Taking into account the Government of Luxembourg's policy to reform the civil services and to promote an easier access of State's Services especially through the internet, the National Cadastre and Topography Administration (ACT) contributes to the national eLuxembourg program and offers a new internet service to the public services as well as to the citizen in general.
With the National Geoportal of Luxembourg, ACT has created a powerful tool to communicate with the users. This tool is designed to provide the cadastral and topographic information and data which are under the responsibility of ACT, as well as geodata from other providers cooperating with the system.
The main targets of the geoportal are:
This document is targeted at the general public using the geoportal, i.e. all the non identified users who access the geoportal to view maps and product informations. The according functions are explained in the following chapters.
Please consider the following when using the geoportal:
The following picture illustrates the overall architecture of the geoportal, with the general user entering via a standard internet browser.
The system consists of different parts, whereof the Portal is the central element.
For all types of users, the Portal is the access point for the different functions.
They can use the mapping tool to vizualize maps and other geodata or get general information or details about the different products that can be ordered via the system. If they have an own user account they can send orders.
Next to the Portal is the section of the “geodata and product providers” of the geoportal. They handle the incoming orders and provide the data and information in the portal. The Portal has a series of specialized functions for these purposes.
The geoportal home page actually looks like this:
The general public user can always access the information section and use the functions in the sections “Maps and Products” and “Ask a question”.
All the functions of the mapping tool are explained in this manual.
The button “Our Products” opens the catalogue of the products available in the geoportal. This is a catalogue containing all the existing products offered by the different providers. The information sets about the products contained in the catalogue are called “metadata sets”.
In the section “Ask a question”, the menu “FAQ” ( Frequently Asked Questions) contains a list of questions + answers that may be of interest for many users. Any one can read the questions and answers.
With the button “Ask a question”, the user can formulate questions himself, which will be answered by the geoportal support team.
An authenticated user (login, password) can access to other functions that are adapted following his personal rights and permissions in the system.
In every case, he can use functions to
In this case, he has the status “customer” in the geoportal.
If he has other further going rights in the system, like
he becomes “special customer” of the geoportal.
If the user is a geodata and product provider of the geoportal, he has access to the special functions reserved for the providers:
As a geodata and product provider, the user is enabled to :
| Note : The contents of this manual can in no case imply obligations of service delivery or guarantee from ACT or other geoportal providers! |
In this chapter the general way to use the geoportal's functions is described.
All the pages are composed of:
The navigation principles are the same on every site page.
On the 1st and 2nd level, the navigation is organized in the vertical navigation bar on the left side, with mouse-over effect and highlighting of the active link by means of color change from blue to orange.
From the 3rd level downwards, navigation is incorporated in the page contents.
Every page has an arrow button on the upper right, which leads to the superior level.
The pages generally display a frame with a title composed of:
On the 1st navigation level, the pages contain a brief presentation of all the 2nd level functions.
On the 2nd navigation level, the pages contain the specific information for the actual function.
By clicking on the link mentioned above, the user can go back to the top of the page.
At the bottom of every page, on the right, the following information is displayed:
The geoportal is multilingual : Luxembourgish, French, German and English are supported. To change the language, click on the corresponding button on the upper left of the page:
All the lists with search results are paginated and contain the information split into different pages. The properties of the list contents are displayed:
All the lists can be sorted by any of its columns, either in ascending or descending way.
After being sorted, the list is reinitialized and the first list page is displayed.
To clearly present the contents, tags are frequently used.
Every tag header reacts to clicking. When a new tag is opened, the fields in the actual tag are automatically validated before switching to the new tag.
The different actions that can be done at a certain stage are represented by hypertext links, whose clickable text explains the action.
The different options are simply separated by the character .
Except for the very specific actions, the current actions will generally use the following terms:
The text is completed by an indication of the entity on which the function operates. For example “Back to the order list”.
A simple colour code is used in the interface, to specify the current state:
Note : For tags without any content, the text remains blue and italic, and will not be reactive to clicking.
For complicated procedures with an important number of intermediary actions, the user is guided through different steps like shown in the example.
The steps already passed and validated are indicated in normal font, the current step in bold font, and the next steps in italic font.
At every moment, the user can go back one ore more steps by simply clicking on the link of the corresponding step.
