DATA ACQUISITION AND VALIDATING OPERATIONS WITH MOBILE GIS TECHNOLOGY

Valerio Zunino
Istituto Universitario di Architettura di Venezia
Diploma Universitario in Sistemi Informativi Territoriali

The slow process of renewal that is in progress in the Local Administrations and as for other subjects who are concerned with the use of GIS technology in all the different operative directions, is going to produce encouraging outcomes in all those official organizations which have invested in a better way (and probably before) in the four components of the System (hardware, software, data and human resources) and that have been able to ask the question and at times prefigure structural and applied sceneries by a medium-time optics.

Inside of some of these organizations we can notice the development of GIS peripherical systems which are concerned with the survey and with the capturing of territorial information at source. The Mobile GIS” is going to become one of the most outstanding evolutions in many applied sectors where the computer land management has been introduced.

Nowadays, the majority of the Local Bodies are going to acquire by digital means all the available databases (cartographical and alphanumeric ones), at times without paying much attention to their quality, but facing a big expense of financial resources. Now the more urgent problems to solve are the completing, the validation and the adaption of these databases. Often, these operations are made possible by Field Data Capture (FDC) only.

At present, the updating of territorial information about vast scales is realized nearly everywhere thanks to the work of technicians equipped with paper and pens. Manual Field Data Capture is composed by different operative phases: the preparation in A4 or A3 size of cartographical extracts and informative forms to fill on the spot, the capture of the information, their manual checking, the coming back to the lead office doing the inventory of what has been gathered in order to transfer data into the GIS.

All that means a big waste of time before all, but the other risk consists in making some mistakes and omissions during the moment of the capture, also considering that the operator does not possess the proper data checking/validating instruments. The ”Mobile GIS” stations, composed by a laptop or Pen Computer, a GPS sensor, a Digital Camera (and VideoCamera) and by a software collecting all of them in a GIS environment, give the possibility to abbreviate the proceeding: the moment of the capture itself lasts the same time, but now the operations of data file and post processing diminish drastically in general, thanks to the complete digital system (and to the spatially referentiation of course) that can be executed digitising at source.

The ”Mobile GIS” oriented applications make a large use of personalized forms to fill in, containing logical checks, minimum and maximum value limits to input, possibilities for a guided choice thanks to hot buttons and keywords, the automatic control of the filling of all items, so the amount of errors can be reduced and it is also possible an autovalidation form of inputs.

As far as the instruments are concerned, after having mentioned Digital Camera, which provides satisfying picture resolutions, it is suitable to dwell upon the PC. In our country, the culture of the Digital Field Data Capture has not spread very much; the laptop itself has been used nearly improperly and however its potentialities have not been exploited very much, also because from an operative point of view we can say it represents in a certain sense an hybrid between a desktop and a Pen Computer (!) The latter was born for Field Data Capturing, its weight is about 1200 grams, it is provided with a lithium set of batteries which guarantees a five-hours duration, it supplies a sophisticated advanced power management, an infra-red port for transferring data without cable, an LCD screen with backlight for outdoor works, an external floppy drive and much more. Pen environment is characterized by a series of typical software functions, such as the Operating System ”MS Windows for Pen” and the ”MS Word and Excel for Pen” products, which supply an interface that can improve the performances of the optical pen (these performances are recognized by Pen based Operating Systems and software), diminishing the recurrence to typing and also the conversion of cursive characters (CIC) and inputs by digital keyboard are made possible.

As far as the GPS System is concerned, it should provide the differential correction and guarantee a high level of accuracy which will depend on the kind of gathered information: for example what is required to update a cartographical base (topographical capture) is a great accuracy in order of very few centimeters, whereas to complete it with higher informative levels (environmentals and fiscal captures) what is especially appreciated are data which approximated to reality of some meters. Of course the exact datum is more expensive and so, during the phase of choice, all that will be depending on its relative importance inside the GIS.

The software management station should eventually satisfy the principle of the maximum integration of the peripherals and of gathered data supplying GIS functions by optical pen, such as objects selection, zoom (very useful), creation of spatially referred layers with sketch pads and so on.

