Changes between Initial Version and Version 1 of DataModel18beta


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Timestamp:
11/16/21 12:51:22 (2 years ago)
Author:
alisdair
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  • DataModel18beta

    v1 v1  
     1= VSO Data Model - Version 1.8beta = 
     2 
     3This version of the data model is '''CURRENTLY''' being worked on to update it to what is actually being used. 
     4 
     5== Introduction == 
     6The VSO Data Model provides a set of template descriptions for information required to describe, access, and search solar data sets in a variety of archives. It is an abstract model, not a suggested set of keywords to be used in data nor in databases. Because of the ubiquity of the FITS standard and the wide use of certain conventions, we provide illustrative values of FITS keywords for certain data elements; but neither the adoption of any set of particular keywords nor the FITS data model at all are required for a data description to conform to the model. The VSO Element Names, are used at a level of abstraction once removed from the search parameters of the data providers. They should be completely internal to the VSO procedures for decoding information from user interfaces, not sent in in queries to data providers. We have deliberately avoided the use of FITS-compatible keyword names to emphasize this point. 
     7 
     8== VSO Search Parameters == 
     9VSO search parameters are those data descriptors for which queries are supported by the VSO in behalf of client applications or requests. These are the parameters that can best discriminate among a large collection of heterogeneous data. They must therefore be supported by the data providers as search parameters applicable to a large subset of the data archives. They must map to parameters in the server data dictionaries in a well-defined and meaningful way. They must also be selected so that the number of data sets meeting a particular selection criterion is small compared to the total number: for the VSO an astronomical type search parameter of Object (Sun) is not particularly useful as a discriminator.  
     10The VSO search parameters are divided into a few groups, each described under one of the major subsections. These categories are understood to be orthogonal, in the sense that they can be used to construct non-trivial AND queries. Of course they are not strictly orthogonal: selection of a particular data source (instrument) may automatically restrict the available observing times for example, and vice-versa. Nonetheless it is useful to treat the major categories as if they were orthogonal and treat any dependencies as implicit selections or limits.  
     11No particular set of search parameters is required. In the absence of a relevant element or group of elements in its data description, a dataset is assumed to match all queries. For example, if no wavelength information is supplied, then the server will return all records for any selected (or deselected) wavelength interval. If a parameter is not searchable but has a default value, then that value can be supplied directly in the data description. For example, an archive of data all taken at the same wavelength is unlikely to have wavelength as a searchable key in its database, but could (and should) supply that wavelength as a fixed value in its data description to avoid inappropriate satisfaction of client queries.  
     12The current parameter list is not intended to be exhaustive, and it may be useful to add additional search elements and categories in future. The categories chosen are those for which the VSO either has attempted to implement a search service or contemplates doing so. So far, only a few of the parameters can be searched in the VSO, and these are marked with asterisks in the following list. The elements are described in detail by group under the following sections.  
     13         
     14* [https://docs.virtualsolar.org/wiki/ObservingTime Observing Time]  
     15  * Observation_Time*  
     16  * Duration  
     17  * Time_Step  
     18* [https://docs.virtualsolar.org/wiki/TargetLocation Target Location]  
     19  * Observation_Center_West  
     20  * Observation_Center_North  
     21  * Bounding_Radius  
     22* [https://docs.virtualsolar.org/wiki/ObserverLocation Observer Location]  
     23* [https://docs.virtualsolar.org/wiki/SpectralRange Spectral Range] 
     24  * Wave_Type  
     25  * Wave_Bands (may be deleted in future versions)  
     26  * Wave_Minimum*  
     27  * Wave_Maximum*  
     28  * Wave_Step delete?  
     29* [https://docs.virtualsolar.org/wiki/PhysicalObservable Physical_Observable*] 
     30* [https://docs.virtualsolar.org/wiki/DataOrganization Data Organization] 
     31* [https://docs.virtualsolar.org/wiki/WaveModeSampling Wave Mode Sampling] 
     32  * Degree_Minimum  
     33  * Degree_Maximum  
     34  * Degree_Step delete?  