The geoportal exchanges information with its user. This can be data or information concerning the user's actions.
When an action of the user does not give any visible result on the screen, the system shows a message to indicate that the action has been done with success. For examble, after sending an order, the system shows the following confirmation message:
In case of an error, when entering data, the system alerts the user that some rules have not been respected and specifies the problem that has to be corrected.
In the geoportal exist several user levels. Every user has a user account associated to a set of profiles. In the profiles the individual rights concerning the mapper, the catalogue the webservices and the overall geoportal functions are saved.
The following chapter explains the principles that rule the geoportal and that make sure that the access restrictions can be adapted very finely to the user’s needs.
The actors in the geoportal can be split into 4 groups:
When opening the geoportal's home page, the user automatically acts as a “general public” user, as long as he has not logged in the system by providing his user account name and his password. The “general public” is the anonymous standard user, who is granted with the minimal user rights in the system and who can do the basic operations in the geoportal. He can learn about the existing and available products by viewing the metadata catalogue's contents, and view the geodata in the mapping tool. He is also allowed to ask questions to the geoportal's support team and to read the FAQ. He CANNOT order products.
Unlike the “General Public”, the “client” has an individual user account associated to a password, which allows him to authenticate himself in the system. He has access to the “order” menu and can send orders or estimate requests concerning the available products in the catalog. In the order menus, he can check the state of his different orders and eventually download ordered files. For more information, please read the corresponding chapters in the geowiki.
The “Special Client” is also authenticated via his user account and his password. He has all the rights of the “client” but additionally, he can access to some specialized functions that require previous regulations. Depending on the granted rights, he can
The “provider” is the highest-ranking actor in the geoportal, thus the one with the maximum level of rights and functions. He generally has all the rights of a “special client” but has some additional rights / functions to
Subordinate accounts are used to delegate the management of the individual user accounts of customer organizations to one single main (« root ») account, without any interaction by the geoportal’s management. This means great flexibility for the customers as well as an easier task for the geoportal management team.
The owner of a root account can open new individual user accounts. Every single subordinate account can get all or a part of the special rights of the root account. Of course the root account cannot delegate more rights than it possesses itself.
The set of an organization’s subordinate accounts directly depends on the access rights of the root account, and the delegation of access rights can be done by switching on or off one or several items of the following:
On the upper left of the geoportal’s screen appears the login block.
Root accounts with active subordinate account function can create and manage subordinate accounts. This function is only available for the root account itself and not for the subordinate accounts.
The management of the subordinate accounts has 3 main aspects:
The subordinate accounts are organized in a tree-hierarchy, where the main branch directly depends from the root account. There can be as many sub-branches as needed by the root account.
Between the root account and the subordinate account the special rights detained by the root account can be passed on totally or partially. But among the subordinate accounts the tree hierarchy is a purely organizational one. There is no transfer of rights from one level of the subordinate accounts to another.
The user of the root account can :
This tag is the first to be opened when a new account is created. The empty fields have to be filled. When an existing account is opened, the contents of the settings is displayed.
Unlike the root account, the subordinate accounts do no have a section for the billing address, as they always act on behalf of the root account’s organization. The billing address of the root account is automatically used.
The properties of the “Contact” tag are:
The user can:
The name of the user associated with the account is mentioned on the top of tags to make sure the root account user is well aware of which account he is actually dealing with.
The properties of the login tag are:
The user can:
It has already been mentioned above that when creating new subordinate accounts, the root account can pass on all or part of its special rights to the subordinate accounts. To make things quite simple yet powerful enough, the geoportal offers transfer of rights with the following principles:
The following options can be activated:
After having logged in, every user can manage his account’s settings. This happens in the menu “my account”. Most of the functions are the same as those already described above for the subordinate accounts.
The properties of this tag are the same as those described above. Aditionnally there are fields for the billing address.
The user can :
In the menu “Maps and Products”, the function “Our Products” leads to the geoportal's product catalog:
This catalog opens on a static page, offering the choice between the different geoproduct categories and the multi-criteria search engine.
The following 3 categories are available:
In every category the products are listed in a catalog view:
The indicated information is :
The list is split into pages and can be sorted by:
With the multi-criteria search, it is possible to find available geoproducts by using different parameters.
