WEB COVERAGE AND GEORREFERENCED IMAGE SERVICE FOR THE SPATIAL DATA INFRASTRUCTURE OF THE REPUBLIC OF CUBA AND APPLICATIONS Author and co-autors Eng. José Luis Capote Fernández, M.Sc. Eng. Rafael Cruz Iglesias, Grad. Guillermo González Suárez, Grad. Osmani Herrera González, Tech. Liset Becerra Lugones Affiliation GEOCUBA Enterprise Group Contact: [email protected] ABSTRACT At the present time it is difficult the access to the geographical information, including satellite images and digital models of phenomenons of different types. These difficulties include the high cost in the acquisition, the great size of the information that hinders the transport and the distribution, and the lack of knowledge of the sources of that information. Due to this in many occasions the space variables are not considered resulting in non appropriate decisions. To give solution to this problem it is necessary to coordinate from a government level all the actions with respect to not only facilitating the access to these data but also the publication and the compartment of the same ones. In Cuba the Spatial Data Infrastructure of the Republic of Cuba (IDERC) takes charge of these functions. In the frame of the IDERC has been developed a group of technologies guided to allow the access shared to the geographical information in an Internet environment. Based on the existence of a Internet Map Server that allow the publication of information in vectorial format other new potentialities are included oriented to the manipulation of raster data and the publication of these as images as well as to the publication of cosmic images. Several projects of investigation about some of the specifications emitted by the OpenGIS consortium have been developed . Also was implemented the specification of the format GeoTIFF. This previous work allowed the creation of a service of images in format GeoTIFF for Internet using the specification 1.0.0 of Internet map servers. A web coverage service was implemented based on the specification 1.0.0 that it allows to serve raster data, and the specification Portrayal Coverage Service that allows the visualization of coverage data like images applying predetermined classifications and other ones defined by the user. In this work we present technical elements of the development of these technologies and of the interaction among them. Examples of applications are shown that make use of these technologies guided to different addresses and developed by different institutions what will surely have a considerable impact in the quality of the taking of decisions. INTRODUCCION The rapid prosperity of Internet and the increment of the connectivity among computers at global level has provoked the necessity of a search of informative technologies that allow to take advantage of these communication facilities. The use of the information distributed in the net to give solutions related with a specific topic provides an incredible advance in terms of administration of the knowledge. And if to the use of information based on the traditional data types we join the one based on geospatial data we can obtain a new vision of the problems and a new spectrum of solutions. The use of spatial information has experienced a peak in the last years. The development of new survey methods based on the remote perception has given a great impulse to this thematic. In Cuba is broadly diffused the use of air and satellites images to carry out surveys of different nature that can go from cartography generation to environmental studies. These images take a previous process to their use that includes processes of improvement, georectification and georeferenciation to eliminate some deformations and to adjust it to a spatial reference system. During some years this process was carried out and its results were the obtained image and a file or document with the parameters of this image. The format GeoTIFF eliminates this separation between the image and its parameters when inserting in the same one a group of labels that contain them. The specification GeoTIFF is made over the format TIFF in the version 6 and it doesn't contradict for anything to the same one. It admits compression for different methods and monochrome, gray scale and true color images. For the possibilities before described this format is broadly used to store georreferenced images. The enterprise group GEOCUBA as results of previous investigation projects have an implementation of this format. This implementation allows to visualize images GeoTIFF in all its resolution variants. They have been carried out tests with GeoTIFF emitted by different applications used to generate them. The Internet map servers don't only allow to publish maps of certain projects. They can also be used to share images among the different participants of an investigation without necessity of duplicating the same one or of overloading the net opening up from a remote location an image of great size. It also avoids an administrator of projects the work of to maintain updated the participants every time that are renewed the images. In the frame of the IDERC has been developed and collected a group of technologies guided to allow the access shared to the geographical information in an Internet environment. Based on the existence of a Internet Map Server that allow the publication of information in vectorial format other new potentialities are included oriented to the manipulation of raster data and the publication of these as images as well as to the publication of cosmic images. Also a Web Coverage Server and a Web Portrayal Server is provided to allow the creation of on line clasiffications of theese data and the visualization of theese. In the frame of the IDERC has been developed and collected a group of technologies guided to allow the access shared to the geographical information in an Internet environment. Based on the existence of a Internet Map Server that allow the publication of information in vectorial format other new potentialities are included oriented to the manipulation of raster data and the publication of these as images as well as to the publication of cosmic images. Also a Web Coverage Server and a Web Portrayal Server is provided to allow the "on line" classification and visualization of these data. DEVELOPMENT 1. GEOTIFF FORMAT. Elements of the specification The format TIFF has become one of the formats of files more popular raster in the world. But TIFF is limited in cartographic applications because there is not an openly available stable structure to cover the geographical information that at the moment exists in the public domain. Some private solutions exist to store cartographic information in the labels of the files TIFF. Intergraph has developed a group of geographical labels for the TIFF that at the present time they conform a robust and mature implementation, but it is only usable in its applications. The same thing happens to ESRI and Island Graphics that possess limited own geographical solutions to applications you specify to their software architectures. Many companies GIS, supplying of data raster, and their clients have requested to the companies responsible for the supply and the exploitation of these geographical images a platform standard interoperable for the support of geographical images in format TIFF. This way the images could originate from platforms of images satelitales and air, paper maps and the result of geographical analysis. The images TIFF that are supported by the specification of Intergraph will be read and positioned correctly in any system GIS that this new standard called GEOTIFF supports. The saving to the users and suppliers of data raster and of software of exploitation it is potentially significant. With the platform GEOTIFF, the companies can stop of spending excessive resources of support development to anyone and all the formats proprietors that have been invented. The suppliers of data will be able to produce images at a lower and quicker cost. The final users will have the developed software advantage them to exploit the transparency of the labels of the format GEOTIFF. And the most important, the same image raster TIFF that can be read and modified in an ambient GIS it can be equally exploded in another ambient GIS without requirements of duplicity of files or of operations of caring / to export. The specification GEOTIFF defines a group of labels to describe all the geographical information associated with an image TIFF originated from systems of satellite images, air pictures and scanned maps, digital models of elevation or as the result of a geographical analysis. Their objective is to facilitate a means to link an image raster to a model of the well-known space or map projection, and to describe these projections. The format GEOTIFF fulfills totally the specification TIFF 6.0 and its extension doesn't go in any sense against the same one, neither it limits the reach of the data raster supported by TIFF. GEOTIFF uses a small group of reserved labels TIFF to store a wide range of georeferenced information, supplying to the systems of coordinated geographical and projected of the data that are needed. The projections include UTM, US State Mourns and National Grids besides the projections base as they are they Traverse Mercator, Lambert and others. No information is stored in private structures, or another mechanism that hides information to the software reader of TIFF. GEOTIFF uses an approach "MetaTag" (GeoKey) to code dozens of elements of information in only 6 labels, taking the advantage of the format of representation of data TIFF, independent of the platform, to avoid exchange difficulties among platforms. These keys are designed in parallel form to the standard labels TIFF, and they follow the discipline very closely TIFF in their structure and design. New keys can be defined chord to the necessities that are needed inside the mark of current work and without requiring the location of new labels in the standard TIFF.