Heterogeneous Missions Accessibility Follow-On Online Data Access (HMA-FO ODA)

HMA-FO ODA Use Cases & Scenarios Feedbacks from ESA internal meeting on ODA – ODA in general – FTP used only for subscription – Use of enhanced Online Data Access, i.e via HTTP URL – client is EOLI based – Issues from GSCDA and licensing issues – no on-the-fly processing – data downloaded as they are – Issues from User Services Next Generation – user can download products pre-cut according to World Reference System – products are created/cut according to WRS – no cutting and no processing allowed – It is required to download – selected bands (subsetting) – bulk data – data in original format

HMA-FO ODA Use Cases & Scenarios Feedbacks from ESA internal meeting on ODA – Even scientists are very happy with standard frames delivery – It is important to get data via simple (or single) query in case of requests like ("Get (MERIS?) coverage of Spain"), i.e 5000 queries are not acceptable – No support for geo-cutting and sub-setting, the user will accept the product as is, as pre-cut from the mission’s standard frames tiling operation

HMA-FO ODA Use Cases & Scenarios Virtual WCS – Work with original data (e.g. rolling archive) without pre-building a coverage – Create coverages – Allow subsetting – On-the-fly processing (?) – Work with native Coordinate Reference System – How to make WMS previews/quicklook of multi-product coverages

HMA-FO ODA Use Cases & Scenarios – Type of query/requests – Get full dataset/coverage – Get part of a dataset (e.g. AOI) – Subsetting (e.g. get one or more bands of a multiband dataset/product) – Get (part of/subsets of) datasets in a time window or at intervals – Get bulk data (e.g. MERIS Coverage of Spain) – Service Requirements – Get data in the original format – Minimise the amount of downloaded data – Use a single query for bulk download – Get data per predefined CRS (e.g. World Reference System) – Base products cut along WRS

Coverage access services high level requirements (goals) – Goal 1: Inter/Intra-Community Interoperability – Goal 2: Support a variety of Coverage Domains – Goal 3: Support a variety of Coverage co-domain values – Goal 4: Support Coverage semantics – Goal 5: Service basic functionalities – download, subsetting, metadata interoperability – Goal 6: Service advanced functionalities – Advanced metadata interoperability, Reprojection/Resampling – Goal 7: Service implementability and sustainability – Goal 8: Service efficiency – Goal 9: Service reliability and stability – Goal 10: Service scalability and extensibility – Goal 11: Reuse Existing capacity – Goal 12: Software environments interoperability From “Enabling interoperability for Earth Science coverage access services” by B.Domenico & S.Nativi

HMA-FO ODA Use Cases & Scenarios – HMA-FO_ODA-RB-SSS_EOX 1.2 – Requirement Baseline - Software System Specification – Contains – A set of ODA use cases and scenarios – ODA Requirements derived from use cases/scenarios – ODA use cases and scenarios are classified as – Visualize data (View Service) – Access data (Download Service) – Supply data (Add or Update / Transactional Service) – Other specialized Use Cases

Use Case 7: EO WMS and EO WCS Scenario 1 – US7_1: EO WMS Viewing and EO WCS Download following EO Dataset discovery – a human user accesses an EO Product Catalogue Client, makes a “query” and is presented with a list of metadata records that match his query criteria – optionally the user can ask for more information on an individual product using a “present” operation – either from the “Search Result” form or the “Present Result” form, the user can choose to overlay the browse image on top of the map of the Catalogue Client – the user downloads the coverage

Use Case 7: EO WMS and EO WCS Scenario 1 – US7_1: EO WMS Viewing and EO WCS Download following EO Dataset discovery – Actors and interfaces – Human user – EO EP of ebRIM CSW Service instance (EO Product Catalog) – EO EP of ebRIM CSW and EOP WMS Client Application (e.g. SSE/HMA Portal) – WMS EO Application Profile Service instance – WCS EO Extension Service instance – Initial Status and Preconditions – User has discovered the EO Product Catalogue Client Application (either directly or via the Collection/Service Discovery service) and has optionally logged onto the client application