In the alphanumeric part, the criteria are the following:
Spatial search : A little mapping tool is offered to define the geographic extent of the search. This can be done by drawing a rectangle in the map.
The navigation in the map is done by the following geographic functions:
Note: For the parcels which do not have any secondary number, it is automatically filled with 000000.
Note: For a parcel with the number 23/435, the user simply types 23 as main parcel number and 435 as secondary number. The fields are completed automatically.
The multi-criteria search presents the results in a list. Two buttons on the bottom of the page on the right allow to:
In case no product is found that corresponds to the search criteria, the initial search page is opened and the user is warned about the negative search result.
The catalog contains detailed information about the different geoproducts that are available in the geoportal. They are produced by the different providers who cooperate with the geoportal. The information sets are called metadata.
The metadata sets are accessed via the list of the geoproducts, by clicking on the product’s name. They are opened in a separate window.
The contents of the metadata sets respect the ISO 19115 norm. A selection of fields, which have to be filled in by the providers for each product, has been made among those proposed by the norm. This means that in the scope of the geoportal, for the first time in Luxembourg, a “luxembourgish metadata profile” has been established. This profile can later be used to exchange metadata with national and international instances.
Like all the contents of the geoportal, the metadata sets are normally available in 4 languages. The user chooses the language by clicking on the flag-buttons.
With the button “XML” , the user can get the contents of the metadata set in XML format (ISO 19139).
With the button “PDF” , the user can render contents of the metadata set in a PDF file.
The customers of the geoportal have access to the functions to create online orders of geoproducts.
The general principle of orders in the geoportal are represented in the following picture :
The online shop can be accessed in the geoportal’s main menu :
The 4-step ordering process is launched by clicking on the button “To Order”.
The 4 steps are:
The selection of a geoproduct happens in the catalogue itself:
( → more informations in section 6)
First the overall product category has to be chosen, or a multi-criteria search has to be launched. The results of the search is a list of the products with the following information:
The list is paginated and can be sorted following the name of the product or the providers.
Next to the links connected to the multi-criteria search (New search and Modify the search parameters), the user can :
Shortcut : the user can do the selection more quickly by directly clicking on the wanted product’s name instead of the caddie. This automatically leads to the next step.
In the 2nd step, the user has to define the geographic extent on which he wants to order the selected product. To do so, the geoportal offers several “order extent types” among whose the user may choose. The number and sort of these extent types depend on the product. For example Act’s 1/20000 map is sold only following the fixed TC20000 map sheets.
To be oriented in the geography, a mini-mapper is available offering the most elementary navigation and location functions of the main mapper.
If the user changes the extent type after a definition has already taken place, the procedure is initialized and a warning message appears :
Depending on the order extent type, the actions to be done can vary slightly. For this reason, in the following chapters every single order extent type is explained with its exact procedure.
A “Buffer” is a surface defined by a certain distance on both sides of a line. This can be useful when data is needed around linear axes like streets or rivers.
The order extent type “Buffer” is activated by clicking on the button
. Then the line of the buffer is defined in the map by clicking the respective vertices in the map with the left mouse button. Every point is represented in the map as a black square.
On the lower right of the screen, the coordinates of the points defined in the map are listed in the drop-down list.
After defining the line, the width of the buffer zone has yet to be fixed. The width in “meters” is entered in the field on the lower right :
The buffer is validated by clicking on the
symbol, and drawn in red transparent colour in the map for a visual control. After having defined the order extent, the user can move on to the next step of the ordering procedure by clicking on the button
.
Instead of clicking the points in the map, it is also possible to directly enter their coordinates. These coordinates are considered to refer to the actually active coordinate system:
With the button
, the coordinated typed in the fields are saved in the drop-down list on the right side. The
button can be used to delete the selected point from the list.
After defining the line and the width of the buffer, the buffer zone is validated with the
button and drawn in red transparent colour in the map to permit a visual control. After having defined the order extent, the user can move on to the next step of the ordering procedure by clicking on the button
.