     35* [https://docs.virtualsolar.org/wiki/DataSource Data Source]  
     36  * Observatory*  
     37  * Instrument*  
     38  * Provider* 
     39  
     40== 1. Observing Time == 
     41Observing time is by general consensus the most likely parameter to be used as a first case for searches, the most ubiquitous indexing parameter for data, and one on which there is widespread agreement and understanding of representations, scales, and units. Most of the complexity involved is in the descriptions of data translation. Here it is sufficient to specify a simple uniform description. \\ 
     42(Most observational data are expected to be associated with observing times, and so far all VSO query structures have been assumed to include a time search parameter. It is possible however that some data may not be; model data are an example. As described above, such data would automatically satisfy any time interval query, and at least one additional parameter would be required to make them selectable.)  
     43 
     44'''Observation_Time''' \\  
     45   type: //time// \\ 
     46   FITS keyword: //T_OBS//\\  
     47   The time at which the data comprising an atomic data set were originally recorded. If the duration of the data in the atomic data unit is large compared with the search time resolution, the Observation_Time is to be understood to correspond to the center (mid-point) of the observation(s), weighted as appropriate. For purposes of the Data Model, Observation_Time is given in calendar-clock form, e.g.2004.03.08_16:25. Times are assumed to be UTC. The time resolution is one minute, so for much data the conversion from say start time of an exposure to Observing_Time should not matter. Likewise the conversions between UTC and other units such as ET, TAI, and GPS should not be a matter of much concern. A data match is assumed to include all data from 30 seconds before the target time to 30 seconds after, inclusive (closed at both ends), so that a data Observation_Time can in principle fall into two adjacent target times. Note that since Jan 1, 1999, TAI = UTC + 32 sec, and GPS = UTC + 13 sec.  
     48 
     49'''Duration''' \\ 
     50   type: //number// \\ 
     51   unit: //second// \\ 
     52   FITS keyword: //T_LENGTH// \\  
     53   The interval between the start and end of observation in the atomic data unit. For a single image or spectrum, this is simply the exposure time; for a movie, it is the time difference between the start of the first image and the end of the last. 
     54 
     55'''Time_Step''' \\ 
     56   type: //number// \\ 
     57   unit: //second// \\ 
     58   FITS keyword: //T_STEP// \\ 
     59   The interval between succesive time samples (data records) in a dataset. \\ 
     60 
     61== 2. Target Location == 
     62Target location, by which is meant the spatial location of the target region of imaged or pointed observations on or around the Sun or in the heliosphere, has not yet been built into any VSO query models, although it is a fairly natural selection criterion for observations with a restricted field of view. It may suffice to specify a simple uniform description, although the multi-dimensionality of space makes this harder than one for time. For two-dimensional image data we assume a bounding circle as the simplest model. For this model it is sufficient to specify the center location and radius of the bounding circle. Most real image data are actually described by a bounding rectangle, but this requires specifying at least five parameters (e.g. the coordinates of opposite corners and a position angle).  
     63 
     64'''Observation_Center_West''' \\  
     65   type: //number// \\ 
     66   unit: //arc-second// \\ 
     67   FITS keyword: //CENT_WST// \\ 
     68 
     69'''Observation_Center_North''' \\  
     70   type: //number// \\ 
     71   unit: //arc-second// \\ 
     72   FITS keyword: //CENT_NRT// \\  
     73   A pair of coordinates specifying the location of the center of the image data circle with respect to the Earth-Sun line at the nominal Observation_Time. This origin is close to the center of the apparent solar image for Earth-based or near-Earth observers, but not necessarily for deep space observations. The North coordinate is measured in the direction of the Carrington axis (RA 286°.13, δ 63°.87 J2000.0), and the West coordinate in the direction of solar rotation.  \\ 
     74 
     75'''Bounding_Radius''' \\  
     76   type: //number// \\ 
     77   unit: //arc-second// \\ 
     78   FITS keyword: //R_BOUND// \\ 
     79   The radius of the bounding circle about the Observation_Center. For the VSO Data Model the bounding circle is to be understood as either the maximum inscribed circle in the bounding data rectangle (polygon), or the minimum circumscribed circle, depending on whether the query is for included data (presumably the normal default) or excluded data, respectively.  
