The monitoring of snow cover extent is important for the management of natural resource, extreme events prediction such as snowmelt floods, avalanches etc. The current status is that the network of weather stations is too sparse in regions with seasonal snow cover to provide reliable snow monitoring and impact applications. Remote sensing can regularly provide maps of snow cover extent, under limitations imposed by satellite cycles or cloud cover. A number of daily or synthesis snow cover extent products, covering Romania, with different resolutions and specifications, are available for free (e.g. GLOBSNOW, CryoLand, H-SAF, IMS). These products were homogenized and included, along with reference and in-situ data, into an application that make possible for user to inspect, process, analyze and validate the information, using a web based interface. The platform, created by National Meteorological Administration of Romania offers services based on Open Geospatial Consortium standards for data retrieval (WMS, WCS, WFS) and server-side processing (WPS, WCPS). The services were built upon open source solutions such as GeoServer, OpenLayers, GeoExt, PostgreSQL, GDAL, rasdaman. The application is composed of several software modules/services. The modules are split into two categories: server-side modules/services and client side modules - responsible for interaction with the user. A typical usage scenario assumes the following steps:
1. The user is operating the client functionality to select a temporal and spatial slice from a product cube (e.g. 5 months archive of daily CryoLand FSC data);
2. The users select a statistic method to be applied;
3. The request is sent to the server side processing applications wrapped as WPS or WCPS calls;
4. The process will trim/slice the coverage cube, perform the statistic operation for the pixels within the ROI for each day in the selected time interval;
5. The results are sent back encoded in a standard file format;
6. The web client display the results in a relevant form. |