The core partner data centres that are integrated in NorDataNet are listed in https://www.nordatanet.no/en/node/69. In addition to this NorDataNet harvests information on relevant datasets from a number of other data centres. The data centre responsible for the data presented is usually (but not always) listed in the discovery metadata. In essence NorDataNet is an aggregating service that combines information from a number of existing data centres.
Citation of data and service
If you use data retrieved through this portal, please acknowledge our funding source:
Research Council of Norway, project number 245967/F50, Norwegian Scientific Data Network.
Always remember to cite data when used!
Citation information for individual datasets is often provided in the metadata. However, not all datasets have this information embedded in the discovery metadata. On a general basis a citation of a dataset include the same components as any other citation:
author, title,
year of publication,
publisher (for data this is often the archive where it is housed),
edition or version,
access information (a URL or persistent identifier, e.g. DOI if provided)
All partner repositories of NorDataNet support Digital Object Identifiers (DOI), but not all datasets are minted. Whether or not minted depends often on source of the data (e.g. operational data are often yet not minted). However, all data centres support persistent identifiers according to local systems. The information required to properly cite a dataset is normally provided in the discovery metadata the datasets.
Brief user guide
The Data Access Portal has information in 3 columns. An outline of the content in these columns is provided above. When first entering the search interface, all potential datasets are listed. Datasets are indicated in the map and results tabulation elements which are located in the middle column. The order of results can be modified using the "Sort by" option in the left column. On top of this column is normally relevant guidance information to user presented as collapsible elements.
If the user want to refine the search, this can be done by constraining the bounding box search. This is done in the map - the listing of datasets is automatically updated. Date constraints can be added in the left column. For these to take effect, the user has to push the button marked search. In the left column it is also possible to specific text elements to search for in the datasets. Again pushing the button marked "Search" is necessary for these to take action. Complex search patterns can be constructed using logical operators identified in the drop down menu with and phrases embedded in quotation marks. Prefixing a phrase with '-' negates the phrase (i.e. should not occur in the results). Searches are case insensitive.
Other elements indicated in the left and right columns are facet searches, i.e. these are keywords that are found in the datasets and all datasets that contain these specific keywords in the appropriate metadata elements are listed together. Further refinement can be done using full text, date or bounding box constraints. Individuals, organisations and data centres involved in generating or curating the datasets are listed in the facets in the right column. The combination of search fields (including facets) is based on a logical "AND" combination of the fields, i.e. all conditions are fulfilled for the results provided.
The dataset contains ship radar images with 1 min interval. Images cover the area of 15 * 15 km with nominal resolution of 12.5 m. The bow of the ship is always pointing to left. The images have been recorded with an independent radar server, developed by Image Soft Ltd. On the server, images have been pre-processed by temporal median filtering of 15-20 s. The image capturing is described in detail in Karvonen, 2016.
Karvonen, J. (2016): Virtual radar ice buoys – a method for measuring fine-scale sea ice drift (https://doi.org/10.5194/tc-10-29-2016), The Cryosphere, 10, 29–42.
The dataset presents the list with essential details on the Synthetic aperture radar (SAR) images acquired during the series of Nansen Legacy cruises. The cruises were conducted during 2018-2022 with the Norwegian ice-going research vessel Kronprins Haakon (KPH) to the northern Barents Sea, area north of Svalbard and further into the central Arctic, namely Nansen and Amundsen basins.
For more details on the Nansen Legacy project (Norwegian: “Arven etter Nansen”), research goals, sampling strategy and the associated activities please follow the link https://arvenetternansen.com/.
The acquired scenes comprise primarily of Radarsat-2 (RS-2) imagery. Some images were also acquired by TerraSAR-X (TSX). The scenes were ordered for various sea ice research and focus on areas that were sea-ice covered at the times of the cruises. The timings of the ordered acquisitions were set to overlap with the actual planned sea ice station or/and helicopter borne EM ice thickness surveys. However, due to a minimal time lapse of 3 days (RS-2) or 24 hours (TSX) between the ordering deadline and the actual acquisition, the drift of sea ice as well as adjustments in cruise plans, it was often not possible to ensure an overlap between the scene and the actual activity in the scene bounding box. When the onsite activity such as the ice station or EM-survey did fall into the bounding box of the acquired scene, this event was noted in the “Comment” field of the presented dataset.
One should note that the images were acquired for different applications and hence feature different major settings such as incidence angles, mode and polarization, etc. These are also indicated in the presented dataset. For the use of actual images or products derived from the images (e.g. classified scenes), interested users are advised to contact the respective points of contact for the dataset at NPI and UiT.
The list of SAR scenes is available as Excel and csv files.