The aim of the project KCDC (KASCADE Cosmic Ray Data Centre) is the installation and establishment of a public data centre for high-energy astroparticle physics based on the data of the KASCADE experiment.

KCDC is the ’KASCADE Cosmic Ray Data Centre’, where via a web-based interface data of an astroparticle physics experiment is made available to anyone.

The KASCADE experiment, financed by public money, was a large-area detector for the measurement of high-energy cosmic rays. These charged particles (fully ionized atomic nuclei) are accelerated in active cosmic objects, propagated through the intergalactic and interstellar medium of the Universe, and reach our Earth with a rate of less than one per minute and square meter. Hitting our Atmosphere, they subsequently interact with nuclei and generate a cascade of millions of secondary particles which partly reach the Earth's surface and can be detected. This phenomenon is called an extensive air-shower, EAS. With an array of particle detectors this secondary cosmic radiation in individual EAS can be detected and the parameters of the impinging primary particle reconstructed. The energy spectrum, elemental composition and the arrival distribution of the primary cosmic rays are investigated and through this the astrophysical question to the origin of cosmic rays is studied. KASCADE was extended to KASCADE-Grande in 2003 to reach higher energies of primary cosmic rays where the rate decreases to less than one per day and square meter. KASCADE-Grande finally stopped the active data acquisition of all its components at the end of 2012 and is presently being decommissioned. The international collaboration of the experiment, however, continues the detailed analysis of nearly 20 years of data.

Moreover, with KCDC provide the general public with the edited data, i.e. the reconstructed parameters of the primary cosmic rays measured via the detection of EAS with the KASCADE-Grande experiment. The aim of this particular project is the installation and establishment of a public data centre for high-energy astroparticle physics. In the research field of astroparticle physics, such a data release is a novelty, whereas in astronomy the data publication has been established for a long time. But, due to basic differences in the measurements of cosmic-ray induced air showers compared with astronomical data, KCDC provides the first conceptional design as to how the data can be treated and processed so that they are reasonably usable outside the community of experts in the research field. The first goal of KCDC is to make the data from the KASCADE experiment available to the community.

The procedure to prepare and publish the huge amount of data must be developed with respect to consistent calibration, filtering and formatting in a portable format. In addition, access rights or license play a role. We publish all important parameters of the reconstructed data, which are necessary to do physics analysis in the field of cosmic radiation.

In accordance with the ‘Berlin Declaration on Open Data and Open Access’ the KASCADE Collaboration and KIT decided to provide free access to the KASCADE data via the internet. To fullfill all requirements associated with such an endeavour, KCDC was created as a state of the art webportal facilitating easy access to data under a free licence. But KCDC is even more than just another website with scientific data. On the webportal we provide information on the experiment, the data and the physics to an interested audience of both scientists and non-scientist.
Our reasons to choose this approach were:

• high flexibility through the easy access via web browsers and online forms
• online selection and limitation of data by the user
• release of the developed software framework for other experiments in the future

The β-Version of the KCDC web portal is an officially released version of the product which includes most of the aspired functionality. The β-version is, even as far progressed as it is, still in a stage of testing in order to furthermore improve the webportal together with our users. Therefore, we highly value any input from our users.
We are continually working to improve KCDC for all our users and aim towards creating not only a high usability webportal but also to provide all the necessary information for understanding and working with the data.

The webportal was developed with compatibility towards most of the present day web browsers. This especially includes Chrome, Firefox, Internet Explorer and Safari. The supported versions are listed as follows:

• IE version IE7 and above
• Firefox version FF22 and above
• Chrome version 26 and above
• Safari version S5 and above

KCDC is not compatible with mobile devices at the moment.

After the official release in November 2013, patches will be provided on a patchday possibly causing short downtimes of some hours. Patchdays will be announced both on twitter and the webportal itself. Security or critical bug fixes will be provided as the need arises and also outside regular patchdays.
In the section 'Changelogs', information on recent changes introduced during patchdays will be listed.

If you want to get in touch with the KCDC development team you can always send us an email using the links provided on our homepage.
If you want to report a bug, please use the ‘Bug Report’ button on the “KCDC Homepage”. If you want to send us a screen shot with the bug report you should do this by mail via the above mentioned mail address.
For bug reports we are especially interested in:

• which browser was used?
• which version number does your browser have?
• on what platform did you run the browser (WINDOWS, LINUX, MAC)?
• what is the troubling url? (automatically provided if you use the 'Bug Report' button)
• and of course a detailed (if possible) description of the problem

Information will be provided either in orange coloured information boxes nearly everywhere on the web portals right hand side. More detailed information will be available from the KCDC-Manuals which can be accessed via th menu item 'Materials'.
On the ‘Announcements’ page you will find regular updated information on new releases and changes to the KCDC portal.