     80 
     81== 3. Observer Location == 
     82No Search Parameters have been defined to describe observer location. Two classes of description are appropriate, one for ground-based observations and one for space-based data, particularly in situ measurements. For Earth observatories, a straightforward geographic latitude / longitude / altitude description should suffice, but it is not clear how useful this would be as a discriminator for data searches. For space platforms, where the description of location for in situ data is especially important, we defer to the model (to be) adopted by the VSPO. It should be noted, though, that as stereoscopic imaging of the Sun from space observatories becomes more important, search parameters associated with observer location with respect to solar coordinate frames may have to be introduced. \\ 
     83 
     84== 4. Spectral Range == 
     85The electromagnetic wavelength interval or equivalent over which observations are made is the fundamental discriminator among many types of solar image and other data. The model needs to apply to both narrow-band ("monochromatic" or single-line) and broad-band data. Different branches of the field use different units depending on their spectral band -- frequency at the lowest ranges (of frequency), wavelength at intermediate ranges, energy at the highest. Again for the sake of simplicity we define a single model, assuming that the necessary conversions can be simply made.  
     86 
     87'''Wave_Type''' \\ 
     88   type: //menu// \\ 
     89   FITS keyword: //WV_TYPE// \\  
     90   The class of spectral data, relating to both the nominal spectral bandpass and the spectral target. Three values are recognized: \\ \\ 
     91   '''broad''' 
     92         Indicates that the spectral range of the measurement is large compared to the width of absorption/emission lines within the range, and encompasses multiple lines as well as continuum (unless blanketed).\\ 
     93   '''line''' 
     94         The spectral range of the measurement is of the same order or less than the width of the target line, and is centered on a wavelength within the wings of the line. \\  
     95   '''narrow''' 
     96         The spectral range of the measurement is of the same order or less than the typical width of lines in the neighborhood, but is centered on a continuum wavelength, outside of any significant lines. This designation is used to distinguish narrow-band continuum (or "white-light") data from true broad-band data. For data of this description, the matching spectral range should be much broader than the instrumental bandpass, on the understanding that the data are proxies for broadband measurements. \\ 
     97The exact definition of the bandpass (e.g. FWHM) is not prescribed, but is left up to the terminology of the data provider. In the absence of a provider definition, FWHM should be used. \\ 
     98 
     99'''Wave_Minimum''' \\  
     100   type: //number// \\ 
     101   unit: //Ångström (10nm)// \\  
     102   FITS keyword: //WV_MIN// \\ 
     103 
     104'''Wave_Maximum''' \\  
     105   type: //number// \\ 
     106   unit: //Ångström (10nm)// \\  
     107   FITS keyword: //WV_MAX// \\ 
     108   The nominal minimum (maximum) of the observing spectral bandpass associated with the data. As discussed above, for narrowband continuum data, the range should be much larger than the instrumental bandpass; it should correspond to the spectral range over which the data are useful as a proxy, typically an octave or more. \\ 
     109 
     110'''Wave_Bands''' \\  
     111   type: //number// \\ 
     112   FITS keyword: //WV_NBAND// \\  
     113   The number of wavelength bands in the observation \\ \\ 
     114  
     115'''Wave_Step''' \\  
     116   type: //number// \\ 
     117   unit: //Ångström (10nm) / pixel// \\ 
     118   FITS keyword: //WV_STP// \\ 
     119   The spectral dispersion\\ 
     120  
     121== 5. Observable == 
     122It is in the description of the independent variables, what the data in fact measure, that there is the greatest variation in terminology among data archives. Most solar observational data consist of direct measurements of the intensity of radiation as a function of time, direction (location), wavelength, and polarization, or combinations of intensities associated with different independent variables (e.g. line shifts and splittings, Stokes parameters). These data may be interpreted as measurements of certain physical observables, such as temperature, velocity, emission measure, etc. via models. There are of course some important exceptions: some solar data archives include in situ measurements of such observables as particle fluxes and compositions and magnetic field strengths; some solar data sets represent not direct observation but the results of complex inversions or modeling, such as the frequencies of acoustic modes, or the interior structure; and there are catalogs, histories, and descriptions of features and events. As long as the various observable classes are orthogonal, however, these additional cases should present no problem.  
