MobilDat - Mobile Data Visualisation And Updating Karel Charvat1, Milan Konecny2,Petr Kubicek2, Karel Stanek2, Petr Horak1, Milan Kocab3 Pavel Vanis 3, 1, Wirelessinfo, Cholinska 1048/19, Litovel, 78401, Czech Republic Tel: +420604617327, Fax: +420281973501, Email:
[email protected] 2 Laboratory on Geoinformatics and Cartography, Faculty of Science, Masaryk University, BRNO 3 VUGTK, Zdiby 98, CZ-250 66, vCzech Republic
Abstract. The goal of MobilDat projects project is to join to design and implement innovative mobile solution and mobile visualization for sharing and updating of spatial knowledge with special focus on forestry. The focus is not only on direct technological development but also on interoperability and standardization methods and tools for mobile data management. The main principles of such solution are: •
To define and implement standards for sharing of knowledge in mobile data updating.
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To build system on Mobile Web platform, such solution allowed offering access to information from any place and any time. Internet platform support universal data access using fixed and mobile connection and also offer basic communication interface for all applications
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To use open platforms for building of this system and all its components. Only open platforms allow to build such universal solution, which will support effective development of such universal system and also future development
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To define process models for defined groups of user and on the base of this functionality defines user profiles. The system of user profiles allow to prepare special solution for every group of user and very easy work with complex system
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to create contextual visualisation of the user interface and the mapface content to update paricular map feature
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To combine effective tools, which will offer information access, but also analytical tools, which will offer complex data analysis
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To implement metadata model as effective tool for managing of knowledge, this will be able to describe all available data source, including data validity, data history and data source in all process. The metada records will attached automatically or semi-automatically during data capture or update.
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To offer possibilities of access to distributed data source and so increase effectively of data access and data analysis. Using distributed data source is way of future more effective systems. From second side it request to build interoperable system, which allow this. The possibility is use OGC standards.
Keywords. Mobile visualization, mobile data updating, spatial knowledge
Introduction New sensors could improve measuring and controlling of all management processes in agriculture and forestry production. Important tool, used for many analyses is the Geographic Information System (GIS). In connection with on line wireless data access, it can bring new quality into controlling process. Such systems enable to gather and analyze effectively all available data on the landscape and based on these analyses to elaborate recommendations for agricultural production regulations. The main requirement is the creation of a mobile field data collecting user-programmable system with a further updating possibility. The user-programmable system shall be based on open formats and structures and shall not be strictly bound to one device type. The system is developed both on OpenSource platforms and shall contain both common mapping tools and special utilities aimed clearly to problems solved in agriculture and forestry.
This system should allow first of all: • Use of existing data sets for data collection • Integration of Earth Observation data into the process of data collection • Transformation of data to user-defined structure. • Connecting the system to other special purpose devices supporting data collection. • Connecting spatial data with photo documentation • Connecting the system to map servers – query systems and update systems. • For a component based architecture, allowing building different applications from the simplest (for example just for GPS data collecting) to the applications with maximum functions. The goal of solution is to connect mobile solution with analytical tools and to support mobile knowledge management. The developed architecture is based on previous experience from WirelessInfo, Premathmod and ReGeo project, but there are implemented new principles. The designed solution will be based on service model; the basic principles will be implementation of OGC recommendation, which will support exchange and sharing of spatial data and also services
Use case description There were identified number of tasks and the use cases were defined by project partners from pilot regions. The use cases cover the tasks, which the partners want to solve in MobilDAt project. General use cases were made on base of specified use cases which have similar or the same solution. We use the use of the “Standard Use Case Template”. The focus is mainly on customisation of the general OAS model to concrete services and to find similarities in practical terrain analysis in everyday work in different user domains. The interviews with users demonstrate, that there exist basic modules, which fulfil general user needs, but have to be modified. The user access for collecting information about forest management and agriculture measurement are differences are in used sensors. Next table demonstrate one from examples of use case description. Use case Inventory plot survey Company Forest Management Institute Actors Operator Task Forest inventory (FI) plot localization (FI network, region, district, Natural forest region), description of accessibility, plot permeability, relief, altitude, ownership, (kind of plot ownership, user relation) forest category, group of the forest site types, altitudinal zones, names of inventory group members, date of measurement. Assumptions
Maps: The inventory squares and plots network, management map raster + contour lines block, maps of cadastre, Natural forest regions, forest categories, typological map, regions and districts boarders, altitudinal zones , ID of inventory plots, coordinates of main and substitution centres of inventory plots Code lists: by Forest Inventory methodology Measuring tools: Hammerhead computer or compatible
Description
Data collection: All data are set by operator, no parameters are measured. It is possible to predefine following within office preparation: region and district, Natural forest region, forest category, altitudinal zones. Other items can be only set or at least verified (group of the forest site types) in field
Issues On the base of use case description, the general UML model was designed.
Examples of solved basic tasks
Sketch The sketch is usually symbolic record of the situation made by draws. In case of MobilDat we 4TH WORLD CONGRESS ON COMPUTERS IN AGRICULTURE
understand under sketch a composition of draws and symbols which enrich geodata record either by complex information about geometric and semantic relation ship to other existing objects or some information about recorded object itself. Main purpose is to preserve consistency of geodatabase after capture new record or update existing one. In field is very difficult to describe complex characteristics of objects, but such description is necessary, therefore sketch is most convenient way how to attach information to the object and not to exaust an operator with. Sketches cover several areas of object attributes some of them are preprocessing – during capture and some of them are postprocessing – when the operator check automated update done by system.
