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GPS Solutions

, Volume 18, Issue 3, pp 473–481 | Cite as

An open source GPS multipath simulator in Matlab/Octave

  • Felipe G. Nievinski
  • Kristine M. Larson
GPS Toolbox

Abstract

Multipath is detrimental for both GPS positioning and timing applications. However, the benefits of GPS multipath for reflectometry have become increasingly clear for monitoring soil moisture, snow depth, and vegetation growth. In positioning applications, a simulator can support multipath mitigation efforts in terms of, e.g., site selection, antenna design, receiver performance assessment, and in relating different observations to a common parameterization. For reflectometry, in order to convert observed multipath parameters into useable environmental products, it is important to be able to explicitly link the GPS observables to known characteristics of the GPS receiver/antenna and the reflecting environment. Existing GPS multipath software simulators are generally not readily available for the general scientific community to use and/or modify. Here, a simulator has been implemented in Matlab/Octave and is made available as open source code. It can produce signal-to-noise ratio, carrier phase, and code pseudorange observables, based on L1 and L2 carrier frequencies and C/A, P(Y), and L2C modulations. It couples different surface and antenna types with due consideration for polarization and coherence. In addition to offering predefined material types (water, concrete, soil, etc.), it allows certain dimensional properties to be varied, such as soil moisture and snow density.

Keywords

GPS GNSS Multipath Reflectometry Coherent Simulator Simulation 

Notes

Acknowledgments

This research was supported by NSF (EAR 0948957, AGS 0935725). Mr. Nievinski has been supported by a Capes/Fulbright Graduate Student Fellowship (1834/07-0) and a NASA Earth System Science Research Fellowship (NNX11AL50H).