     123 
     124The model of describing observables in terms of particular combinations of intensity measurements or the associated physical parameters to be derived from them is a natural one for data deriving from imaging spectrographs, such as magnetographs and helioseismic instruments. For cameras or radiometers measuring only intensity or flux at selected wavelengths, it is not so natural. People dealing with data from such instruments tend to think of the observables as being associated with the spectral wavelength or band selected, or for monochromatic instruments, even the spatial-temporal target of the observations. It is important to understand that the meaning of the term "observable" in the VSO Search Parameter model may not at all agree with the meaning of the term as used by the data providers.  
     125 
     126'''Physical_Observable''' \\  
     127   type: //menu// \\ 
     128   FITS keyword: //PHYS_OBS// \\  
     129   The following values are currently recognized: \\ \\ 
     130   '''intensity'''  
     131         the direct intensity, either integrated over the spectral observing range or as a function of wavelength (spectral density)  
     132   '''equivalent_width''' 
     133         differences between intensities measured at nearby wavelengths, typically in line cores, wings, and nearby continuum, whether measured as an intensity difference or an equivalent width  
     134   '''polarization_vector'''  
     135         the net linear polarization  
     136   '''LOS_magnetic_field''' 
     137         the frequency/wavelength Zeeman splitting between opposite circular polarizations of a magnetically-sensitive line  
     138   '''vector_magnetic_field'''  
     139         field strengths and directions inferred from Stokes polarimetry 
     140   '''LOS_velocity'''  
     141         the displacement of line center from rest wavelength/frequency in an arbitrary polarization state  
     142   '''vector_velocity'''  
     143         Two- or three-dimensional velocities, typically inferred from helioseismic inversion or from directly measured velocities transverse to the line of sight, possibly combined with Doppler velocities  
     144   '''wave_power''' \\ 
     145   '''wave_phase''' \\ 
     146   '''oscillation_mode_parameters''' \\ 
     147         These all refer to solar internal or atmospheric acoustic-gravity wave measurements. The mode parameters could include frequencies, splittings, amplitudes, widths, etc.  
     148   '''number_density''' \\ 
     149   '''particle_flux''' \\ 
     150   '''composition'''\\ 
     151   '''particle_velocity'''\\  
     152   '''thermal_velocity''' \\ 
     153        in-situ observations 
     154  
     155In addition to the above, the following classes have been suggested:  
     156* Electric Field Strength - the Stark effect splitting  
     157* Transverse Magnetic Field Strength - Hanle effect measurements  
     158* Stokes Parameters (I, Q, U, V - equivalent to observables of net circular, linear and total polarization, and polarization angle  
     159* //in situ// Magnetic Field  
     160* Differential Emission Measure  
     161* Model Parameters - Interior, Atmosphere, Solar Wind  
     162 
     163== 6. Data Organization == 
     164The data organization describes the physical meaning of the independent variable(s) with respect to which the observables are measured. This is useful for knowing whether and how different data sets can be directly compared, overlaid, mapped, or otherwise transformed. \\ \\ 
     165'''Data_Layout''' \\  
     166   type: //menu// \\ 
     167   FITS keyword: //DATA_ORG// \\  
     168   The following values are recognized: \\ \\ 
     169   '''image'''  
     170         data organized by two dimensions corresponding to angular displacement along the axes; examples include photograms (digital or digitized photographs), spectroheliograms, magnetograms, and Dopplergrams  