Mobile fotodocumentation The Photodocumentation can be used like additional information for a postprocessing of fieldworks. Dedicated person can easy check results of terrain workers without physical check in-situ. Especially when some inconsitencies of the geodatabase appears after updates. Moreover photodocumentation can bear more information then was recorded during fieldworks and can be retrieved later in case of a need. In case of Mobilldat is photodocumentation equped with standad metadata record and an approximate spatial extent of the visible area. Perspective approaches in the photodocumentation area are horizontal stereopairs, which allows distance measurement from photography.
Technological solution
Basic architecture Using UML modelling, general model for the MobilDat system was designed dd Deployment Model
Internal Serv er : Serv er
«TCP/IP»
External Serv er 1 : Serv er
«TCP/IP»
Extarnal Serv er 2 : Serv er
External Serv er 3 : Serv er
«TCP/IP»
Application Serv er :Serv er
Broker
«TCP/IP» «GPRS, WiFi» Desktop client :PC
Proj ect Editor
Desktop Proj ect Processor
Desktop GIS Editor
«Various» Mobile client :PDA MU :Mobile Unit Mobile Proj ect Processor
Mobile GIS Editor
External Dev ice Manager
«BT,WiFi»
«RS232,USB,...»
«BT»
ED 1 :External Dev ice
ED 2 :External Dev ice
Which cover most from basic task. There are expected different tasks of collection of information using this general model.
Hardware solutions We suggest the following four hardware combination possibilities to test the mobile client 1. Professional PDA device with GPS, external communication (for example Trimble GeoXT) often use in data collection by field workers in hard conditions 2. Compact PDA with GPS and GPRS/EDGE (for example HP iPAQ hw 6515 Mobile Messenger (FA384A)) - use in controls, time-by-time data collection, free time activities 3.
PDA with GPRS/EDGE, external GPS (for example HTC Wizard (T-Mobile MDA Vario, Eurotel Qtek9100)with GPS ASUS Solar) 4TH WORLD CONGRESS ON COMPUTERS IN AGRICULTURE
4.
- use in controls, time-by-time data collection, free time activities, debugging of the communication GPS-PDA by Bluetooth TabletPC, external GPS (for example Toshiba Tecra M4-103 with GPS ASUS Solar) - professional work and data collection in less hard conditions (town) testing of new technology advantages (PDA & notebook alternative)
GPS technology Mapping GPS receivers allow to transfer data for processing to computer in NMEA 0183 format, and in firm format and in RINEX format. Thanks to this it is possible to refine these data by differential corrections applied while follow up data processing at office. Range of passed data is in this case given by RINEX format specification and further speculations are useless. In case, that we don’t have data from GPS receiver in RINEX format, the problem of parameters categorization of GPS receivers inputs for three other users group may be summed up by following: • GPS receiver must offer data of position and measurement time and also data of movement speed and azimuth, which may be interesting mostly for some precision farming jobs • Furthermore it must offer PDOP data for single surveyed points, so that it is possible to judge obtained geodata quality • Furthermore it would be suitable if receiver offers the list of satellites, that were used for setting position or at least the list of actually available satellites. • Precise parameters of each satellite orbits • Number, azimuth and elevation of each actually available satellites • Almanach
Communication solution In Mobildat is designed a heterogeneous communication network based on the next elements • PAN using blue tooth • WLAN based on WiFi • WWAN based on GPRS (or eventually EDGE) Bluetooth technology is used to create a short range connection among various devices. Bluetooth is a short range (30 feet) radio technology operating in the 2.4GHz band with transfer speeds up to 1Mbps. Bluetooth is showing up on a number of today’s new devices, including desktop and laptop computers, printers, peripherals, personal digital assistants (PDAs), and phones, allowing these devices to "network on the fly" and share information. While general acceptance is somewhat limited at the present time, look for this technology to show up in more and more of the latest consumer electronic devices— everything from automobiles to refrigerators in the near future—wherever short range connectivity is required GPRS is designed to support intermittent and bursty data transfers and occasional transmission of large volumes of data, and point-to-point and point-to-multipoint services are supported too. EDGE enables services like multimedia emailing, Web infotainment and video conferencing to be easily accessible from wireless terminals. EDGE is designed for migration into existing GSM and TDMA networks, enabling operators to offer multimedia and other IP-based services at speeds of up to 384 Kbits/s (possibly 473 Kbits/s in the future) in wide area networks. An important attraction of EDGE is the smooth evolution and upgrade of existing network hardware and software, which can be introduced into an operator's current GSM or TDMA network in existing frequency bands. The WIFI technology often is also identified or referred to by its IEEE standard designation of 802.11. The 802.11 standard is actually a number of different specifications that operate at various speeds, frequency bands and distances. The popular standards in use today include:
Conclusion There is currently developed new systems as a part of two Czech national research projects Mobilat The simgle components of Mobildat were already implemented and currently the integration is running.
References Konečný at all. Mobildat / Annual report in Czech Caduff (2002): Sketch-based Queries in Mobile GIS Environments. Master Thesis, University of Maine. Green (2003): Quick Study Guide: Going Mobile: Mobile Technologies and GIS. University of Aberdeen 4TH WORLD CONGRESS ON COMPUTERS IN AGRICULTURE
Guth (2002): Metodika mapování biotopů soustavy NATURA 2000 a Smaragd (metodika podrobného a kontextového mapování). AOPK Praha. Hassin (2004): MOBILE GIS: HOW TO GET THERE FROM HERE.
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