.dk> Errors-To: oneel@arupa.gsfc.nasa.gov Reply-To: heafits@athena.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas From: morten@copernicus.dsri.dk (Morten Krabbe Barfoed) Sender: server@athena.gsfc.nasa.gov (Listserv/Listproc manager) Sender: heafits@athena.gsfc.nasa.gov To: dwells@fits.CV.NRAO.EDU Subject: TELESCOP-keyword. Date: Fri, 20 May 94 04:13 EDT I have just read some of the old comments on the use of the TELESCOP-keyword to denote the name of the mission, and I've also found it to be rather badly chosen. I have a suggestion that might easy the pain: 1: Introduction of a new keyword (OBSERVAT and SATELLIT have been suggested, MISSION could perhaps be used as well). 2: The value given to this keyword should be identical to the value given to the TELESCOP-keyword. Thus, you could have: SATELLIT='ROSAT ' TELESCOP='ROSAT ' INSTRUME='PSPCC ' .... This would be a soft introduction to a new keyword denoting the mission, and would not interfere with old software. A suggestion for the next step: iff the SATELLIT-keyword is present, then TELESCOP denotes telescope, INSTRUME detector and so on, and iff SATELLIT is not present, then the old usage prevails. I'm not sure whether this kind of scheme is used at all when dealing with FITS-files. It's not trouble- free, but I guess, that programs to read FITS-files change whereas the old FITS-files from completed missions keep their format. The above would complicate software-develope- ment but would not put demands on the format of old FITS-files. Comments are invited. Best regards to all: Morten Krabbe Barfoed Danish Space Research Institute phone: +45 42 88 22 77 (switch-board) Gl. Lundtoftevej 7 phone: +45 45 87 40 77 - 161 (direct) DK 2800 Lyngby FAX: +45 45 93 02 83 Denmark TELEX: 37 198 e-mail: morten@dsri.dk From server@athena.gsfc.nasa.gov Fri May 20 04:58:52 1994 Status: RO X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["742" "Fri" "20" "May" "1994" "04:56" "EDT" "Clive Page" "cgp@star.le.ac.uk" nil "19" "Re: TELESCOP-keyword." "^From:" nil nil "5" nil nil nil nil] nil) Return-Path: Received: from athena.gsfc.nasa.gov by fits.cv.nrao.edu (4.1/DDN-DLB/1.5) id AA05134; Fri, 20 May 94 04:58:51 EDT Received: by athena.gsfc.nasa.gov (Smail3.1.28.1 #4) id m0q4QNl-0003kVa; Fri, 20 May 94 04:56 EDT Message-Id: Errors-To: oneel@arupa.gsfc.nasa.gov Reply-To: heafits@athena.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas From: Clive Page Sender: server@athena.gsfc.nasa.gov (Listserv/Listproc manager) Sender: heafits@athena.gsfc.nasa.gov To: dwells@fits.CV.NRAO.EDU Subject: Re: TELESCOP-keyword. Date: Fri, 20 May 94 04:56 EDT I'd support the suggestion of Morten Krabbe Barfoed that the original 'TELESCOP' keyword is a bit inadequate for complex space missions. But perhaps I can point out that his example is a bit ill-chosen precisely because you DO need three different keywords in this case. ROSAT has two telescopes: the Wide Field Camera (WFC) [from the UK] and the X-ray Telescope (XRT) from Germany, the latter with two detectors (PSPC and HRI). Thus to specify your observation completely you would need something like: SATELLIT='ROSAT ' TELESCOP='XRT ' INSTRUME='PSPC ' .... ! Clive Page, Dept of Physics & Astronomy, University of Leicester, UK. ! e-mail: cgp@star.le.ac.uk ! phone: +44 533 523551 Fax: +44 533 550182 From server@athena.gsfc.nasa.gov Fri May 20 06:19:39 1994 Status: RO X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1541" "Fri" "20" "May" "1994" "06:17" "EDT" "Morten Krabbe Barfoed" "morten@copernicus.dsri.dk" nil "48" "TELESCOP-keyword." "^From:" nil nil "5" nil nil nil nil] nil) Return-Path: Received: from athena.gsfc.nasa.gov by fits.cv.nrao.edu (4.1/DDN-DLB/1.5) id AA06332; Fri, 20 May 94 06:19:38 EDT Received: by athena.gsfc.nasa.gov (Smail3.1.28.1 #4) id m0q4Rdw-0003cha; Fri, 20 May 94 06:17 EDT Message-Id: <9405200914.AA28287@copernicus.dsri.dk.dsri.dk> Errors-To: oneel@arupa.gsfc.nasa.gov Reply-To: heafits@athena.