     171   '''map'''  
     172         data organized by two dimensions corresponding to spatial displacement along the axes; examples include synoptic charts  
     173   '''time_series'''  
     174         data organized by one dimension corresponding to temporal displacement along the axis; note that this is not the same as a time-tagged set of data records, since it implies sampling uniformity and provision for data gaps  
     175   '''movie'''  
     176         data organized by three dimensions corresponding to spatial or angular displacement along two axes and temporal displacement along the principal (most slowly varying) axis  
     177   '''spectrum'''  
     178         data organized by one dimension corresponding to displacement in electromagnetic wavelength or frequency along the axis  
     179   '''mode_spectrum'''  
     180         data organized by one or more dimensions corresponding to the quantum numbers of oscillations  
     181   '''spectral_temporal'''  
     182         data organized by two dimension corresponding to displacement in wavelength or frequency along one axis and temporal displacement along the other  
     183   '''spatial_spectral'''  
     184         data organized by two dimensions corresponding to spatial or angular image axes and one corresponding to electromagnetic spectral displacement  
     185 
     186== 7. Wave Mode Sampling == 
     187 
     188These parameters relate to data sets derived from helioseismic analysis of solar image data, specifically to global-mode analysis. No such data sets are currently available from any of the providers, so these search parameters have not yet been implemented. \\ \\ 
     189'''Degree_Minimum''' \\ 
     190   type: //number// \\ 
     191   FITS keyword: //L_MIN// \\  
     192'''Degree_Maximum''' \\ 
     193   type: //number// \\ 
     194   FITS keyword: //L_MAX// \\  
     195   The nominal minimum (maximum) of the spherical harmonic degree range associated with the data. \\ 
     196'''Degree_Step''' \\ 
     197   type: //number// \\ 
     198   unit: //Ångström (10nm) / pixel// \\  
     199   FITS keyword: //L_STP// \\ 
     200   The spacing between spherical harmonic degrees in the data  
     201 
     202== 8. Data Source == 
     203 
     204'''Observatory''' \\  
     205      type: //menu// \\ 
     206      FITS keyword: //OBSERVTY// \\  
     207      An identifier of the observatory, space platform, or network of observatories (or spacecraft) from which the data originate. In the case of networks such as GONG or CLUSTER, the particular observatory site or spacecraft may be identified by Instrument if each member is single-instrument. In the case of multi-instrument multi-site networks, another Data Source search parameter (Site or Instance or Platform or Network) may be required. Note that network is used in the sense of functionally identical instruments deployed in different locations, and not coordinated data collections from distinct instruments, such as the H-alpha Network; that is considered a Provider.  
     208      The recognized values are those in the data registry, and the list is subject to modification whenever the data registry is modified. At the time of writing, they include the following:  
     209      * '''BBSO''' : Big Bear Solar Observatory  
     210      * '''Evans''' Solar Telescope, Sacramento Peak  
     211      * '''GONG''' : Global Oscillations Network Group 
     212      * '''JSPO''' : Jeffreys South Pole Observatory  
     213      * '''KANZ''' : Kanzelhöhe Solar Observatory  
     214      * '''KPVT''' : Kitt Peak Vacuum Tower Telescope  
     215      * '''McMath''' Solar Telescope, Kitt Peak  
     216      * '''MEDN''' : Observatoire de Paris, Meudon  
     217      * '''MLSO''' : Mauna Loa Solar Observatory  
