1. Dr. M. Sc. Gintcho Kostov, Bulgaria “GEO ZEMIA” Ltd. Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com

2. 1. Introduction Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com

3. – how the disturber affects a GNSS equipment – the influence of the disturber onto the results from the measurements in RTK mode with the usage of specific settings in the system 2. Aims of the study Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com

4. Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com 3. Conducted Geodetic Measurements. Study and Specifics of the Behaviour of the Rover -the reference GNSS station - set up in close proximity to the area under study; -RTK measurements were conducted inside the disturbed region; -the lengths of the measured spatial chords were less than 1 km.

5. Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com 3. Conducted Geodetic Measurements. Study and Specifics of the Behaviour of the Rover

6. 4. Used Criteria for Assessment of the Overall Quality of the Measured points In this study the following quality criteria were applied: 1. Diagonal elements of the co-variance matrix: Q11, Q22 and Q33; 2. Position quality - Mp; 3. Height quality - Mh; 4. Position and height quality - M3D; Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com

7. point N Q11Q22Q33 Mp [mm] Mh [mm] M3D [mm] rating 3350.000019150.000012310.00009714611120.63 3360.000019160.000012810.00010978611120.63 3500.000019140.000012800.00010994510110.63 3510.000019330.000012820.00011988510110.64 3520.000015830.000012650.00010010510110.64 3530.000019030.000012690.00010491611120.63 3540.000022630.000025740.00029561717180.47 3550.000015600.000012540.00009616510110.64 3700.000019180.000013200.00010867510110.63 3710.000015350.000012680.00010175510120.64 Table 1. Values of the criteria and results for the overall quality assessment 5. Results and Analysis from the Measurements in RTK mode Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com significant difference in the quality

8. 3850.000011550.000010370.00009547612130.66 3900.000015580.000013390.00020323616170.55 3910.000011430.000010360.0000971949100.69 3940.000014430.000011100.00012543613150.63 3950.000011760.000011110.00012155513140.68 3960.000011330.000010360.0001002849100.70 3970.000014390.000011050.0001199549100.65 3980.000011370.000011190.00011799511120.69 3990.000004320.000004080.000043361022240.56 4000.000011350.000010700.00010613511120.69 4010.000011740.000011800.00014581513140.68 4020.000011730.000011290.00013052512130.68 4030.000011960.000011780.00015797512130.68 4040.000011950.000011190.00013835616170.55 4050.000011970.000011700.00015670615160.58 4060.000011850.000011190.00013371615160.58 Table 1. Values of the criteria and results for the overall quality assessment - continued 5. Results and Analysis from the Measurements in RTK mode Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com anomaly - Mp rating low quality variations of the rating highest overall quality extreme low quality point N Q11Q22Q33MpMhM3Drating

9. 4190.000016790.000012750.00012999816180.45 4200.000012450.000010990.00011075613140.65 4210.000012460.000010990.00011050612140.66 4220.000012540.000010990.00010936511120.67 4250.000013080.000011640.00012041817180.47 4260.000013120.000011650.00011957715160.54 4340.000013160.000011020.00009676510110.67 4350.000013310.000011040.0000996159100.67 4360.000013780.000011300.00010815510110.66 4370.000013630.000011070.00010058613140.64 4380.000014150.000012400.00010750612130.64 4390.000014170.000012410.00010731612140.64 4400.000013810.000011260.00010326613140.64 4410.000013830.000011260.00010304613140.64 4420.000013860.000011270.00010265714150.56 4430.000013920.000011290.00010199613140.64 Table 1. Values of the criteria and results for the overall quality assessment - last 5. Results and Analysis from the Measurements in RTK mode Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com variations in the quality low quality equal quality, high rating point NQ11Q22Q33MpMhM3Drating

10. 6. Analysis of the Results According to the calculated results, it could be summarized: 1. variations in the accuracy were ascertained; 2. a degradation of the accuracy up to 24 mm in the open field was observed; 3. M3D quality criterion was not sufficient for complete control of the accuracy – for points NN 397 and 398. More criteria should be considered and used. It must be noted that several years ago in the region under study GNSS measurements could not be conducted due to the strong influence of the active disturber. Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com

11. 7. Conclusions Based on: - continuous improvement of the system; - considering the accuracy results, Geodetic measurements conducted with GNSS equipment nowadays are characterised with better overall quality and reliability in comparison with the passed last years. Taking in mind the quality assessment, the current status of the system and GNSS modernizations it could be concluded: - Currently enough operational satellites exist, which can be used for geodetic determinations and be delivered good quality results in a region with operating active disturber. - The future efforts for GNSS improvements are highly encouraged in order to be obtained: better reliability in the determinations and higher overall quality of the results within places with operating active disturber. Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com

12. REFERENCES: Kostov, G. Assessing of the Overall Quality of GNSS Determinations, Using Specific Values of Parameters. Third International Conference on Cartography and GIS. June, 15-20, Nessebar, Bulgaria, 2010. Minchev, M., Iv. Zdravcev, Iv. Georgiev, Foundations of the application of GPS in geodesy, Sofia UACEG, 2005 (in Bulgarian). Ministry of Regional Development and Public Works. Issued DV issue 79/11.10.2011. Instruction N RD- 02-20-25/20.09.2011 for determination of geodetic points, using GNSS. In effect from 11.10.2011. (in Bulgarian). Tiwari R., Soumi Bhattacharyaa, P.K. Purohitb, and A.K. Gwala. Effect of TEC Variation on GPS Precise Point at Low Latitude. The Open Atmospheric Science Journal, 2009. Tiwari S., Amit Jain, Shivalika Sarkar, Sudhir Jain and A K Gwal. Ionospheric irregularities at Antarctic using GPS measurements. J. Earth Syst. Sci. 121, No. 2, Indian Academy of Sciences, April 2012. Wellenhof, B., Herbert Lichtenegger, James Collins, GPS Theory and practice, Springer-Verlag/Wien, Austria, 2002. (in Bulgarian). Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com

13. WEB: http://en.wikipedia.org/wiki/GLONASS http://en.wikipedia.org/wiki/GPS_modernization http://waas.stanford.edu/~wwu/papers/gps/PDF/IWG/sbas_iono_scintillations_white_paper.pdf http://www.ion.org/search/view_abstract.cfm?jp=p&idno=1292 Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com

14. Study of the Behaviour of the Rover and Assessment of the Overall Quality of the Results from RTK Measurements, Conducted in open-Field - Influenced by Active Disturber www.geozemia.com