ROMPOS FOR CADASTRE APPLICATIONS

Transcription

1 International Symposium on Global Navigation Satellite Systems, Space-Based and Ground-Based Augmentation Systems and Applications 2009; Berlin, Germany, 30 November - 2 December 2009 ROMPOS FOR CADASTRE APPLICATIONS Tiberiu Rus, Petre Dragomir, Neculai Avramiuc, Paul Dumitru, Mihaela Fădur, Vlad Sorta Abstract: This paper presents aspects concerning the new developments in the field of precise positioning based on GNSS technology with application in cadastre. It is introduced the ROMPOS (Romanian Position Determination System) developed by National Agency for Cadastre and Land Registration (NACLR) Department of Geodesy and Cartography. It is the second GNSS permanent network as number of stations from Central and East Europe, after Polish GNSS permanent network. ROMPOS-GEO postprocessing service it is realized especially for geodetic network modernization and precise positioning (cm...mm level). ROMPOS-RTK and ROMPOS- DGNSS services are dedicated to real time centimeter and decimeter level positioning. Thanks to EUPOS organization the new developed standards were very helpful for the realization of ROMPOS. Cross border GNSS real time data exchange started with similar services from Hungary and Bulgaria. The general cadastre in Romania was not yet implemented and ROMPOS will be one of the main infrastructure realized to support this project. New standards for GNSS-RTK positioning in cadastre applications are introduced by NACLR. There are presented examples of ROMPOS services for cadastre applications. Keywords:: ROMPOS, GNSS, permanent station, RTK, cadastre 1. Introduction Romanian National Network of GNSS Permanent Stations (RN-SGP) includes a number of 58 stations in 2009 and other are planned for 2010 up to 73 stations. RN-SGP started to be realized in 2004 and included a continuous development. Average distance between the stations after completion of permanent GNSS stations RN-GSP (2010) will be around 70 km. Equipments used in RN-SGP are able to receive satellite signals of actual global navigation systems (NAVSTAR-GPS and GLONASS) recording dual frequency measurements (including L2C). Some stations have meteorological sensors recording pressure, temperature and humidity at the prescribed intervals. Since 2006, in addition to permanent IGS (International GNSS Service) and EUREF station BUCU (Bucharest) other four permanent GNSS stations: BACA (Bacău), BAIA (Baia Mare), COST (Constanta), and DEVA (Deva) were included in EUREF-EPN (European Reference Frame European Permanent Network). 2. Romanian Position Determination System - ROMPOS Implementation of modern services to determine the position based on satellite positioning technology using GNSS (Global Navigation Satellite System), the transition from the GNSS position determination in postprocessing, to determine the position in real time requires the development of augmentation positioning systems at regional, national or local level. Augmentation systems provide users with additional information - differential corrections in order to achieve real-time positioning accuracy level on decimeters or centimeters. Depending on the required precision there are realized systems to determine the position by D-GNSS (Differential GNSS) and RTK (Real Time Kinematic). Such a system for position determination it is ROMPOS - Romanian Position Determination System, realized by the National Agency for Cadastre and Land Registration (NACLR). The ROMPOS was launched in Romania in September 2008 and includes the following services: ROMPOS DGNSS - for applications in real-time kinematic positioning with accuracy between 3m and 0.5m; ROMPOS RTK - precise kinematic applications in real time with precision between 0.5 and 2cm;

2 ROMPOS GEO (Geodetic ) postprocessing applications and precision under 2cm. Currently ROMPOS positioning services in real time are offered by National Agency for Cadastre and Land Registration for a wide range of users (about 400 RTK registered users by September 2009). Fig. 1. Romanian National GNSS Permanent Stations Network - 58 stations (2009) The ROMPOS tariffs (free of charge) of the National Agency for Cadastre and Land Registration encourage the use of ROMPOS RTK / DGPS for positioning applications in real time. Fig. 2. Romanian National GNSS Permanent Stations Network - 73 stations (2010)