     218      * '''MtWilson''' : Mt. Wilson 60ft Tower Telescope  
     219      * '''Nançay''' Radio Observatory  
     220      * '''OACT''' : Osservatorio Astrofisico di Catania  
     221      * '''PicMidi''' : Observatoire du Pic du Midi 
     222      * '''SOHO''' : Solar and Heliospheric Observatory  
     223      * '''SOLIS''' : Synoptic Optical Long-term Investigations of the Sun  
     224      * '''OBSPM''' : Observatoire de Paris, Meudon  
     225      * '''OVRO''' : Owens Valley Radio Observatory  
     226      * '''TON''' : Taiwan Oscillations Network  
     227      * '''YNAO''' : Yunnan Astronomical Observatory  
     228      * '''Yohkoh'''  
     229      For the current list, consult the [https://vso.nso.edu/cgi/show_details?keyword=SOURCE Registry]. \\ 
     230 
     231'''Instrument''' \\  
     232      type: //menu// \\ 
     233      FITS keyword: //INSTRUMT// \\ 
     234      For multi-instrument space observatories, an identifier of the particular instrument from which the data originate. For observatories, the Instrument may refer to a particular telescope or to one of multiple standard configurations of telescope plus detectors. For the list of instruments registered, consult the [https://vso.nso.edu/cgi/show_details?keyword=SOURCE Registry]. \\ 
     235'''Provider''' \\  
     236      type: //menu// \\  
     237      The identifier of the data archive providing search and retrieval functions for the data in question. The same data may of course be mirrored at two or more archives. Since the provider id is at least implicit in a data registry, this just means that the same data set would appear in multiple registries. Some data providers may be virtual, that is the query (but not the archive and distribution) services may be handled by other servers with access to their database information as proxies. \\ 
     238      Recognized values at the time of writing:  
     239      * '''HANET''' : H-alpha Network, Big Bear Lake  
     240      * '''HAO''' :High-Altitude Observatory, Boulder  
     241      * '''MSU''' : Montana State University, Bozeman  
     242      * '''NSO''' : National Solar Observatory, Tucson  
     243      * '''OBSPM''' : Observatoire de Paris, Meudon  
     244      * '''OVRO''' : Owens Valley Radio Observatory  
     245      * '''SDAC''' : Solar Data Analysis Center, Greenbelt  
     246      * '''SHA''' : Stanford Helioseismology Archive \\ \\ 
     247      For the current list, consult the Registry  
     248 
     249== 9. Suggestions for Additional Search Parameters == 
     250 
     251The following search parameters or categories are under consideration for possible inclusion in future versions of the VSO Data Model:  
     252* Data processing information - menu?  
     253* Data format - menu? Possible data formats may include: ASCII, FITS, JPEG, GIF, PNG, MPEG, TIFF  
     254 
     255== 10. Nicknames == 
     256 
     257Nicknames for famous combinations od Search Parameters were introduced in Version 1.7 of the Data Model in a separate table. Here they are incorporated in the defining document. Certain problems remain to be resolved. For example, mechanisms are required for designating a logical OR of menu-type parameters, and for specifying whether a Bounding_Radius is an inner radius or an outer radius. \\ \\ 
     258White-light image \\ 
     259   Observable='''intensity''', Data_Layout='''image'''  
     260   Wave_Type={'''broad''' | '''narrow'''} Wave_Minimum≥'''3000''', Wave_Maximum≤'''10000'''  
     261coronagraph image  
     262   Observable='''intensity''', Data_Layout='''image'''  
     263   |Observation_Center_West|≤'''20''', |Observation_Center_North|≤'''20''', Bounding Radius≥'''950''' (excluded)  
     264H-alpha image  
     265   Observable='''intensity''', Data_Layout='''image''' 
     266   Wave_Type='''line''', Wave_Minimum≥'''6558''', Wave_Maximum≤'''6568'''  
