Satellite Altimetry
2013 Esri Survey Summit July 6–9, 2013 | San Diego, California
Vertical Crustal Motion in the Northwestern Gulf of Mexico by Integrating Permanent GPS, Tide Gauge and Satellite Altimetry Nijaz Karacic, RPLS - Pacheco Koch Randall L. Marshall, RPLS
Esri UC2013 .
Hello my name is Fred Flintstone and I am here today to discuss GPS theory for surveying in present–day times
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Outline 1. Introduction •
Intro to Vertical Crustal Motion
•
Gulf of Mexico Vertical Crustal Motion
•
How Can We Measure It
•
Geology of the Region
2. Previous Research 3. Available Observations measuring components of VCM •
Satellite Altimetry
•
In Situ Sea Level Data
•
Permanent GPS CORS Data
4. Procedure and Methodology 5. Presentation And Analysis Of Results 6. Discussions and Conclusions 7.References
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Intro to Vertical Crustal Motion Recently, observations of Vertical Crustal Motion (VCM) from improved GPS network solutions and combined tide gauge and satellite altimetry solutions have become available. The determination of VCM at tide-gauge locations relies on two observations: absolute and relative sea level change obtained from satellite altimetry and tide gauge records, respectively. In principle, the difference between the two sea level time series represents VCM. In addition, GPS vertical rates provide a direct measurement of VCM. Mostly subsidence, compaction and consolidation of sediments, together with large-scale tectonic processes, dominate the crustal motion signal. The re-analysis of tide gauge, GPS, and altimetry, with a focus on the Northern Gulf of Mexico coast, is required in order to determine local vertical motion and its changes along the Gulf coast. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Intro to Vertical Crustal Motion
Ostanciaux, 2011
Global Vertical Crustal Motion rates based on difference between records from satellite altimetry and tide gauge records. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Intro to Vertical Crustal Motion (Cont.)
SONEL, URL5
Global Vertical Crustal Motion rates based on GPS Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
How Can We Measure It •
GPS – VCM(Crustal Motion)
•
Satellite Altimetry – VASL(Absolute Sea Level)
•
Tide Gauges – VRSL(Relative Sea Level) (Crustal Motion Included)
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
How Can We Measure It (Cont.)
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Geology of the Region •
Houston-Galveston Area
•
Southern Louisiana Area
•
Mississippi Delta Area Regional map, showing the northwestern Gulf of Mexico. Red dashed lines show the eastward migration of deposit centers. The salt basin extends from the Luling-Mexia-Talco fault zone to the Sigsbee escarpment. (Engelkemeir, 2008)
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Geology of the Region (Cont.) Compaction and consolidation of young (Holocene) sediments. Older sediments also compact, but at lower rates. Organic rich marshy sediments are susceptible to extreme compaction when drained for agriculture or urbanization. As the sediments desiccate, carbon-rich material oxidizes to CO2, diffusing into the atmosphere with consequent mass and volume loss in the soil. Subsidence due to mass loading. If sediment flux is steady, the delta attains a state close to isostatic equilibrium. The Mississippi delta received a large sediment load near the end of Holocene glaciation. The delayed response of the viscous upper mantle means that the delta is still adjusting to this load, possibly causing several millimeters per year of subsidence (Ivins et al., 2007). Clearing the continental interior for agriculture in the past 150 years may also have increased sediment supply and recent loading. Tectonic subsidence. Gravity sliding (downslope movement of a delta due to the gravitational load of the sediments) also contributes to subsidence. For the Mississippi delta, GPS data show approximately 2 ±1 millimeters per year of southward motion toward the Gulf of Mexico (Dokka et al., 2006). Associated subsidence is less precisely known and may vary as a function of distance from active normal faults accommodating the motion. The mean rate of GPS measured delta subsidence (5± 2 millimeters per year (Dokka et al., 2006) represents the sum of several effects, including mass loading and tectonic subsidence. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Previous Research 1. Nerem and Mitchum (2002)
Legend:
2. García et al. (2007)
BLUE=TG & ALT
3. Kuo et al. (2004, 2008)
RED= GPS, TG & ALT
4. Ostanciaux et al. (2011)
WHITE= GPS
5. Ray et al. (2010) 6. Bouin and Wöppelmann (2010) 7. Braun et al. (2007) 8. Santamaría-Gómez et al. (2011) 9. Dokka at al. (2006)
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Previous Research (Cont.) Nerem and Mitchum (2002) evaluated the differences between the absolute and relative sea level change from satellite altimetry and tide gauge records. This earlier study is of course based on a shorter time span (1992–2001) and a shorter database. García et al. (2007) used data from approximately the same period but instead focused on the Mediterranean Sea, where Nerem and Mitchum (2002) did not include any data. Kuo et al. (2004, 2008) combined the regional mean sea level, tide gauge and altimetry data, and long tide gauge records. Ray et al. (2010) released the latest comparison of DORIS data with estimates of VGM rates derived from satellite altimetry and tide gauge records (from 1992 to 2009) for selected data points. Bouin and Wöppelmann (2010) carried out a study of global accuracy on the basis of GPS data in comparison with estimates of VGM rates inferred from tide gauge records and the mean absolute sea level.
