Intern:Binary object

Binary objects (BO or binary large object = BLOB) are digital files consisting of plain text, photos, grafics, films, sound or binary data in specific formats. BO are stored in a file system on a hard disc/tape robot combination (hs=hirachical storage). The metadata are stored in Pangaea with a link to the BO.

BLOBs are archived in three steps:

(A) Upload of BO and comment files
 * 1) Upload the files to the storage system of your choice. It is important, that the path to the data is well defined and remains stable on a long-term scale. BOs should be archived in at least one standard exchange format (jpg, gif, tiff, png, pdf, txt, shape, wave, ...). Proprietary formats should follow international standards if available (sgy, NetCDF). when uploading images, the files may contain a description also in the IPTC metadata fields. This ensures, that the image is always accompanied by its descriptive information.
 * 2) Upload comment files.
 * 3) Keep path in mind.

(B) Metadata definition or import
 * 1) If locations of the BO are related to a campaign (cruise/expedition), information about its name (code/label), time, basis/ship, responsible scientist, and citation of a report may be given.
 * 2) If a BO is georeferenced, provide a list of events (station/site/profile), describing the location of each BO. Mandatory are the fields LabelEvent (must be unique), LatitudeEvent, LongitudeEvent; recommended are ElevationEvent, DateEvent, TimeEvent, Gear; (for profiles, all fields can be given twice for start and end point); optional fields are Remarks and OptionalLabel.
 * 3) If a BO is not georeferenced, no campaign or event need to be defined.
 * 4) Ensure that authors are defined in the staff table and references are added to the reference table.

(C) Data import Data are archived with one data description per event. Required description fields are: Data set title, principle investigator (PI), method, comment, and reference(s) if published. A detailed description of the BO can be added as a pdf- or txt-file.

There are different ways of archiving BOs:

a) The event is a station with one (two) pair of latitude/longitude -> all BOs are added to this single event, but may be differentiated by geocode DATE/TIME.

b) The event is a profile described in detail by several pairs of lat/long, giving each BO its own georeference; -> in this case a list must be imported, containing the columns:
 * Event label
 * date/time
 * latitude
 * longitude (both in decimal degree)
 * path to the BOs as URL
 * further columns with analytical and/or technical data may be added as required.

c) If a BO is not georeferenced, the data description is defined in the following steps:
 * 1) open the Data sets table, click on New
 * 2) add Author(s), Title, Source or Reference and Project on the Basics card
 * 3) add Comment, Keywords and Topologic type on the Details card
 * 4) on the Web card, check the static box (which means, that you will add a static link)
 * 5) add the path linking the BO in the URL field
 * 6) add the path to a comment file in the URL Data details field
 * 7) leave the field Export filename empty
 * 8) press Save

If tables containing links to BOs are imported as data files, filenames should follow a certain syntax: EventLabel_describer.extension. The describer can be used individually and may contain a code (date/time, ordinal number, depth, length, ...) or the type of a BO (photo, x-ray, description, video, ...) or a combination of both.

Examples for filenames of BOs:
 * Photo EventLabel_photo.jpg
 * Photo of a segment EventLabel_begin-end_photo.jpg (GeoB1234-5_678-778_photo.jpg)
 * Photo, x-ray EventLabel_x-ray.tiff (GIK12345-6_000-100_x-ray.jpg)
 * Photo w time EventLabel_hh_mm_ss.png
 * Photo w date/time EventLabel_yyyy-mm-ddThh_mm_ss.jpg
 * Photo w ordinal number EventLabel_0034.png
 * Grafic of a segment EventLabel_begin-end.gif
 * Description as pdf EventLabel_begin-end_descr.pdf (GeoB1234-5_678-778_descr.pdf)
 * Plain text EventLabel_comment.txt (PS58/012-5_agecontrol.txt)
 * Film/sound sequence EventLabel_begin-end_video.avi

In case several events occured at one site (e.g. box corer followed by a piston corer), one directory, named after the site, should contain the documentation BOs of all events. This will allow a synoptic overview of the availability of all photos and graphics from the same site; however a data set description must be defined for each event (in this case all pointing to the same folder).

File types/MIME types of BO
images documents audio/video seismic archiv see also MIME Media Types
 * -.tif or tiff
 * -.jpg
 * -.png
 * -.gif
 * -.pict (should be removed)
 * -.pdf
 * -.txt
 * -.xml
 * -.ogg
 * -.wav
 * -.sgy or -.segy
 * -.zip
 * -.tar

Login/Authorization for BOs
As BOs are not stored inside the PANGAEA database, it is not possible to restrict access through the native database functions. Because of that, the files inside http://hs.pangaea.de and http://store.pangaea.de are linked to the dataset ID and the web server enforces the authorization against the dataset PIs / explicitely defined users (see Login).

It is recommeneded to link all directorys in HS/STORE to the corresponding data set (even if no authorization is required)!

To link a directory on HS/STORE to a dataset, just place an empty file with the following name in the directory: " ", where  is the ID of the data set. This file works like a "marker". It tells the web server to use this dataset ID for enforcing access constraints for all files and sub-directorys where the  files resides (do not forget the leading dot in the file name, which means "hidden" on UNIX).

Important: The restriction only works for the whole directory and all its sub-directories, so you should put every dataset in a separate directory!

If you want to enable directory listing, you can even place a " " file inside the directory, which tells the web server, to supply a listing (for all files and sub-folders).

Please note: " " files were disabled on HS/STORE. If such a file exists, the web server responds with HTTP 500 Internal Server Error.

Using this mechanism, it is also possible to restrict access to metadata/other versions of the data set (e.g. a PDF file). Just place these files in a folder on HS/STORE and place a " " file in the directory. The files can only be downloaded, if the user is logged in according to dataset's restrictions.

Examples of data sets linked to BO

 * dataset consists of graphics and photos as a documentation of a geological sediment core. In the header the fields of the metainformation as described above are listed. In HTML-view the grafic objects are shown as thumbnails, a click on a thumbnail starts download of the file in full resolution.
 * shows photos from the ocean floor along a transect. Due to a missing relation between photo and precise position, all photos are related to a single pair of latitude/longitude only; in addition the lat/longs describing the track are given in one minute time resolution as additional text file. For a convenient download of all photos an extra link is added.
 * is a fully georeferenced data set containg the description of a cruise track with links to BO as seismic and grafic files from certain segments of the track. Columns with further technical data are added. The URL shows the path to the mass storage system for BO used by PANGAEA.