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas From: morten@copernicus.dsri.dk (Morten Krabbe Barfoed) Sender: server@athena.gsfc.nasa.gov (Listserv/Listproc manager) Sender: heafits@athena.gsfc.nasa.gov To: dwells@fits.CV.NRAO.EDU Subject: TELESCOP-keyword. Date: Fri, 20 May 94 06:17 EDT Commenting on my earlies suggestion, Clive Page writes: . I'd support the suggestion of Morten Krabbe Barfoed that the original . 'TELESCOP' keyword is a bit inadequate for complex space missions. But . perhaps I can point out that his example is a bit ill-chosen precisely . because you DO need three different keywords in this case. ROSAT has two . telescopes: the Wide Field Camera (WFC) [from the UK] and the X-ray . Telescope (XRT) from Germany, the latter with two detectors (PSPC and . HRI). Thus to specify your observation completely you would need . something like: .. . SATELLIT='ROSAT ' . TELESCOP='XRT ' . INSTRUME='PSPC ' . .... Well, perhaps I've expressed myself badly. I simply used an RDF-file taken from the legacy-server. That file contains among other things the following keywords: TELESCOP='ROSAT ' INSTRUME='PSPCC ' The essence of the suggestion is the introduction of a new keyword, that contains the same information as the TELESCOP-keyword, without altering the usage of the TELESCOP-keyword. The result would be: SATELLIT='ROSAT ' TELESCOP='ROSAT ' INSTRUME='PSPCC ' - not changing the current description of mission, telescope, detectors and so on, only adding one keyword, that contains redundant information. Best regards: Morten Krabbe Barfoed Danish Space Research Institute phone: +45 42 88 22 77 (switch-board) Gl. Lundtoftevej 7 phone: +45 45 87 40 77 - 161 (direct) DK 2800 Lyngby FAX: +45 45 93 02 83 Denmark TELEX: 37 198 e-mail: morten@dsri.dk From server@athena.gsfc.nasa.gov Fri May 20 08:40:40 1994 Status: RO X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["496" "Fri" "20" "May" "1994" "08:38" "EDT" "Arnold Rots" "arots@xebec.gsfc.nasa.gov" nil "12" "Re: TELESCOP-keyword." "^From:" nil nil "5" nil nil nil nil] nil) Return-Path: Received: from athena.gsfc.nasa.gov by fits.cv.nrao.edu (4.1/DDN-DLB/1.5) id AA06484; Fri, 20 May 94 08:40:39 EDT Received: by athena.gsfc.nasa.gov (Smail3.1.28.1 #4) id m0q4TqP-0003cxa; Fri, 20 May 94 08:38 EDT Message-Id: <199405201239.IAA20152@xebec.gsfc.nasa.gov> Errors-To: oneel@arupa.gsfc.nasa.gov Reply-To: heafits@athena.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas From: Arnold Rots Sender: server@athena.gsfc.nasa.gov (Listserv/Listproc manager) Sender: heafits@athena.gsfc.nasa.gov To: dwells@fits.CV.NRAO.EDU Subject: Re: TELESCOP-keyword. Date: Fri, 20 May 94 08:38 EDT I am not so sure I support Morten's suggestion. However, if the sense of the community is that there is a strong need for another keyword, then I would, equally strongly, suggest that we not be parochial about it and, rather than SATELLIT, adopt some abbreviation (damn eight character limit!) of OBSERVATORY, like OBSVTORY. It has a wider meaning and application in astronomomy, it is an intuitive match, and, as a matter of fact, it has been used in that sense (e.g., GRO). - Arnold Rots From server@athena.gsfc.nasa.gov Fri May 20 09:58:11 1994 Status: RO X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["5440" "Fri" "20" "May" "1994" "09:55" "EDT" "Lucio Chiappetti" "lucio@ifctr.mi.cnr.it" nil "122" "Re: TELESCOP-keyword." "^From:" nil nil "5" nil nil nil nil] nil) Return-Path: Received: from athena.gsfc.nasa.gov by fits.cv.nrao.edu (4.1/DDN-DLB/1.5) id AA06551; Fri, 20 May 94 09:58:08 EDT Received: by athena.gsfc.nasa.gov (Smail3.1.28.1 #4) id m0q4V3N-0003aEa; Fri, 20 May 94 09:55 EDT Message-Id: Errors-To: oneel@arupa.gsfc.nasa.gov Reply-To: heafits@athena.