References

  1. Aloi D, van Graas F (1999) Analysis of the effects of Earth-surface based multipath reflections on GPS code-phase measurements. In: Proc ION AM. Institute of Navigation, Cambridge, MA, pp 609–61Google Scholar
  2. Anderson KD (2000) Determination of water level and tides using interferometric observations of GPS signals. J Atmos Ocean Technol 17:1118–1127. doi: 10.1175/1520-0426(2000)017<1118:DOWLAT>2.0.CO;2 CrossRefGoogle Scholar
  3. Auber J-C, Bibaut A, Rigal J-M (1994) Characterization of Multipath on Land and Sea at GPS Frequencies. In: Proc ION GPS. Institute of Navigation, Salt Lake City, UT, USA, pp 1155–1171Google Scholar
  4. Bétaille D (2003) A Testing Methodology for GPS Phase Multipath Mitigation Techniques. In: Proc ION GPS/GNSS. Institute of Navigation, Portland, OR, pp 2151–2162 Google Scholar
  5. Beyerle G, Hocke K (2001) Observation and simulation of direct and reflected GPS signals in radio occultation experiments. Geophys Res Lett 28:1895–1898. doi: 10.1029/2000GL012530 CrossRefGoogle Scholar
  6. Bilich A, Larson KM, Axelrad P (2008) Modeling GPS phase multipath with SNR: case study from the Salar de Uyuni. Boliva. J Geophys Res 113:B04401. doi: 10.1029/2007JB005194 Google Scholar
  7. Boccia L, Amendola G, Gao S, Chen C-C (2013) Quantitative evaluation of multipath rejection capabilities of GNSS antennas. GPS Solut. doi: 10.1007/s10291-013-0321-0 Google Scholar
  8. Boniface K, Aparicio JM, Cardellach E (2011) Meteorological information in GPS-RO reflected signals. Atmos Meas Tech Discuss 4:1199–1231. doi: 10.5194/amtd-4-1199-2011 CrossRefGoogle Scholar
  9. Braasch MS (1996) Multipath effects. In: Parkinson BW, Spilker JJ, Axelrad P, Enge P (eds) Glob. Position. Syst. Theory Appl. AIAA, pp 547–566Google Scholar
  10. Brenner B, Reuter R, Schipper B (1998) GPS landing system multipath evaluation techniques and results. In: Proc ION GPS. Institute of Navigation, Nashville, TN, pp 999–1008Google Scholar
  11. Brodin G, Daly P (1997) GNSS code and carrier tracking in the presence of multipath. Int J Satell Commun 15:25–34. doi: 10.1002/(SICI)1099-1247(199701)15:1<25:AID-SAT565>3.0.CO;2-F CrossRefGoogle Scholar
  12. Byun SH, Hajj GA, Young LE (2002) Development and application of GPS signal multipath simulator. Radio Sci 37:1098. doi: 10.1029/2001RS002549 CrossRefGoogle Scholar
  13. Cardellach E, Fabra F, Rius A, Pettinato S, D’Addio S (2012) Characterization of dry-snow sub-structure using GNSS reflected signals. Remote Sens Environ 124:122–134. doi: 10.1016/j.rse.2012.05.012 CrossRefGoogle Scholar
  14. Chen A, Chabory A, Escher A, Macabiau C (2009) Development of a GPS deterministic multipath simulator for an efficient computation of the positioning errors. In: Proc ION GNSS. Institute of Navigation, Savannah, GA, pp 2378–2390Google Scholar
  15. Chen A, Chabory A, Escher A, Macabiau C (2010) Hybrid deterministic-statistical GPS multipath simulator for airport navigation. In: Bonefačić D, Bosiljevac M (eds) IECom—20th Int. Conf. Appl. Electromagn. Commun, Dubrovnik, Croatia, pp 3–6Google Scholar
  16. Chen C-C, Gao S, Maqsood M (2012a) Antennas for Global Navigation Satellite System Receivers. In: Imbriale WA, Gao S, Boccia L (eds) Space Antenna Handbook. Wiley, pp 548–595Google Scholar
  17. Chen X, Parini CG, Collins B, Yao Y, Ur Rehman M (2012b) Antennas for global navigation satellite systems. Wiley, p 232Google Scholar
  18. Chew CC, Small EE, Larson KM, Zavorotny VU (2013) Effects of Near-Surface Soil Moisture on GPS SNR Data: Development of a Retrieval Algorithm for Soil Moisture. IEEE Trans Geosci Remote Sens 1–7. doi: 10.1109/TGRS.2013.2242332
  19. Cloude S (2009) Polarisation: applications in remote sensing. OxfordGoogle Scholar
  20. Cox DT, Shallberg KW, Manz A (2000) Definition and analysis of WAAS receiver multipath error envelopes. Navigation 46:271–282Google Scholar
  21. Eissfeller B, Winkel JO (1996) GPS Dynamic Multipath Analysis in Urban Areas. In: Proc ION GPS, Institute of Navigation, Kansas City, MO, pp 719–727Google Scholar
  22. Elósegui P, Davis JL, Jaldehag RTK, Johansson JM, Niell AE, Shapiro II (1995) Geodesy using the global positioning system: the effects of signal scattering on estimates of site position. J Geophys Res 100:9921. doi: 10.1029/95JB00868 CrossRefGoogle Scholar
  23. Ercek R, de Doncker P, Grenez F (2005) Study of pseudo-range error due to non-line-of-sight-multipath in urban canyons. In: Proc ION GNSS. Institute of Navigation, Long Beach, CA, pp 1083–1094Google Scholar