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Previous Research (Cont.) Santamaría-Gómez et al. (2011) focuses on the effects of time correlation in weekly GPS position time series on velocity estimates and demonstrated that correlated noise content with homogeneously reprocessed data is dependent on time series length and, especially, on data time period and showed that the data period dependency cannot be explained by the increasing tracking network or the ambiguity fixation rate but is probably related to the amount and quality of recorded data. Braun et al. (2007) compares vertical motion observations with predictions obtained from 70 different GIA models and showed that both sets of independent observations (tide gauges/altimetry and GPS) are highly correlated and showed very similar fit to the models. Ostanciaux et al. (2011) computed VGM rates by combining tide gauges records and local satellite altimetry, compared this database to previous studies that use geodetic techniques and tide gauges records in order to evaluate the consistency of their results and previous ones. Dokka at al. (2006) defined tectonic control of subsidence and southward displacement of southeast Louisiana with respect to stable North America. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations Satellite Altimetry Data
VASL - Absolute Sea Level
Data derived from global satellite measurements obtained from CLS/CNES/Legos Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations (Cont.) In Situ Sea Level Data
VRSL - Relative Sea Level
Historical sea level data derived from coastal tide gauge records obtained from CSIRO. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations (Cont.) Locations of CORS Sites and TGs
Locations of Permanent CORS Sites, Tide Gauges, and the growth faults of the region
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations (Cont.) Satellite Altimetry-Gulf of Mexico
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations (Cont.) Satellite Altimetry-NW Gulf of Mexico
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Procedure and Methodology 1. Data Acquisition •
Permanent GPS CORS Site data obtained from NGS
•
Tide gauges records obtained from TCOON, PSMSL and NOAA
•
Satellite altimetry obtained from AVISO
•
Geological Records obtained from UTD library and online from USGS
2. Data Processing A.GPS •
Software and algorithms developed using a Linux Shell script to automate processing using NGS OPUS Solutions
•
Results of automated processed CORS site sorted to create GPS time series in Matlab
B. Satellite Altimetry •
Use of “Regional MSL Trend from October of 1992 – December of 2012” obtained from AVISO
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Procedure and Methodology (Cont.) C. Tide Gauges •
Completed data processed and latest corrections as seasonal signal applied
3. Validation of VCM with Independent Observations •
Comparison of local sea level rates with regional GoM rates
•
Determine satellite altimetry time series using various numbers of footprints closest to the TG
•
Analyze retrieval accuracy between single and combined mission
•
Data analysis of the provided and processed data
•
Investigate several GIA Model outputs
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Procedure And Methodology (Cont.) 4. Correlation with Geological Records •
Correlation of VCM with geological indicators
•
Derive vertical component of change based on all three sensors
•
Perform analysis of residuals for all three sensors supported by the tectonics of the region
5. Uncertainty assessment •
Demonstrate and confirm synergy of obtained VCM with uncertainty assessment
•
Demonstrate uncertainty assessment for individual sensors
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Presentation And Analysis Of Results CORS Sites-Velocities
Subsidence
Uplift
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Presentation And Analysis Of Results Tide Gauges-Velocities
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Presentation And Analysis Of Results Satellite Altimetry
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Presentation And Analysis Of Results
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Discussions And Conclusions 1.