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas From: Lucio Chiappetti Sender: server@athena.gsfc.nasa.gov (Listserv/Listproc manager) Sender: heafits@athena.gsfc.nasa.gov To: dwells@fits.CV.NRAO.EDU Subject: Re: TELESCOP-keyword. Date: Fri, 20 May 94 09:55 EDT I do not see any reason the change the usual practice by which the TELESCOP keyword denotes the satellite mission. Since this is hardly relevant for software, the simplest thing is not to touch the existing standard (TELESCOP is one of the early "reserved" keyword). Actually in my s/w (which uses a local non-FITS FITS-like format) I use a SATELLIT keyword for this purpose. But I convert it to TELESCOP when I write out my files in FITS. That seemed to me the simplest solution. There are already three keywords to determine the instrument data are taken from, TELESCOP, INSTRUME and DETNAM (the first two are part of the "reserved" keywords; I do not particularly like DETNAM from an aesthetic point of view, I'd preferred an 8-char-English-word like DETECTOR, but since it is in widespread use I abide to it). I would not be concerned by the fact that some satellites may host a variety of actual "telescopes" (i.e. optics systems), some of which may have a variety of instrument in the focus. There also cases in which there is no optics at all, i.e. no "telescope". It is just a matter of names, this is how I'll see it : TELESCOP (SATELLIT) indicates the spacecraft INSTRUME indicates the complex of optics (when present) and instrument (if the association is fixed) DETNAM indicates the sub-unit of a multi-unit detector, or the detector in focus when this can be interchanged I'll make some examples : TELESCOP EXOSAT INSTRUME LE1 or LE2 one of two optics systems DETNAM CMA or PSD each of the two telescopes had the possibility of having in focus one of two detectors (they were on a moveable mechanism) TELESCOP EXOSAT INSTRUME ME a collimated proportional counter array DETNAM ggn (consisting of 8 Argon detectors Ar1 to Ar8 and 8 Xenon detectors Xe1 to Xe8; in addition one could also use combinations in quadrants and halves) TELESCOP EXOSAT INSTRUME GSPC a collimated GSPC (no need of DETNAM) TELESCOP SAX INSTRUME LECS one optics system + one GSPC in focus TELESCOP SAX INSTRUME MECS one electronics controller ... with DETNAM Mn three separate GSPCs (M1 M2 M3) in focus of three separate optics systems this is tricky, may be I would use instead TELESCOP SAX INSTRUME Mn and forget DETNAM; Mn indicates the combina- tion of optics and detector, and neglects the fact a single processor handles all 3 TELESCOP SAX INSTRUME HPGSPC one collimated GSPC (no need of DETNAM) TELESCOP SAX INSTRUME PDS one collimated phoswich, consisting of DETNAM Pn 4 sub-units (may also be used in couples) TELESCOP SAX INSTRUME WFCn one of two coded-mask wide field cameras (looking in opposite directions) TELESCOP XMM INSTRUME EPIC1 (or MOS1) a CCD array in focus of telescope 1 DETNAM CHIPn consisting of 7 chips TELESCOP XMM INSTRUME EPIC3 (or MAXI, or PN1), a CCD array in focus of telescope 3, uses a different technology DETNAM CHIPn consisting of 12 chips TELESCOP XMM INSTRUME EPIC2 either MOS2 or PN2, a CCD array equal to one of the previous, in focus of telescope 2 DETNAM CHIPn TELESCOP XMM INSTRUME RGS1 a CCD detector placed after a reflection grating sharing the beam of telescope 1 INSTRUME RGS2 idem, in the beam of telescope 2 (telescope 3 is unobstructed) In this latter example one sees that the same "telescope" has two permanently mounted instruments. It is hardly relevant to have a separate keyword to denote the optics systems. Disclaimer: The examples are made on real cases I work or had worked with. The names used are indicative and in the case of Exosat may not correspond to what is used in current archives, while in the case of SAX and XMM are just representative (although in a few cases correspond to conventions I am privately using in simulation software). If it could be of any use, I would accept to have a SATELLIT keyword duplicating the content of the TELESCOP keyword, and denoting the spacecraft. ---------------------------------------------------------------------------- A member of G.ASS : Group for Astronomical Software Support ---------------------------------------------------------------------------- Lucio Chiappetti - IFCTR/CNR | Ma te' vugl' da' quost avis a ti' Orsign via Bassini 15 - I-20133 Milano | Buttet rabios intant te se' pisnign Internet: LUCIO@IFCTR.MI.CNR.IT | Decnet: IFCTR::LUCIO | (Rabisch, II 46, 119-120) ---------------------------------------------------------------------------- From server@athena.gsfc.nasa.gov Fri May 20 10:37:21 1994 Status: RO X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["326" "Fri" "20" "May" "1994" "10:35" "EDT" "BARRY M. SCHLESINGER" "BSCHLESINGER@NSSDCA.GSFC.NASA.GOV" nil "7" "Re: TELESCOP-keyword." "^From:" nil nil "5" nil nil nil nil] nil) Return-Path: Received: from athena.gsfc.nasa.gov by fits.cv.nrao.edu (4.1/DDN-DLB/1.5) id AA06639; Fri, 20 May 94 10:37:16 EDT Received: by athena.gsfc.nasa.gov (Smail3.1.28.1 #4) id m0q4VfG-0003YJa; Fri, 20 May 94 10:35 EDT Message-Id: <940520103652.24200284@NSSDCA.GSFC.NASA.GOV> Errors-To: oneel@arupa.gsfc.nasa.gov Reply-To: heafits@athena.