3 3. ROMPOS for Cadastre Applications Services provided by NACLR through the ROMPOS system, has some advantages in applications in the field of cadastre, compared with conventional measurement techniques: no need for the visibility between the surveyed points, short time of measurement using realtime services (RTK), homogeneous determinations by connecting to the European reference system ETRS89 and homogenous transformation in the projection plan. The need to use modern technology, practically independent of weather conditions, increase productivity and reduce costs. By integrating the ROMPOS system into the Central and East European system - EUPOS, similar services are available allowing a uniform position even when crossing the border with neighbor countries. Currently NACLR is finalizing arrangements for cooperation with similar services from Hungary and Bulgaria after successful testing for few months. As extension ROMPOS it is at present the second GNSS permanent network as number of stations from Central and East Europe, after Polish GNSS permanent network. Ukraine Hungary Moldova Serbia Black Sea Bulgaria Fig.3 ROMPOS and data exchange with similar services from neighbor countries The most important applications of the ROMPOS system for cadastre are: - realization of the densification network; - coordinate determination of points which defines the land parcel limits; - in detail measurements for various cadastral works (forestry, public utilities, water works et al.), including the determination of characteristic points of the parcels. In order to realize the measurement network and to measure the detail points, the users of the ROMPOS positioning services must follow the steps: - realizing the measurement network using static/fast static measurements; connection to hierarchically higher GNSS networks in the area will be made (Class A, B, C); - realizing the detailed measurements using the static/fast static or kinematic measurement methods. The kinematic method can be done by post-processing or real-time method.

4 For kinematic measurements in post-processing mode, at least one reference station (of the user) placed in the working area (recommended) or a permanent reference station from ROMPOS will be used. In case of RTK measurements: reference stations (at least one) placed in the work area and short range (radio) communications; permanent (real) reference stations from ROMPOS and communications (GPRS) to distance the ROMPOS-RTK service (the method with real stations); virtual reference stations (VRS), which were generated based on the data collected from real ROMPOS reference stations the ROMPOS-RTK VRS service (the method with virtual reference stations); Similarly to detail surveying realized with classical technology (electro-optical), the NACLR regulations specifies the fact that these detail determinations by kinematic method will be realized bazed on the principle of redundancy (more measurements than necessary), so that determining the position in RTK mode will include two determinations of coordinates in each point of detail (similarly to the method of double measurement) by realizing two initializations of the observations at short time intervals (seconds, minutes). A3 B2 B3 C C3 R a1 R2 a2 4 R3 3 C1 C4 B1 B4 A1 A2 Fig. 4. GNSS geodetic network scenario for cadastre application (Legend: A (real)reference station Class A ( km); a (virtual)reference station (hundreds of meters); B densification network Class B (approx. 40 km); C densification landmarks Class C (approx. 10 km); R points from the measurement network (hundreds of meters... 1km); 1,2.. detail points to be observed (tens hundreds of meters)) Advantages of using ROMPOS for Cadastre applications The services provided by NACLR through the ROMPOS system includes advantages in comparison with classical measurement techniques: - no need for visibility between the points which will be determined; - shorter measurement times by using the real time services (RTK); - homogenous determinations through connection with the ETRS89 reference system and homogeneous transformation in the projection plan; - necessity to use a modern technology, which is practically independent from the meteorological conditions;

5 - a raise in productivity and a reduction in costs (after an initially higher investment in GNSS technology); - availability of services (24 hours in case of real time ). Fig. 5. Example of using the ROMPOS-RTK service for cadastre applications 4. Conclusions In the actual context of the global technological developments, the modernization of the national geodetic network had a spectacular jump by realizing the ROMPOS system. This system forms the base of the national spatial geodetic network, allowing the integration of the geodetic network into the European and the global one. NACLR has done a serious effort in the last five years for ROMPOS realization. ROMPOS includes at present 58 GNSS permanent stations and 73 stations on the final system in 2010; There are available 3 services according to EUPOS standards; Thanks to the sustained effort of all the persons involved in the project, in September 2008 ROMPOS was launched for a large area of users and applications. Real time services of ROMPOS (DGNSS/RTK) are free of charge. The target applications of the ROMPOS system are those from the domains of geodesy, topography, cartography, aerial mapping, and cadastre. An example of RMOPOSS application for Cadastre was presented. REFERENCES (selected) [1] OGP Surveying and Positioning Guidance Note number 7, part 2 April 2006, Coordinate Conversion and Transformations including Formulas [2] Order nr. 634/2006 of the General Director NACLR - Regulations regarding the content and the mode of realizing the cadastral documents for registration in the land registry [3] Dragomir P., Rus T., Dumitru P. (2005), Integrarea Reţelei Naţionale de Staţii GPS Permanente în Reţeaua Europeană EUPOS (Integration of the National Network of Permanent GPS Networks in the EUPOS European Network), Modern Technologies for the IIIrd Millenium, Oradea, 2005 [4] Dragomir P., Rus T., Dumitru P. (2008), Aspects Regarding the Use of ROMPOS in Cadastre), Modern Technologies for the IIIrd Millenium, Oradea,