     267Ca-K image  
     268   Observable='''intensity''', Data_Layout='''image''' 
     269   Wave_Type='''line''', Wave_Minimum≥'''3919''', Wave_Maximum≤'''3952'''  
     270He 10830 image  
     271   Observable='''intensity''', Data_Layout='''image''' 
     272   Wave_Type='''line''', Wave_Minimum≥'''10825''', Wave_Maximum≤'''10833''' 
     273Na-D image  
     274   Observable='''intensity''', Data_Layout='''image''' 
     275   Wave_Type='''line''', Wave_Minimum≥'''5888''', Wave_Maximum≤'''5898'''  
     276Hard X-ray image 
     277   Observable='''intensity''', Data_Layout='''image'''  
     278   Wave_Minimum≥'''0.2''', Wave_Maximum≤'''10''',  
     279Soft X-ray image  
     280   Observable='''intensity''', Data_Layout='''image''' 
     281   Wave_Minimum≥'''5''', Wave_Maximum≤'''150''',  
     282EUV image  
     283   Observable='''intensity''', Data_Layout='''image''' 
     284   Wave_Minimum≥'''100''', Wave_Maximum≤'''1250''',  
     285UV image  
     286   Observable='''intensity''', Data_Layout='''image''' 
     287   Wave_Minimum≥'''900''', Wave_Maximum≤'''3800''',  
     28810.7 cm image  
     289   Observable='''intensity''', Data_Layout='''image''' 
     290   Wave_Type='''narrow''', Wave_Minimum≥'''1.06*10^9^''', Wave_Maximum≤'''1.08*10^9^''',  
     291Continuum image  
     292   Observable='''intensity''', Data_Layout='''image'''  
     293   Wave_Type='''narrow'''  
     294Full-disk magnetogram  
     295   Wave_Type='''line''', Data_Layout='''image'''  
     296   Observable={ '''LOS_magnetic field''' | '''vector_magnetic field''' }  
     297   |Observation_Center_West|≤'''20''', |Observation_Center_North|≤'''20''', Bounding Radius≥'''800'''  
     298LOS magnetogram  
     299   Observable='''LOS_magnetic field''', Data_Layout='''image'''  
     300   Wave_Type='''line''' 
     301vector magnetogram  
     302   Observable='''vector_magnetic field''', Data_Layout='''image'''    
     303   Wave_Type='''line'''  
     304Full-disk dopplergram  
     305   Observable='''LOS_velocity''', Data_Layout='''image'''  
     306Wave_Type=line  
     307   |Observation_Center_West|≤'''20''', |Observation_Center_North|≤'''20''', Bounding Radius≥'''800'''  
     308Na-D dopplergram, Data_Layout='''image'''  
     309   Observable='''LOS_velocity''', Data_Layout='''image'''  
     310   Wave_Type='''line''', Wave_Minimum≥'''5888''', Wave_Maximum≤'''5898'''  
     311Ni-6768 dopplergram  
     312   Observable='''LOS_velocity''', Data_Layout='''image'''  
     313   Wave_Type='''line''', Wave_Minimum≥'''6767''', Wave_Maximum≤'''6769''' 
     314K-7699 dopplergram  
     315   Observable='''LOS_velocity''', Data_Layout='''image''' 
     316   Wave_Type='''line''', Wave_Minimum≥'''7698''', Wave_Maximum≤'''7700'''  
     317EUV Spectrum  
     318   Observable='''intensity''', Data_Layout='''spectrum'''  
     319   Wave_Type='''broad''', Wave_Minimum≥'''100''', Wave_Maximum≤'''1250''' 
     320UV Spectrum  
     321   Observable='''intensity''', Data_Layout='''spectrum'''  
     322   Wave_Type='''broad''', Wave_Minimum≥'''900''', Wave_Maximum≤'''3800''' 
     323Visible Spectrum  
     324   Observable='''intensity''', Data_Layout='''spectrum'''  
     325   Wave_Type='''broad''', Wave_Minimum≥'''3500''', Wave_Maximum≤'''10000''' 
     326IR Spectrum  
     327   Observable='''intensity''', Data_Layout='''spectrum'''  
     328   Wave_Type='''broad''', Wave_Minimum≥'''7000''', Wave_Maximum≤'''3.5*10^6^'''  
     329Atlas Spectrum  
     330   Observable='''intensity''', Data_Layout='''spectrum'''  
     331   Wave_Type='''broad (?)'''  
     332Helioseismic Time series  
     333   Observable={ '''wave_power''' | '''wave_phase''' | '''oscillation_mode_parameters''' }  
     334Light Curve Time series  
     335   Observable='''intensity''', Data_Layout='''time_series''' 
     336 
     337 
     338 
     339 
     340 
     341