W42 - a scalable spatial database system for holding Digital Elevation Models

The design of a scalable system for holding spatial data in general and digital elevation models (DEMs) in specific has to account for the characteristics of data from various application fields. The data can be heterogeneous in coverage, as well as in resolution, information content and quality. A database aiming at the representation of world-wide DEMs has to consider these differences in the design of the system with respect to the structure and the algorithms. The database system W42, which is presented in the work at hand, is a scalable spatial database system capable of holding, extracting, mosaicking, and fusing spatial data represented in raster- as well as in vector-format. Design aspects for this task can be specified as holding spatial data in unique data structures and providing unique access functions to the data. These are subject of this work as well as first experiences gained from the implementation of part of the extensions made for the TanDEM-X mission

The EnMAP Ground Segment user services and products

EnMAP (Environmental Mapping and Analysis Program) is a high-resolution imaging spectroscopy remote sensing mission dedicated to monitor and characterizing Earth's environment by providing accurate information on the state and evolution of terrestrial and aquatic ecosystems. EnMAP is equipped with a prism-based dual-spectrometer, which can make observations in the spectral range between 418.2 nm and 2445.5 nm with 224 bands and a high radiometric and spectral accuracy and stability. The EnMAP satellite was launched on 1 April 2022 and completed its commissioning phase in November 2022. From March 2023 EnMAP accepts user requests to acquire new acquisitions or download products from the mission archive. The EnMAP Ground Segment, under the responsibility of the German Aerospace Center (DLR), provides the services necessary to command the satellite and receive, archive and process the EnMAP data up to the three user product levels that can be ordered. These products are the radiometrically corrected at sensor top-of-the-atmosphere radiance product (L1B), the radiometrically corrected and orthorectified top-of-the-atmosphere radiance product (L1C) and the atmospherically corrected bottom-of-the-atmosphere reflectance product (L2A). The L2A processing supports options for Land processing, Water processing and a combine mode that automatically selects the correction based on pixel classification. In this contribution we offer an overview of the services provided by the EnMAP Ground Segment to the EnMAP data users: planning of new EnMAP acquisitions, access to archived data products and data processing. We cover in particular those aspects that, according to the user feedback, have been more challenging for the EnMAP users. We also provide an overview of the EnMAP products available and the different access or processing options that users can choose from

The Ground Segment of the EnMAP Mission: from Tasking to Product Download

An overview of teh EnMAP Ground Segment services of interest for the users of the EnMAP data products

The EnMAP Observation Planning and Data Access for Scientific Users

EnMAP (Environmental Mapping and Analysis Program; www.enmap.org) is the first German imaging spectroscopy mission, to be launched in April 2022. After its Launch, Early Orbit and Commissioning Phase (6 months), the EnMAP mission will be available to the international user community for the data access and ordering process. EnMAP will be operated by the German Aerospace Center (DLR) covering all aspects relevant to assure successful mission operations. This comprises controlling and commanding the satellite using multi-mission infrastructures as well as observation planning, data reception, hyperspectral data processing including calibration, data archiving, data access and delivery, and providing web-interfaces to the international user community. This presentation will give an overview of EnMAP observation planning and data access concepts and outlines the data ordering workflow in particular for scientific users. The user can get access to EnMAP data using two different order options: On the one hand the user can submit future order requests through the EnMAP Data Access Portal (EDAP). The EDAP links to a set of functions for registered users that will support the international user community. This portal includes amongst others the proposal portal allowing submission of proposal for all scientific users responding to a Data Announcement of Opportunity (AO) and the Observation Request Portal providing planning support of observation requests and allowing submission of future orders. On the other hand, the already recorded data can be searched, processed and delivered based on catalogue from the archive through the EOWEB® GeoPortal. Although EnMAP is based on an open data policy and every type of user is in principle entitled to download data and request acquisitions, there will be different user categories to set acquisition priorities. The scientific (Cat-1) orders has higher priority and is requested to submit a proposal, which will undergo a scientific evaluation. The associated results will be presented by an interactive map supporting the establishment of a worldwide user network and guarantee the highest transparency of the proposal process. In the Observation Portal the user is able to submit future order requests by specifying following order parameters, such as the geographic area of interest (AOI) (between 74° North and 74° South), length of the AOI as a multiple of 30 km and up to 1000 km, the specification of the maximum allowable tilt angle of the satellite across the orbit (5° to 30°), the time span in which the acquisition should be performed and the option for time series and the number of data takes per months. To ensure acceptable illumination conditions, only images with sun zenith angle lower 60° will be considered. As for data acquisition EnMAP will be able to collect 5000 km along track and 30 km across track per day. The probability that the order will be included in the mission planning depends on the requirements for the observation as well as the specified priority and quota. Whether a specific data take is scheduled at the end depends on factors such as e.g. available data storage, cloud probabilities (e.g. historical and predicted cloud coverage) and, if requested by the user, sunglint probability (this is relevant for water products only). Users should make a request at least 25 hours before the scheduled recording to ensure the uplink. All data are available no later than 24 hours after collection for further processing into data products. The EnMAP ground segment will provide a range of standardized data products with different levels of processing of Level 1B, Level 1C and Level 2A based on archived Level 0 comprising extensive quicklooks and metadata. Due to required multiple processing options, each product is generated specifically for the order and delivered using FTPS (FTP with SSL) provided by multi-mission facilities

User Inquiries and Ground Segment Operation Activities

Since the beginning of the operational phase in November 2022, the Environmental Mapping and Analysis Programm (EnMAP) has gathered substantial interest within the Earth Observation community, counting a considerable number of more than 1800 registered users from over 80 different countries across the globe. The EnMAP data archive is also used very frequently by users with ordering and downloading approx. 2000 tiles per months. Any science user can submit its (his/her) own observations request via the EnMAP Instrument Planning Portal (IPP, https://planning.enmap.org/, also reachable through the official website www.enmap.org), by submitting a proposal. The IP portal also provides access links to the entire EnMAP data archive via the EOWEB Geoportal. The number of users requesting future observations varies significantly based on geographic location. Notably, Europe sees the highest demand for the EnMAP mission, leading to challenges such as conflicting orders for areas within the same orbit. This convergence has introduced complexities in data acquisition, particularly for time series and orchestration of field campaigns. To ensure (increase) regular data acquisition and boost mission efficiency, a "Foreground Mission" has been introduced. This entails prioritized acquisition of extended 990-kilometer flightlines (stripes) over Europe, with a specific focus on Germany. This strategic approach aims to improve data coverage in Germany and streamlines recurring acquisitions along key transects. First this informative presentation provides an assessment of ground segment operations, with special attention given to user feedback and inquiries. Along the way, it outlines the most prevalent user concerns and highlights the strategic factors involved in requesting observations. As second part the audience gains deeper insight into the newly implemented Foreground Mission initiative