5 | | == OpenDap == |
6 | | The protocol OPeNDAP (Open-source Project for a Network Data Access Protocol). This includes standards for encapsulating structured data, annotating the data with attributes and adding semantics that describe the data. OPeNDAP is widely used by governmental agencies such as NASA and NOAA to serve satellite, weather and other observed earth science data. |
| 5 | Project-Meta is a software to help you to manage your open data, using the protocol OpenDAP. |
| 6 | The initiative is supported by the European Commission as part of the project Hydralab+ of the Horizon 2020 programme. |
| 7 | This programme requests that research data are open access, that is providing online access free of charge to the end-user and reusable. |
| 8 | Furthermore access must allow the right to copy, distribute, search, link, crawl and mine the data. |
| 9 | In addition to these general requests, we aim at achieving the following goals: |
| 10 | 1. Allow the end user to scan and visualise the data without downloading. |
| 11 | 2. Integrate the process in the data analysis procedure, with minimal additional work. |
8 | | The protocol is based on http, so that data can be scanned with an ordinary web browser. However added functionality of data visualization is provided by graphics programs (like Matlab, GrADS, Ferret or ncBrowse). Compared to ordinary file transfer protocols (e.g. FTP) a major advantage using OPeNDAP is the ability to retrieve subsets of files, so it is possible to work remotely without downloading whole data files. Although any file format can be use, data are often in HDF or NetCDF formats. The older NetCDF format is limited to arrays of numbers, while HDF provides wider possibilities of data structures (and it contains NetCDF as a particular case). We choose the NetCDF format which is sufficient for most experimental data and can be more easily read with a variety of software. |
| 13 | |
| 14 | == OPeNDAP == |
| 15 | |
| 16 | The protocol OPeNDAP (Open-source Project for a Network Data Access Protocol). |
| 17 | This includes standards for encapsulating structured data, annotating the data with attributes and adding semantics that describe the data. |
| 18 | OPeNDAP is widely used by governmental agencies such as NASA and NOAA to serve satellite, weather and other observed earth science data. |
| 19 | |
| 20 | The protocol is based on http, so that data can be scanned with an ordinary web browser. |
| 21 | However added functionality of data visualization is provided by graphics programs (like Matlab, GrADS, Ferret or ncBrowse). |
| 22 | Compared to ordinary file transfer protocols (e.g. FTP) a major advantage using OPeNDAP is the ability to retrieve subsets of files, |
| 23 | so it is possible to work remotely without downloading whole data files. |
| 24 | Although any file format can be use, data are often in HDF or NetCDF formats. |
| 25 | The older NetCDF format is limited to arrays of numbers, while HDF provides wider possibilities of data structures (and it contains NetCDF as a particular case). |
| 26 | We choose the NetCDF format which is sufficient for most experimental data and can be more easily read with a variety of software. |
| 27 | |
13 | | The first step is to make a list of the data folders to display. This list needs to be introduced in a text file, complemented by some information about the authors of the work and about related publications. This text file must be put in your current folder with the name `PROJECT-META.yml`. The text structure must follow some simple rules consisting in the YAML format. An example could be found in the Project-Meta repository or online [http://servforge.legi.grenoble-inp.fr/pub/soft-trokata/project-meta/PROJECT-META.sample.yml PROJECT-META.sample.yml]. |
| 31 | The creation of the OpenDAP repository is done by the script |
| 32 | [http://servforge.legi.grenoble-inp.fr/pub/soft-trokata/project-meta/project-meta.html project-meta] |
| 33 | using UNIX commands, scripts in Perl and C++. |
| 34 | |
| 35 | The first step is to make a list of the data folders to display. |
| 36 | This list needs to be introduced in a text file, complemented by some information about the authors of the work and about related publications. |
| 37 | This text file must be put in your current folder with the name `PROJECT-META.yml`. |
| 38 | The text structure must follow some simple rules consisting in the YAML format. |
| 39 | An example could be found in the Project-Meta repository or online |
| 40 | [http://servforge.legi.grenoble-inp.fr/pub/soft-trokata/project-meta/PROJECT-META.sample.yml PROJECT-META.sample.yml]. |
| 41 | |