Astronomers can search the WSRT archive online (temporarily unavailable, please use SDC-Helpdesk) for WSRT data that have been taken since mid-2000. Data that are in the public domain can be requested by creating a ticket through the SDC-Helpdesk identifying the corresponding project name(s) and the sequence numbers of the requested data sets.
Archive data can be provided upon request opeining a ticket via the SDC-Helpdesk. The email should contain the related project reference code and the sequence numbers of the requested data sets, as well as a specification of the requested data format (MeasurementSet or FITS). The necessary information is available from the WSRT ArchiveBrowser (see description below).
The WSRT science support will check the availability of the data: archive data are generally public one year after the last observation of a project has been made, but exceptions may be active. If the data are in the public domain, they will be uploaded on the ASTRON ftp server and the archive user will be notified on how to download them. For observations that are not older than slightly more than a year, it is not very likely that the corresponding data sets are publicly available already.
No guarantee is given of the completeness and reliability of the received data.
Data until 6 December 2002 (solved): Wrong epoch in the data headers and tables. The issue is solved and should not turn up again. However, the astrometrical accurary of data taken until 6 December 2002 should be checked against a reference catalogue (e.g. NVSS).
The WSRT ArchiveBrowser can be used to search the WSRT archive and to obtain the information necessary for a request. A detailed description can be found here or by clicking on the "?" buttons on the ArchiveBrowser form.
In a first step, the archive user will search the archive for appropriate observations of their sources, mostly making use of the possibility to specify a position and a search area in the ArchiveBrowser form or by providing a list as an ASCII file (batch mode). If the search is successful, the ArchiveBrowser returns a list of observations together with a description of the measurements in a separate window of the browser.
For an archive request, the user requires the project code(s) and the sequence number(s) of the measurements. The sequence number of a single measurement is listed on the top right of each entry (Seqnr. : XXXXXXXX) in the list returned by the ArchiveBrowser. The project code is a combination of two identifiers, the semester, and the project number, separated by a slash character ("/"). It is always identical to the first two character sequences separated by a slash character ("/") in the "ObjectName" code listed for every observation in the return list of the ArchiveBrowser: "ObjectName : XXXX/YYY/Object" corresponds to the project code XXXX/YYY.
After a list of sequence numbers of appropriate target observations has been identified, the archive user will probably also need to locate calibrator measurements accompanying the target observations. This can be achieved by resetting the ArchiveBrowser form (click on button "reset form" at the bottom of the form) to then enter the project code(s) under "Project ID" (format: XXXX/YYY, without leading or trailing whitespaces, with XXXX/YYY derived from the ObjectName as described above). The ArchiveBrowser will then return a list of all measurements in the specified project including calibrator measurements. In most (but not all) cases, it is standard to observe two primary calibrators per target observation with the WSRT, one immediately before the target observation, one immediately after the target observation. Hence, the sequence numbers of calibrator observations belonging to a certain target should not differ by a large number from the sequence number of the target observation. In doubt, the more detailed description (including observing times) of the observation(s), which can be accessed by clicking on the "more >>" button in the list returned by the ArchiveBrowser should clearly identify the appropriate calibrator measurements (and their sequence numbers).
In summary, an archive search consists of the following steps:
Two types of requests directed to the SDC-Helpdesk can be answered in a relatively short time:
A properly configured request of type 2 will be answered by sending the requesting astronomer a download link to download the archive data, or, if proprietory material has been requested, a notification that the data cannot be made available.
|Example 1: Dear WSRT support team, I would like to inquire if the following WSRT archive data sets still have proprietary status or if they are publicly available: Project code: R08A/005 Seq.-Nr.: 10804874 Seq.-Nr.: 10800504 Project code: R08A/004 Seq.-Nr.: 10800295 Seq.-Nr.: 10800459 Regards, Ms Right|
|Example 2: Dear WSRT support team, I would like to inquire if the following WSRT objects have been observed with the WSRT (there are some rumours) and if they still have proprietary status or if they are publicly available: NGC 1234 IC 5678 Best wishes, Mr Wrong|
|Example 3: Dear WSRT support team, I would like to inquire if you can make the following WSRT archive data sets available to me (uvFITS format): Project code: R08A/005 Seq.-Nrs.: 10804873 10804874 10804875 10800503 10800504 10800505 Project code: R08A/004 Seq.-Nrs.: 10800294 10800295 10800296 10800458 10800459 10800460 Regards, Mr Right|
|Example 4: Dear WSRT support team, I want to know if the following WSRT objects have been observed with the WSRT. If yes, please make the data available to me: NGC 1234 IC 5678 Best wishes, Ms Wrong|