With the order extent “Cadastral parcel” it is possible to define an order extent based upon a cadastral parcel. It is activated by clicking on the button
, and the order screen looks like shown in the picture below:
As shown in the example, the parcel is specified by providing the following information in the indicated order:
The pictures below illustrate the procedure:
With the button
, the data is validated and saved in form of the unique cadastral parcel code in the field below. The
button can be used to delete parcel from the list.
After having defined the order extent, the user can move on to the next step of the ordering procedure by clicking on the button
.
The order extent types of the “map sheet” kind are easy to use. When this order extent has been activated by clicking on the button , the different sheets are represented in the map window :
With a click on the button
, the choices are validated and the system searches the corresponding map sheet names in the database. The result is shown graphically in the map in form of red transparent map sheets, and alphanumerically as sheet names in the drop-down list on the lower right.
Instead of using the mouse to define the map sheets, it is also possible to directly enter the coordinates of the points in the fields :
With the button
, the coordinates are validated and saved in the drop-down list on the right. The
button can be used to delete the selected point from the list.
After validating with the button
the map sheets are searched:
After having defined the order extent, the user can move on to the next step of the ordering procedure by clicking on the button
.
The order extent types of the “map sheet” kind are easy to use. When this order extent has been activated by clicking on the button
, the different sheets are represented in the map window :
With a click on the button
, the choices are validated and the system searches the corresponding map sheet names in the database. The result is shown graphically in the map in form of red transparent map sheets, and alphanumerically as sheet names in the drop-down list on the lower right.
Instead of using the mouse to define the map sheets, it is also possible to directly enter the coordinates of the points in the fields :
With the button
, the coordinates are validated and saved in the drop-down list on the right. The
button can be used to delete the selected point from the list.
After validating with the button
the map sheets are searched:
After having defined the order extent, the user can move on to the next step of the ordering procedure by clicking on the button
.
After the product to be ordered has been chosen, a certain number of specific properties concerning the order request have to be fixed. This information enables the provider of the product to create and to deliver it conformingly. These parameters are entered in a form and the content of the form varies with the product. It is called “geoportal order form”. The following picture shows an example of the order form for the product “BD-L-TC complete (with attributes)“.
The order properties are organized in 4 chapters :
Next to the properties already described, it is possible that the order form contains more fields to be filled out. Indeed the provider may need other information for his internal management of the orders, than the intrinsic parameters mentioned above, and he can add the corresponding fields to the order form. For this reason an entire section “specific properties” exists in the order form.
After providing all the necessary information in the order form, the customer may proceed to the last step with the button
.
In the last step a summary lists all the parameters concerning the order or estimate request that have been fixed during the preceding steps The customer can check them before sending the request.
The customer can :
In case the customer is not yet logged in the geoportal, the following message appears :
[« Please authenticate by providing your username and password in the login block on the upper left of the page. Your order will be saved temporarily and be kept available when your identification has been done. »]
Using his password the user can log into the portal, and his order will be available to send. But it is important to notice that authentication is only possible for users who have been granted a username and password previously by Luxembourg’s Cadastre and Topography Administration ACT.
The anonymous user « general public » does not have the rights to send orders in the geoportal.
The authenticated user can manage his orders in the geoportal.
The order overview is opened with the “Trace my orders” button in the menu “Order” :
For every state, the number of requests is indicated in the overview.
If in a certain category no requests exist, the corresponding link is inactive and the indicated number is 0. The corresponding tag text is italic and the link is inactive.
By clicking on one of the active links either in the overview or in the tag titles, the corresponding tags are opened. They contain a table with the order and estimate requests of the category:
The order and estimate requests in the tag « drafts » are complete or incomplete requests that the customer decides to keep for later use. It is easy to use such a request to rapidly create a new request that can be sent.
The tag looks like this:
The information presented in the list is:
The list is paginated and can be sorted by:
Based upon an existing request in the list, a new request can be generated by clicking on the button
next to the request.
The customer can :
The following message appears:
« You are about to create a new order or estimate request based upon the selected request. Do you want to continue ? »
After validation with “OK”, the customer enters the 1st step of the order process. Every information in the 4 steps are kept an can be modified.
The request summary is opened in an new window:
In the tag “sent”, all the order or estimate requests that have been sent by the customer are listed.
The information presented in the list is:
The list is paginated and can be sorted by:
Based upon an existing request in the list, a new request can be generated by clicking on the button
next to the request.