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas From: "BARRY M. SCHLESINGER" Sender: server@athena.gsfc.nasa.gov (Listserv/Listproc manager) Sender: heafits@athena.gsfc.nasa.gov To: dwells@fits.CV.NRAO.EDU Subject: Re: TELESCOP-keyword. Date: Fri, 20 May 94 10:35 EDT I would note that the question of which keywords to use for the mission and experiments is not purely a high energy astrophysics issue but has generalized applicability for space astronomy. It might be useful to discuss this question on fitsbits (sci.astro.fits). Barry Schlesinger NSSDC/NOST FITS Support office From server@athena.gsfc.nasa.gov Fri May 20 11:50:37 1994 Status: RO X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["2155" "Fri" "20" "May" "1994" "11:48" "EDT" "Jeff Bloch" "jbloch@sstcx1.lanl.gov" nil "62" "Re: TELESCOP-keyword." "^From:" nil nil "5" nil nil nil nil] nil) Return-Path: Received: from athena.gsfc.nasa.gov by fits.cv.nrao.edu (4.1/DDN-DLB/1.5) id AA06836; Fri, 20 May 94 11:50:36 EDT Received: by athena.gsfc.nasa.gov (Smail3.1.28.1 #4) id m0q4WoF-0003ZNa; Fri, 20 May 94 11:48 EDT Message-Id: Errors-To: oneel@arupa.gsfc.nasa.gov Reply-To: heafits@athena.gsfc.nasa.gov Originator: heafits@athena.gsfc.nasa.gov Precedence: bulk X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas From: Jeff Bloch Sender: server@athena.gsfc.nasa.gov (Listserv/Listproc manager) Sender: heafits@athena.gsfc.nasa.gov To: dwells@fits.CV.NRAO.EDU Subject: Re: TELESCOP-keyword. Date: Fri, 20 May 94 11:48 EDT I'm confused about suggestion #2 in the message below. What about data from the ROSAT satellite using the WFC telescope???? -------------------------------------------------------------------------- Jeffrey Bloch Office: (505) 665-2568 Astrophysics and Radiation Measurements Group ALEXIS Soc: (505) 665-5975 Los Alamos National Laboratory FAX: (505) 665-4414 Group NIS-2, Mail Stop D436 e-mail: jbloch@lanl.gov Los Alamos, NM 87545 -------------------------------------------------------------------------- On Fri, 20 May 1994, Morten Krabbe Barfoed wrote: > I have just read some of the old comments on the use of the > TELESCOP-keyword to denote the name of the mission, and I've > also found it to be rather badly chosen. > > I have a suggestion that might easy the pain: > > 1: Introduction of a new keyword (OBSERVAT and SATELLIT > have been suggested, MISSION could perhaps be used as > well). > > 2: The value given to this keyword should be identical > to the value given to the TELESCOP-keyword. > > Thus, you could have: > > SATELLIT='ROSAT ' > TELESCOP='ROSAT ' > INSTRUME='PSPCC ' > .... > > This would be a soft introduction to a new keyword denoting > the mission, and would not interfere with old software. > > A suggestion for the next step: iff the SATELLIT-keyword is > present, then TELESCOP denotes telescope, INSTRUME detector > and so on, and iff SATELLIT is not present, then the old > usage prevails. I'm not sure whether this kind of scheme is > used at all when dealing with FITS-files. It's not trouble- > free, but I guess, that programs to read FITS-files change > whereas the old FITS-files from completed missions keep > their format. The above would complicate software-develope- > ment but would not put demands on the format of old FITS-files. > > Comments are invited. > > Best regards to all: > > Morten Krabbe Barfoed > > Danish Space Research Institute phone: +45 42 88 22 77 (switch-board) > Gl. Lundtoftevej 7 phone: +45 45 87 40 77 - 161 (direct) > DK 2800 Lyngby FAX: +45 45 93 02 83 > Denmark TELEX: 37 198 > > e-mail: morten@dsri.dk >