  24. Evans J, Capon J, Shnidman D (1989) Multipath modeling for simulating the performance of the microwave landing system. Linc Lab J 2:459–474Google Scholar
  25. Falletti E, Pini M, Lo L Presti (2011) Low complexity carrier-to-noise ratio estimators for GNSS digital receivers. IEEE Trans Aerosp Electron Syst 47:420–437. doi: 10.1109/TAES.2011.5705684 CrossRefGoogle Scholar
  26. Fan K, Ding XL (2006) Estimation of GPS carrier phase multipath signals based on site environment. J Glob Pos Syst 5:22–28. doi: 10.5081/jgps.5.1.22 CrossRefGoogle Scholar
  27. Franchois A, Roelens L (2005) Determination of GPS positioning errors due to multi-path in civil aviation. In: Proc. 2nd Int. Conf. Recent Adv. Space Technol. RAST 2005. pp 400–403Google Scholar
  28. Georgiadou Y, Kleusberg A (1988) On carrier signal multipath effects in relative GPS positioning. Manuscripta Geod 12:172–179Google Scholar
  29. Geren W, Murphy T, Pankaskie T (2008) Analysis of airborne GPS multipath effects using high-fidelity EM models. IEEE Trans Aerosp Electron Syst 44:711–723. doi: 10.1109/TAES.2008.4560216 CrossRefGoogle Scholar
  30. Gomez S, Panneton R, Saunders P, Hwu S, Lu B (1995) GPS multipath modeling and verification using geometrical theory of diffraction. In: Proc ION GPS. Institute of Navigation, Palm Springs, CA, pp 195–204 Google Scholar
  31. Hannah BM, Walker RA, Kubik K (1998) Towards a complete virtual multipath analysis tool. In: Proc ION GPS. Institute of Navigation, Nashville, TN, pp 1055–1063Google Scholar
  32. Irsigler M, Avila-Rodriguez JA, Hein GW (2005) Criteria for GNSS multipath performance assessment. In: Proc ION GNSS. Institute of Navigation, Long Beach, CA, pp 2166–2177 Google Scholar
  33. Italiano A, Principe F (2010) Multipath and interference modelling in complex GNSS scenarios. In: Proc. 4th Eur. Conf. Antennas Propag. EuCAP. pp 1–5Google Scholar
  34. Jacobson MD (2008) Dielectric-covered ground reflectors in GPS multipath reception: theory and measurement. IEEE Geosci Remote Sens Lett 5:396–399. doi: 10.1109/LGRS.2008.917130 CrossRefGoogle Scholar
  35. Kalyanaraman SK, Braasch MS, Kelly JM (2006) Code tracking architecture influence on GPS carrier multipath. IEEE Trans Aerosp Electron Syst 42:548–561. doi: 10.1109/TAES.2006.1642571 CrossRefGoogle Scholar
  36. Kavak A, Vogel WJ, Xu G (1998) Using GPS to measure ground complex permittivity. Electron Lett 34:254–255. doi: 10.1049/el:19980180 CrossRefGoogle Scholar
  37. Kelly J, Cohenour J, DiBenedetto MF, Lamb D (2004) An advanced multipath model for DGPS reference site analysis. In: Proc ION AM. Institute of Navigation, Dayton, OH, pp 315–327Google Scholar
  38. Kernighan BW, Plauger PJ (1982) The elements of programming style, (2nd edn). McGraw-Hill, p 168Google Scholar
  39. King MA, Watson CS (2010) Long GPS coordinate time series: multipath and geometry effects. J Geophys Res. doi: 10.1029/2009JB006543 Google Scholar
  40. Larson KM, Ray RD, Nievinski FG, Freymueller JT (2013) The accidental tide gauge: a GPS reflection case study from kachemak bay Alaska. IEEE Geosci Remote Sens Lett 10(5):1200–1204. doi: 10.1109/LGRS.2012.2236075 CrossRefGoogle Scholar
  41. Lau L, Cross P (2007) Development and testing of a new ray-tracing approach to GNSS carrier-phase multipath modelling. J Geod 81:713–732. doi: 10.1007/s00190-007-0139-z CrossRefGoogle Scholar
  42. Lestarquit L, Nouvel O (2012) Determining and measuring the true impact of C/A code cross-correlation on tracking: application to SBAS georanging. In: Proc IEEE/ION PLANS. IEEE, pp 1134–1140Google Scholar
  43. Lippincott W, Milligan T, Igli D (1996) Method for calculating multipath environment and impact on GPS receiver solution accuracy. In: Proc ION NTM. Institute of Navigation, Santa Monica, CA, pp 707–722Google Scholar
  44. Löfgren JS, Haas R, Scherneck H-G, Bos MS (2011) Three months of local sea level derived from reflected GNSS signals. Radio Sci 46:1–12. doi: 10.1029/2011RS004693 CrossRefGoogle Scholar
  45. Lopez AR (2008) LAAS/GBAS ground reference antenna with enhanced mitigation of ground multipath. In: Proc ION NTM. Institute of Navigation, San Diego, CA, pp 389–393Google Scholar
  46. Luo X, Mayer M, Heck B (2008) Improving the stochastic model of GNSS observations by means of SNR-based weighting. Obs. Our Chang. Earth. Springer, pp 725–734Google Scholar
  47. Macabiau C, Roturier B, Chatre E, Renard A (1999) Airport multipath simulation for siting DGPS reference stations. In: Proc ION NTM. Institute of Navigation, San Diego, CA, pp 135–144Google Scholar