Inside of an organization which deals with AM/FM data we can imagine a scenery where the data administrator is in charge to assign to his staff the orders about a work on the spot and to check the Field Data Units according to different operativity levels (read only, access by password, unconditional access).

That is a system based on a client-server architecture with moving client unit, where data transmission can be realized by different ways and costs, according to the level of importance to have up-to-date spatial data in due time or not (we have to think of the sanitary emergencies management or valuables transport, in these cases the radio-modem provides adaptations in due time; there is a large use of queries about data which are distributed to the different moving units, or of queries to the server, then the results are transmitted to the Field Data Units). The traffic between the supervision unit and the FDU is coordinated by a Process Unit which also provides the compression of files to be transferred

The integrated software GIS modules are available, they are used for checking data flows and for operating units on the spot; they supply options for multiple uploading/downloading and for merging operations between data inside the station and the new ones coming from the field.

The ”Mobile GIS” area deals with the capturing and upkeeping of all those territorial elements characterized by a high level of modification in space and time, so that they need frequent checks on the spot. The problems which refer to these aspects contribute to the best utilization of the ”Mobile GIS”.

Among the operative applications, we can remark the capture and the upkeeping of facilities management, breakdown service management, sales management, warehouses stocks with regard to distribution, the compilation and the upkeeping of land registers, the upkeeping of vegetational resources, forestry, fauna, cultivations conditions and the updating of cartographical bases (where ”Mobile GIS” is not replaced by Aerophotogrammetry).

Then, we can remark properly management applications, to which italian reality will be able to approach when the development of the office automation will be pursued: for example concerning insurance premiums management and the market opinions management.

In our country, interventions in the field of civil protection and of advertisement -public billpostings, are quite frequent. In the firsi case, it is important the spatially referring of burning areas, of water supply sources, of the streets conditions to prevent and to upkeep fire emergencies (in Emilia-Romagna, Trentino Alto Adige and Liguria Regions). The ”Mobile GIS” geographical capturing of calamity area is realized by walking down the place and filling in the digital forms (acquired to the System) at the same time; these forms are distributed by the State Foresters (the best result concerning time has been checked out capturing a thirty hectares wide area).

The advertising is controlled by dealer firms facing the constant problem of monitoring road signs, and, on a municipal level, public billpostings.

Thanks to ”Mobile GIS”, the spatially referred file which is complete and updated too, consists of descriptive data and of the digital image of the billposting.

We could also say that ”Mobile GIS” environment represents one of the first standard vertical GIS solutions: part of the merit goes to the firms who have acted in such a direction; for example the Fujitsu solutions (for Pen PC), the Pen Metrics one (for the Mobile GIS software Field Notes, provided with Pen, GPS and Digital Camera interfaces), also Trimble with its integrated proposal ”Direct GPS for Arc View”, in collaboration with ESRI. Some of these subjects have tried to make the procedures to obtain data as easier as possible, reducing the number of supplied functions but trying to minimize the intrusive nature of the machine, that is the primary cause (the character) of the resistances to the use of technological instruments by Field Users. The latter are divided in two parts in USA as well as in Europe: those who fear that automation may steal their job and those who feel anxious to get automated.

At any rate, when a manual Field Data Capture system works rather well, it is essential to create a pilot project to check tangible and brief-term reductions and armonizations of costs caused by the ”Mobile GIS” use; later on we can pursue to obtain the best results from the employed resources (time, money, technicians) and to obtain the maximum benefits of management, trying not to be confused by the new exiting technology.

The digital capturing, apart from the cost of instruments (and their consumable parts) is bound by the project elaboration, it consists of customization costs (verticalization of the system is very important as above said), implementation and training charges. Fixed costs are more than fifty per cent and that does not help the spreading of Mobile GIS technology, which counts, among its benefits, the reduction of the vital cycle of data acquisition process, the mechanism of controlling and autovalidating data, its intuitive use, the penstrokes (that is to say written pen environment symbols, which represent editing functions such as zooming, panning, cutting, copying, pasting and so on..)

The spreading problems with the ”Mobile GIS” technology are connected with the generalized lack of training existing in this Area, as well as with the delay with which the supply approaches to the demand with vertical process solutions; only by the latters (and there are some), the concerned subjects can estimate with a good approximation the convenience of using GIS on moving platforms.