In the tag “received” the customer finds the requests after their treatment by the providers. If the result of the order is a downloadable file, the download is done in this tag by clicking on the symbol
.
The information presented in the list is:
The list is paginated and can be sorted by:
Based upon an existing request in the list, a new request can be generated by clicking on the button
next to the request.
The downloadable files are contained in one single archive file which can be opened by clicking on the symbol
.
The following icons are used to inform the customer on the media used to deliver the ordered products :


The user can :
The customer con store his requests in his personal archive.
The information presented in the list is:
The list is paginated and can be sorted by:
Based upon an existing request in the list, a new request can be generated by clicking on the button
next to the request.
For the archived requests, the downloadable files under the symbol
remain available for a certain time before they are deleted. From the moment they are deleted, the link disappears but the information concerning the request remains available.
The user can :
In the “draft”, “sent”,“received” and “archived” tags of the order overview it is always possible to launch a new order based on an existing order or estimate request in one of the lists.
This can be helpful when doing multiple orders with small differences in the parameters.
The following paragraphs describe the procedure to follow.
In the list, click on the link
corresponding to the order you want to base the new order upon.
The following message appears:
After validation with “OK”, the first step of the ordering procedure is launched:
In this step it is possible to select another product.
If you do not want to select another product, you can immediately go further to the following steps:
In each step, the original settings of the order can be modified.
For example, in the order form (step 3), the fields are still filled with the original content, but can be modified to suit the new order. This way, a series of orders can be created very easily and efficiently, which may be useful especially when only few settings differ from one order to another (f.ex. order in shape format, dxf format and dwg format).
In terms of proper organisation, it may be useful not to forget to change the order name.
An authenticated customer can use the search tool to find old requests. This is done by clicking on the “Archive” button in the “order” menu :
The search screen offers the following parameters:
After the search, the presented information is:
The product and data providers that are linked to the geoportal generally have the following possibilities in the system:
A product and geodata provider of the geoportal, who offers products for sale in the geoportal, can handle the incoming orders of his products principally in two ways:
The following paragraphs explain the tasks of the providers concerning the incoming orders and estimate requests, in the case the orders are processed directly within the geoportal.
The tasks are:
To process the orders, click on “Handle the orders” in the menu “Providers”, in the function bar on the left of the geoportal page:
When this function il launched, a control panel of the ongoing orders, grouped by status, is displayed.
The order control panel indicates the active orders for each order status, either “to be processed” or “completed”.
The appearance and the handling are identical to the order control panel. Click on one of the status tabs or links to open the corresponding table containing all the orders in the selected state:
The tab of the orders to be processed looks like shown in the following picture:
The information shown in this list is:
The list is split into pages and can be sorted by:
The user can
… or click on an icon to open and process an order:
which specifies the order type and state
to proceed to the upload dialogThe information shown in the table is:
The list is split into pages and can be sorted by:
The user can click on the order number (link) to open the order summary which was saved when the order was sent.
Apart from the order details, the provider can find information about the customer, as it is shown in the picture below.
The information listed about the customer is:
The user can:
In the following paragraphs it is described how to manually process an estimate request or an order in the geoportal:
If the product provider has specified in the product settings that it is possible to require estimates of the product, the customer can use this possibility. When the provider has entered a price in the geoportal, this figure appears in the order summary, which then can be viewed by the customer after its updating.
Properties of the estimate:
The following messages can appear: “Please type a price for the order” → The provider has not yet typed a price “The price format is incorrect” → invalid characters
The manual processing of an order in the geoportal is similar to the processing of an estimate: click on the order number to open the corresponding dialog box.
Order properties:
The following messages can appear: “Please type a price for the order” → The provider has not yet typed a price “The price format is incorrect” → invalid characters
The product management tools are only available for user root accounts that have the status of a provider in the geoportal. With these functions, that are available under the main title “Provider”, it is possible to create, modify and manage the provider's own geoproducts in the geoportal. The main point
When the function “Manage the products” is launched, a table is opened with all the products of the provider. The contents and type of display are similar to the order control panel, also in terms of sorting functions.