  48. Mironov VL, Fomin SV, Muzalevskiy KV, Sorokin AV, Mikhaylov MI (2012) The use of navigation satellites signals for determination the characteristics of the soil and forest canopy. IEEE IGARSS. pp 7527–7529Google Scholar
  49. Mora-Castro EJ, Carrascosa-Sanz C, Ortega G (1998) Characterisation of the multipath effects on the GPS pseudorange and carrier phase measurements. In: Proc ION GPS. Institute of Navigation, Nashville, TN, pp 1065–1074Google Scholar
  50. Nievinski FG, Larson KM (2014a) Forward modeling of GPS multipath for near-surface reflectometry and positioning applications. GPS Solut 18(2):309–322. doi: 10.1007/s10291-013-0331-y Google Scholar
  51. Nievinski FG, Larson KM (2014b) Inverse modeling of GPS multipath for snow depth estimation—Part I: formulation and simulations. IEEE Trans Geosci Remote Sens. doi: 10.1109/TGRS.2013.2297681 Google Scholar
  52. Ozeki M, Heki K (2011) GPS snow depth meter with geometry-free linear combinations of carrier phases. J Geod 86:209–219. doi: 10.1007/s00190-011-0511-x CrossRefGoogle Scholar
  53. Pinel N, Bourlier C, Saillard J (2010) Degree of roughness of rough layers: extensions of the rayleigh roughness criterion and some applications. Prog Electromagn Res B 19:41–63. doi: 10.2528/PIERB09110907 CrossRefGoogle Scholar
  54. Ray JK, Cannon ME (2001) Synergy between global positioning system code, carrier, and signal-to-noise ratio multipath errors. J Guid Control Dyn 24:54–63. doi: 10.2514/2.4675 CrossRefGoogle Scholar
  55. Rigden GJ, Elliott JR (2006) 3dM: a GPS receiver antenna site evaluation tool. In: Proc ION NTM. Institute of Navigation, Monterey, CA, pp 554–563Google Scholar
  56. Rodgers CE (1992) Multipath simulation software developed for the design of a low multipath DGPS antenna for the US coast guard. In: Proc ION GPS. Institute of Navigation, Albuquerque, NM, pp 43–50Google Scholar
  57. Rodriguez-Alvarez N, Camps A, Vall-llossera M, Bosch-Lluis X, Monerris A, Ramos-Perez I, Valencia E, Marchan-Hernandez JF, Martinez-Fernandez J, Baroncini-Turricchia G, Perez-Gutierrez C, Sanchez N (2011) Land geophysical parameters retrieval using the interference pattern GNSS-R technique. IEEE Trans Geosci Remote Sens 49:71–84. doi: 10.1109/TGRS.2010.2049023 CrossRefGoogle Scholar
  58. Schubert FM, Prieto-Cerdeira R, Robertson P, Fleury BH (2009) SNACS: the satellite navigation radio channel signal simulator. In: Proc ION GNSS. Institute of Navigation, Savannah, GA, pp 1982–1988 Google Scholar
  59. Smyrnaios M, Schn S, Liso M (2013) Multipath propagation, characterization and modeling in GNSS. In: S. Jin (Ed.), Geodetic sciences: observations, modeling and applications, doi: 10.5772/54567, p. 99–124.
  60. Steingass A, Lehner A, Pérez-Fontán F, Kubista E, Arbesser-Rastburg B (2008) Characterization of the aeronautical satellite navigation channel through high-resolution measurement and physical optics simulation. Int J Satell Commun Netw 26:1–30. doi: 10.1002/sat.891 CrossRefGoogle Scholar
  61. Tabatabaeenejad A, Duan X, Moghaddam M (2013) Coherent scattering of electromagnetic waves from two-layer rough surfaces within the Kirchhoff regime. IEEE Trans Geosci Remote Sens 51:3943–3953. doi: 10.1109/TGRS.2012.2229391 CrossRefGoogle Scholar
  62. Treuhaft RN, Lowe ST, Zuffada C, Chao Y (2001) 2-cm GPS altimetry over Crater Lake. Geophys Res Lett 28:4343. doi: 10.1029/2001GL013815 CrossRefGoogle Scholar
  63. van Nee RDJ (1992) Multipath effects on GPS code phase measurements. Navigation 39:177–190Google Scholar
  64. Weiss J, Axelrad P, Anderson S (2007) A GNSS code multipath model for semi-urban, aircraft, and ship environments. Navigation 54:293–307Google Scholar
  65. Woo KT (2000) Optimum semi codeless carrier-phase tracking of L2. Navigation 47:82–99Google Scholar
  66. Zavorotny VU, Larson KM, Braun JJ, Small EE, Gutmann ED, Bilich AL (2010) A physical model for GPS multipath caused by land reflections: toward bare soil moisture retrievals. IEEE J Sel Top Appl Earth Obs Remote Sens 3:100–110. doi: 10.1109/JSTARS.2009.2033608 CrossRefGoogle Scholar
  67. Zhu Z, van Graas F (2009) Earth-surface multipath detection and error modeling for aircraft GPS receivers. Navigation 56:45–56Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Departamento de Cartografia, Faculdade de Ciências e TecnologiaUniversidade Estadual Paulista Júlio de Mesquita FilhoPresidente PrudenteBrazil
  2. 2.Department of Aerospace Engineering SciencesUniversity of ColoradoBoulderUSA

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