Use Case 7: EO WMS and EO WCS Scenario 1 – US7_1: EO WMS Viewing and EO WCS Download following EO Dataset discovery – Type of query – Get full dataset/coverage – Get part of a dataset (e.g. AOI) – Subsetting (e.g. get one or more bands of a multiband product) – Get (part of/subsets of) datasets in a time window or at intervals – Get bulk data (e.g. MERIS Coverage of Spain) – Service Requirements – Get data in the original format – Minimise the amount of downloaded data – Use a single query for bulk download – Get data per predefined CRS (e.g. World Reference System) – Base products cut along WRS

Use Case 7: EO WMS and EO WCS Scenario 1 – US7_1: EO WMS Viewing and EO WCS Download following EO Dataset discovery – Evolution – the user submits his query (e.g. collection, AOI, time period, subsetting, bulk data) via the client application to the EO Product catalog Service (EO EP ebRIM CSW GetRecords) – EO Product catalog replies with metadata for the (first) set of records and the client application shows the metadata in a list view where one of the elements that is presented is a thumbnail image delivered via the EO Profile of WMS service – user opts to visualise more extended metadata – the catalog client sends a Present request (EO EP ebRIM CSW GetRecordById) and displays the information to the user – a browse image (Quicklook) delivered via an EO Profile of WMS instance is shown – the user can opt to overlay the browse image on top of the map of the catalog Client – the user can navigate on the map of the catalog Client and inspect in detail the EO Product – the user can download the product with the options on CRS, spatial extent, output format resolution and or bands using the WCS

Use Case 7: EO WMS and EO WCS Scenario 1 – US7_1: EO WMS Viewing and EO WCS Download following EO Dataset discovery – Final status and post conditions – User has discovered EO Products and has evaluated their usability for his specific purpose by visualising interactive browse images (optionally in different band combinations) with their associated information like bitmasks and derived products – Subsequently the user has downloaded the product

Use Case 7: EO WMS and EO WCS Scenario 1 – US7_1: EO WMS Viewing and EO WCS Download following EO Dataset discovery – Variations: When the EO Profile of WMS offers for each EO Product – nested WMS layers representing “spatial metadata bitmasks” (e.g. cloud, snow, land, sea, … masks), – the Catalogue client could give the user the possibility to visualise the individual mask layers on top of the map of the Catalogue Client – nested WMS layers representing “spatial metadata bitmasks” (e.g. cloud, snow, land, sea, … masks), “GeoPhysical parameter coverage datasets” (e.g. chlorophyll) or band coverage datasets, – the user can – add a map context as a set of map layers to the Catalogue Client map – use the Map Client Layer Management controls to – show/hide the individual layers – change the style for the mask layers – select the appropriate Dimension values for the band datasets

HMA-FO ODA Use Cases & Scenarios Additional Use Cases

Use Case 2: Access / Retrieve Data Scenario 2 – US2_2: Use WCS – Basic scenario: get coverage via WCS – Multiple cases of requests/downloads – complete/single scene – subset of a scene/mosaic – time series of a dataset (start/end time, period) – data within a time slot (start/end time) – layers of a coverage – access multi-dimensional datasets and extract information for multiple ranges and for a time-slot or time-series – Can be used as an extended view service

Use Case 2: Access / Retrieve Data Variations: Security – A service provider wants to restrict access to authenticated users at different levels e.g. – at Service level, – at Dataset level, – for a certain AOI, – for a certain timeframe, etc. – This requires that – the provided service can manage such restrictions (policies) – information regarding the user's identity (e.g. user name/password or security token) is passed within the Service Request

Use Case 2: Access / Retrieve Data Subscription (and FTP) – The user registers and makes a subscription request to the data provider – Whenever a new product (data) is available the data provider sends a notification message to the subscribers with info for FTP download – The subscribers access the FTP site with the info (username, password) received in the notification message and download the data via FTP pull – Alternative solution, the data provider not only sends a notification, but pushes the data to a FTP server on the user's side once it is available

Use Case 2: Access / Retrieve Data Scenario 3 – US2_3: Retrieve data in Service Chain – A user wants to – get EO data of a AOI, requiring multiple scenes to cover it, – merge them into a mosaic, – having the mosaic reprojected, – using these settings to retrieve a time-series of a predefined timeslot – pick up these datasets from a FTP server – In this workflow a WCS (for the AOI and the TOI), a WCPS (for the mosaicing), a WCTS or WPS (for the reprojection) and FTP server (delivery) would need to be combined