Summary of Findings a.) Obtained Vertical Crustal Motion (VCM) from improved GPS network solutions and combined tide gauges and satellite altimetry solutions b.) Performed the re-analysis of tide gauge, GPS, and altimetry, with a focus on the Northern GoM coast including defining subsidence in all three areas by processing permanent CORS Sites along the Northwestern Gulf of Mexico c.) Identified areas of significant and/or laterally changing VCM for natural hazard assessment d.) Defined by geological records the laterally varying rates of VCM geological records mostly due to oil, gas or water extractions but also influenced by larger scale tectonic motion e.) Investigated strategies of combining different approaches, using networks, localities, temporal coverage and emphasizing new strategies f.) All localities allowed for the direct estimation of subsidence in the Gulf of Mexico area and enabled the discrimination of locally varying rates
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Special Thanks to: 1.
Dr. Alexander Braun
2.
Jacob Maggard
3.
Scott Shumate
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
References [1] Anderson,2007, [2] AVISO, [3] Ballua et al.,2011, [4] Bird et al.,2005, [5] Bouin et al.,2010, [6] Braun&Fotopoulos,2007, [7] Braun et al.,2008, [8] Cazenave et al.,1999, [9] Cazenave et al.,2003, [10] Cazenave et al., 2008, [11] Church et al.,2010, [12] Church et al.,2011, [13] Dixon et al.,2008, [14] Dokka et al., 2006, [15] Engelkemeir&Khan,2008, [16] Fu,2009, [17] García et al.,2007, [18] Holzer,1987, [19] IPCC,2007, [20] Ivins,2007, [21] Jacob at al.,2012, [22] Kuo et al.,2004, [23] Kuo, et al.,2008, [24] Mazzotti, et al.,2003, [25] Mazzotti et al.,2007, [26] Merrifield et al.,2010, [27] Morton et al.,2002, [28] Nerem&Mitchum,2002, [29] NOAA, [30] Ostanciaux, 2011 [31] Ray et al., 2010, [32] Santamaría-Gómez et al.,2011, [33] Shum et al.,2002, [34] Salvador, 1991, [35] Törnqvist et al.,2008, [36] Williamson,1959, [37] Winker,1982, [38] Wöppelmann et al.,2007, [39] Wöppelmann et al.,2009, [40] Wöppelmann&Marcos,2012
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Discussion/Questions
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Vertical Crustal Motion in the Northwestern Gulf of Mexico by Integrating Permanent GPS, Tide Gauge and Satellite Altimetry Nijaz Karacic, RPLS - Pacheco Koch Randall L. Marshall, RPLS
Esri UC2013 .
Hello my name is Fred Flintstone and I am here today to discuss GPS theory for surveying in present–day times
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Outline 1. Introduction •
Intro to Vertical Crustal Motion
•
Gulf of Mexico Vertical Crustal Motion
•
How Can We Measure It
•
Geology of the Region
2. Previous Research 3. Available Observations measuring components of VCM •
Satellite Altimetry
•
In Situ Sea Level Data
•
Permanent GPS CORS Data
4. Procedure and Methodology 5. Presentation And Analysis Of Results 6. Discussions and Conclusions 7.References
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Intro to Vertical Crustal Motion Recently, observations of Vertical Crustal Motion (VCM) from improved GPS network solutions and combined tide gauge and satellite altimetry solutions have become available. The determination of VCM at tide-gauge locations relies on two observations: absolute and relative sea level change obtained from satellite altimetry and tide gauge records, respectively. In principle, the difference between the two sea level time series represents VCM. In addition, GPS vertical rates provide a direct measurement of VCM. Mostly subsidence, compaction and consolidation of sediments, together with large-scale tectonic processes, dominate the crustal motion signal. The re-analysis of tide gauge, GPS, and altimetry, with a focus on the Northern Gulf of Mexico coast, is required in order to determine local vertical motion and its changes along the Gulf coast. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Intro to Vertical Crustal Motion
Ostanciaux, 2011
Global Vertical Crustal Motion rates based on difference between records from satellite altimetry and tide gauge records. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Intro to Vertical Crustal Motion (Cont.)
SONEL, URL5
Global Vertical Crustal Motion rates based on GPS Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
How Can We Measure It •
GPS – VCM(Crustal Motion)
•
Satellite Altimetry – VASL(Absolute Sea Level)
•
Tide Gauges – VRSL(Relative Sea Level) (Crustal Motion Included)
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
How Can We Measure It (Cont.)