The user (root account) can either select and open an existing product by clicking on the corresponding link in the list (for example to modify some settings of a product) or create a new product by clicking on the button “Create a new product” right on the bottom of the page.
When a new or an existing product is opened, a new page displays with 3 tabs:
In these 3 tabs all the definitions of a product in the geoportal are done. In case of a creation of a new product, the user has to go through all 3 of them in order to specify the parameters needed for the definition of the product.
The first tab contains all the main product definitions.
The following parameters have to be specified:
In the 2nd tab, the provider specifies the users within his organisation to which a certain responsibility of the product evolution in the geoportal is delegated. There he also decides about the visibility of the product.
He first specifies which user is responsible for the manual processing of incoming orders within the geoportal.
In the visibility part, he decides if the product can be orderd only within his own organisation (internal product), or if it can be ordered by anyone. The first option may be useful when new products are announced, to check and verify if the specifications are OK.
In the 3rd tab, the provider can define, modify and complete the order form to be used by the customer during an order procedure.
The order form consists of fields organised in a certain structure, designed to contain all the necessary information the provider's organisation needs to create the product. As every product has different specifications, this order form can be modified online by the provider in order to satisfy his needs.
The following pictures taken from an order form of a product of ACT, shows the structure of a form.
Several fields are mandatory for the system to work, independently from the product's specifications. Those fields cannot be deleted. In several sections it is however possible to interactively add new fields.
To configure the contents of a drop-down list of a field, f.e. of the field “Coordinate system”, click on the icon
next to the field. The following dialog box opens:
With the buttons », >, <, «, the elements can be inserted or deleted from the list “selected values”, and by this means, the drop-down list can be edited:
The procedure is similar in all the cases, where the contents of a list has to be modified. Next to the mandatory fields, it is also possible to add personal fields in the form. To do so, click on the icon
next to the section, where a new field has to be added. The creation of a new field happens in 3 steps:
Step 1 : Choice of field type
Step 2 : Contents in 4 languages and values
Step 3 : Summary.
Except from the mandatory fields, fields can be deleted from the order form by clicking on the icon
. It is also possible to edit the field definition by clicking on the icon
.
Metadata are textual information sets concerning geodata, webservices, products derived from geodata and layers in the mapping windows. They describe key elements like definition, whereabouts, actuality, quality, price, availability, responsibility etc.
Why do the providers have to type metadata in the geoportal ?
Geographic data in the geoportal is a digital representation of items of the real worls, used to show, analyse or otherwise use them in an IT environment. The use of geodata in many different fields of action is more and more widespread, and it has become easy to produce, modify and use this data. But it is important to know that these geodata are a more or less “imperfect” abstraction of the real world phonomenon, and not an exact duplication. To be sure that they are not used ina wrong context and to prevent eventual damage due to their use, it is important to provide all necessary information to the potential user, to give him the opportunity to evaluate if the geodata may convene to his needs.
The ISO 19115 norm defines a structure to describe digital geodata. It fixes the mandatory elements, the terms, definitions and procedures of this information. With its norm compliant metadata catalog, the geoporta offers a unique and central platform for the providers to describe their data and products in a standardised way. The metadata of the national geodata can be organised and managed efficiently, and users can obtain all necessary information to be able to use the data. What's more, discovery of data and products becomes much easier.
The provider has access to the metadata editing functions. In the menu “Provider”, the button “Metadata management” leads to the list of metadata draft sets the provider actually is working on.
The user can either click on “Create a new metadata set” to open the creation dialog and work on a new metadata set, or he can click on one of the icons next to an existing metadata drafts to - delete it - launch the INSPIRE conformity validation check - print it as a PDF document - render it as an XML file - send it to the geoportal and ILDG managment team to validate the metadata set and to insert it into the catalog - edit the metadata draft - crate a new metadata draft set based on the existing one
In the metadata editor, 9 tabs contain a long list of fields, compliant to the ISO norm, and selected to satisfy the INSPIRE needs as well as the national needs. They can be filled out depending on the field type : either free text or choices from lists or checkboxes.
The metadata draft can be saved, and exists as metadata draft set as long as no validation has been requested. It can be edited by the provider, modified, deleted and used as base for new draft sets. Using the icon
the set can be sent to the geoportal management team for validation. In case validation occurs, the metadata set is activated in production and no longer available in the list of draft sets of the provider. He always can access his metadata set in the public catalog and either copy it or generate a new version, if he wants to update it.