Use Case 2: Access / Retrieve Data

Use Case 3: Optimizing Access Scenario 2 – US3_2: Data is Available from Different Servers – Two cases for a faster access – the same file is replicated and provided by multiple sources/providers – a large dataset is split and provided by multiple sources/providers

Use Case 5: Supply Data Scenario 3 – US5_3: Update a part of a Coverage (Mosaic) keeping track of its history – Includes the knowledge which areas of the mosaic originate from which input – The history changes as new data is ingested, extending the area covered by the mosaic and/or overwriting parts of it – Another extension is to provide access to previous versions of a mosaic as a time series of coverages

Use Case 5: Supply Data Variations: Simpler cases – Add a new coverage – Update a coverage – Delete a coverage

Use Case 6: Client Use Cases Scenario 1 – US6_1: Visualize and Download Coverages – Evolution – The user is presented with the WebMapViewer from a Portal Service – in the WebMapViewer, the WCS coverages will be listed – the user visualizes the coverage metadata via the DescribeCoverage – the user accesses a Coverage layer and applies changes to the coverage that are shown on the map – the user chooses to download the coverage (or a part of it) – Result – The user has tuned the WCS coverage appearance to his liking and/or has evaluated the coverage metadata and was able to download it

Use Case 1: Visualize / Browse Data Scenario 1 - US1_1: Use WMS or WMTS – covered by the OGC Web Map Service (WMS) extended by the WMS Application Profile for EO Products – for the WMTS there is no Application Profile for EO Products available. – Service: WMS, WMTS

Use Case : EO WMS and Discovery Scenario: Discovery and View using EOP WMS – A human user accesses an EOP WMS Client, specifies the product collections that he wants to search and specifies a time period – As a result a map layer is shown that gives the outline (Bounding Box) for all the matching images – The user can select an image outline and retrieve the EO Product metadata or can opt to visualise the default image or any of the nested mask, derived data or “different band combinations” data layers for the selected product

Use Case : EO WMS and Discovery Scenario: Discovery and View using EOP WMS – Actors and interfaces – Human user – EOP WMS Client Application (e.g. SSE Portal) – WMS EO Application Profile Service instance – Optionally EO EP of ebRIM CSW Service instance (EO Product Catalog) – Initial Status and Preconditions – Service provider has configured the EOP WMS Client to point to a particular EOP WMS and optionally EO EP CSW instance – User has discovered the EOP WMS Client Application (either directly or via the Service Discovery service – see variation) and has optionally logged onto the Client application

Use Case : EO WMS and Discovery Scenario: Discovery and View using EOP WMS – Evolution – the user calls a search specifying AOI (from a map), collection and time period – the map client sends a GetMap request to the EOP WMS Service to retrieve a map of the outline layer for the corresponding product collection and for the time interval that was specified – the EOP WMS Service returns a map that shows the outline layer – user selects the “Identify” tool, and subsequently clicks on an outline on the map – the map client then issues a “WMS GetFeatureInfo” Request to the EOP WMS Service instance – the EOP WMS Service returns metadata about the EO Product(s) located within the selected area that was clicked; the metadata that is returned shall be encoded in XML and should “ideally be encoded” as EO GML – specific EOP WMS Clients present this EO GML in HTML format and extract the begin time/end time (and productIdentifier) from this EOP GML metadata – the map client can then use this time to formulate GetMap requests to retrieve the “default browse image” for only the identified product – using the “Layer manager” in the map client, the user can select the nested layers to show, with style and band mapping (for multiple band products)

Use Case : EO WMS and Discovery Scenario: Discovery and View using EOP WMS – Final status and post conditions – User has discovered EO Products and has evaluated their usability for his specific purpose by visualising interactive browse images with their associated information like bitmasks and derived products – Variations – Instead of starting from the EOP WMS Client, this use case could start from the Service/collection discovery client where the user searches on the collection of interest, then discovers the EOP WMS service that operates on this collection – After selecting the EOP WMS Service, the portal client application could forward to the corresponding EOP WMS client application