Providers of the geoportal can have their own geodata published in the mapping tools of the geoportal.
Quite contrary to the creation of new products, this publication cannot be done autonomously by the provider. Indeed the system architecture needs the interaction between both the provider and the system administrators.
The following steps are necessary:
When a provider wants to publish own geodata layers, he decides together with the responsible persons at ACT about the access conditions to his data in the mappers. He also decides about the names of the layers in the 4 languages, and about the main themes the layers should be classified in.
These decisions are added to the written common agreements between ACT and the provider.
Providers should create OGC compliant webservices of their geodata (WMS) and give ACT access to them. ACT uses the webservices to add the data to the mapping tools
- by integrating the webservices in the “old” mapping tool (RedSpiderWeb technology)
- by using the webservice to calculate tile caches for the general public viewer map.geoportail.lu
In case of technical problems, ACT may offer its help to create the webservices. If no technical means exist at the provider's organisation, it is also possible to deliver the data to ACT. In this case, the geoportal department creates the webservices and does all the necessary actions to publish the geodata.
Each provider of products and geodata can publish own geodata webservices and use the access control layer provided by the geoportal webservice proxy.
For a better understanding, the difference between viewing geodata layers in the geoportal's online mapping tools and retrieving geodata contents via online access to webservices should be explained:
Whereas the mapping tools are designed to run within an internet browser - with the duly reduced functionality palet - the geoportal also offers an interface for professional GIS applications to directly connect to the geodata via standardized webservices.
This connection is only possible if
The geoportal offers a great choice of webservices, part of which are protected by ghe geoportal's internal access control system. Of course every provider is free to publish his geodata independently from the geoportal, but he can also choose to integrate his webservices with the access control layer of the geoportal, instead of investing himself in such a system. In this case, his webservices are published with an URL of the geoportal, and they are accessed via the geoportal's “OGC proxy”.
This connection to a proxy can actually be done for WMS services as well as for WFS services.
The geodata webservices can be made available either to the general public, or to a precisely defined target user. This happens through detailed OGC access profiles in the geoportal's management system. The restrictions to be implemented in the profiles are decided by the provider and ACT in common.
This publication of geodata content via the OGC proxy can of course not be done by the provider himself. It needs co-operation between the data provider and ACT.
The steps to publish new geodata layers via the geoportal are the following:
When a new user joins the geoportal as geodata and product provider, he decides together with the responsible persons at ACT which geodata layers he wants to publish on form of an integrated WMS or WFS webservice, as well as the possible restrictions he wants to be applied upon his webservices. There may be supplementary issues to discuss, like for example the possibility to allow reprojections in other SRS by the proxy, or the data rendering in different file formats.
These decisions can be documented in the written agreement which is signed between the representatives of ACT and the provider organisation, when the user account is opened.
The access restrictions that can be offered by the geoportal for the “proxied” webservices, are the following:
The provider can always ask ACT to change the settings of the access restrictions. In this case, the written agreement has to be adapted.
Le géoportail est entièrement construit sur la base d'échanges de données selon des spécifications et normes en vigueur, notamment sur l'utilisation de webservices normalisés basant sur la spécification WMS (Web Mapping Server) de l'OGC (Open Geospatial Consortium).
Pour publier un tel webservice à l'aide du proxy WMS du géoportail, le fournisseur doit d'abord mettre en place un tel webservice conforme à la spécification WMS. Il a le libre choix des softwares propriétaires ou open source qu'il entend utiliser pour ce faire. L'essentiel est la capacité du service de répondre aux appels normalisés selon la norme WMS.
Il doit ensuite fournir à l'ACT les informations nécessaires pour accéder ce webservice, comme l'URL et les données nécessaires pour la sécurisation (mot de passe). L'ACT procédera à des tests d'intégration du webservice, en respectant les spécifications retenues dans la convention sus-mentionnée.
L'ACT pourra essayer d'assister le fournisseur dans la résolution de problèmes relatifs aux webservices OGC.
Après avoir effectué des tests concluants, l'ACT ajoute les nouveaux webservices en provenance du fournisseur dans le proxy WMS du géoportail.
Les nouvelles couches pourront être accédées de la même manière que les autres webservices disponibles, moyennant protection par mot de passe.
Comme il est mentionné au chapitre 6.2 du présent manuel, le guichet cartographique est alimenté par des couches de géodonnées provenant de webservices normalisés qui reposent sur les spécifications WMS (Web Mapping Server) et WFS (Web Feature Server) de l'OGC (Open Geospatial Consortium). D'autre part, les géodonnées peuvent aussi être fournies directement via des webservices accessibles à des applications SIG clientes, tel qu'il est décrit au chapitre 7.
Dans le présent chapitre, les différents aspects quant à la mise en œuvre des webservices WMS pour le guichet cartographique ou le proxy WMS du géoportail sont explicités.
Le texte décrivant la spécification WMS est téléchargeable sur le site http://www.opengeospatial.org/standards/wms. Cette spécification a été reprise par l'ISO sous la norme ISO 19128.
Qu'est-ce qu'un service WMS ? Un service WMS est une application informatique tournant sur un serveur connecté à un réseau informatique (comme p.ex. un intranet d'entreprise ou plus généralement l'internet), qui fournit sur demande, et de manière dynamique, des cartes contenant des données spatiales à partir d'informations géographiques (ou géodonnées). Ce rendu graphique des géodonnées se fait à travers un fichier informatique dans un format utilisable pour un affichage à l'écran, généralement des fichiers image raster comme les PNG, GIF ou JPEG. Le fichier contenant la carte ne représente PAS les données elles-mêmes ! Par contre il peut être utilisé pour un affichage dans l'application cliente.
Comment fonctionne un service WMS ? La norme WMS définit trois opérations de base dans le fonctionnement du service WMS. La première opération s'appelle “GetCapabilities” et permet à tout client qui s'adresse au webservice d'obtenir toutes les informations techniques (metadonnées) sur le contenu que peut fournir un webservice, ainsi que sur des paramètres techniques comme le format des fichiers fournis, le système de projection cartographique, l'étendue géographique disponible, le genre de données etc.
La deuxième opération s'appelle “GetMap” et elle permet de demander au webservice de produire un fichier contenant une carte, en lui spécifiant l'emprise géographique (la “BoundingBox”, càd l'endroit géographique défini par un rectangle Nord-Sud, à travers les coordonnées des points-limite), le système de projection, les couches de données ainsi que des paramètres techniques variant selon le besoin (p.ex. taille de l'image rendue, transparence et couleur de l'arrière-fond). Un exemple d'une telle “requête” au webservice peut être :
| http:\\ecadastre.public.lu:8081/public/wms/pcn?VERSION=1.3.0&REQUEST=GetMap&CRS=CRS:84&BBOX=97.105,24.913,8.794,36.358&WIDTH=560&HEIGHT=350&LAYERS=(…liste des noms des couches…)&STYLES=&FORMAT=image/png&EXCEPTIONS=INIMAGE |
La troisième requête de base est l'opération GetFeatureInfo, qui permet de demander des informations alphanumériques (attributs) sur des entités graphiques (features) particulières représentées sur la carte.
Un WMS organise les contenus livrés sous forme de “couches”, et peut offrir des “styles” de représentation graphique différents, au choix du client qui invoque le service.
Le fournisseur a le libre choix des softwares propriétaires ou open source qu'il entend utiliser pour ce faire.
Il doit ensuite fournir à l'ACT les informations nécessaires pour accéder ce webservice, comme l'URL, et les données nécessaires pour la sécurisation (mot de passe). L'ACT procédera à des tests d'intégration de ces géodonnées, en respectant les spécifications retenues dans la convention sus-mentionnée.
L'ACT pourra essayer d'assister le fournisseur dans la résolution de problèmes relatifs aux webservices OGC.
The geoportal is an exchange platform of geodata, geoproducts and geodata webservices.
If one or several clauses in the present conditions of use are considered invalid, or declared to be invalid in conformance to a law, a regulation or a juridictional decision, the other clauses remain valid.
Except for a formal permission of ACT's director, the geoportal may not be integrated by whatever means, entirely or partially, in another web site, for example through framing or inlining techniques.