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Geology of the Region •
Houston-Galveston Area
•
Southern Louisiana Area
•
Mississippi Delta Area Regional map, showing the northwestern Gulf of Mexico. Red dashed lines show the eastward migration of deposit centers. The salt basin extends from the Luling-Mexia-Talco fault zone to the Sigsbee escarpment. (Engelkemeir, 2008)
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Geology of the Region (Cont.) Compaction and consolidation of young (Holocene) sediments. Older sediments also compact, but at lower rates. Organic rich marshy sediments are susceptible to extreme compaction when drained for agriculture or urbanization. As the sediments desiccate, carbon-rich material oxidizes to CO2, diffusing into the atmosphere with consequent mass and volume loss in the soil. Subsidence due to mass loading. If sediment flux is steady, the delta attains a state close to isostatic equilibrium. The Mississippi delta received a large sediment load near the end of Holocene glaciation. The delayed response of the viscous upper mantle means that the delta is still adjusting to this load, possibly causing several millimeters per year of subsidence (Ivins et al., 2007). Clearing the continental interior for agriculture in the past 150 years may also have increased sediment supply and recent loading. Tectonic subsidence. Gravity sliding (downslope movement of a delta due to the gravitational load of the sediments) also contributes to subsidence. For the Mississippi delta, GPS data show approximately 2 ±1 millimeters per year of southward motion toward the Gulf of Mexico (Dokka et al., 2006). Associated subsidence is less precisely known and may vary as a function of distance from active normal faults accommodating the motion. The mean rate of GPS measured delta subsidence (5± 2 millimeters per year (Dokka et al., 2006) represents the sum of several effects, including mass loading and tectonic subsidence. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Previous Research 1. Nerem and Mitchum (2002)
Legend:
2. García et al. (2007)
BLUE=TG & ALT
3. Kuo et al. (2004, 2008)
RED= GPS, TG & ALT
4. Ostanciaux et al. (2011)
WHITE= GPS
5. Ray et al. (2010) 6. Bouin and Wöppelmann (2010) 7. Braun et al. (2007) 8. Santamaría-Gómez et al. (2011) 9. Dokka at al. (2006)
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Previous Research (Cont.) Nerem and Mitchum (2002) evaluated the differences between the absolute and relative sea level change from satellite altimetry and tide gauge records. This earlier study is of course based on a shorter time span (1992–2001) and a shorter database. García et al. (2007) used data from approximately the same period but instead focused on the Mediterranean Sea, where Nerem and Mitchum (2002) did not include any data. Kuo et al. (2004, 2008) combined the regional mean sea level, tide gauge and altimetry data, and long tide gauge records. Ray et al. (2010) released the latest comparison of DORIS data with estimates of VGM rates derived from satellite altimetry and tide gauge records (from 1992 to 2009) for selected data points. Bouin and Wöppelmann (2010) carried out a study of global accuracy on the basis of GPS data in comparison with estimates of VGM rates inferred from tide gauge records and the mean absolute sea level.
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Previous Research (Cont.) Santamaría-Gómez et al. (2011) focuses on the effects of time correlation in weekly GPS position time series on velocity estimates and demonstrated that correlated noise content with homogeneously reprocessed data is dependent on time series length and, especially, on data time period and showed that the data period dependency cannot be explained by the increasing tracking network or the ambiguity fixation rate but is probably related to the amount and quality of recorded data. Braun et al. (2007) compares vertical motion observations with predictions obtained from 70 different GIA models and showed that both sets of independent observations (tide gauges/altimetry and GPS) are highly correlated and showed very similar fit to the models. Ostanciaux et al. (2011) computed VGM rates by combining tide gauges records and local satellite altimetry, compared this database to previous studies that use geodetic techniques and tide gauges records in order to evaluate the consistency of their results and previous ones. Dokka at al. (2006) defined tectonic control of subsidence and southward displacement of southeast Louisiana with respect to stable North America. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations Satellite Altimetry Data
VASL - Absolute Sea Level
Data derived from global satellite measurements obtained from CLS/CNES/Legos Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations (Cont.) In Situ Sea Level Data
VRSL - Relative Sea Level
Historical sea level data derived from coastal tide gauge records obtained from CSIRO. Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations (Cont.) Locations of CORS Sites and TGs
Locations of Permanent CORS Sites, Tide Gauges, and the growth faults of the region
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations (Cont.) Satellite Altimetry-Gulf of Mexico
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Available Observations (Cont.) Satellite Altimetry-NW Gulf of Mexico
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Procedure and Methodology 1. Data Acquisition •
Permanent GPS CORS Site data obtained from NGS
•
Tide gauges records obtained from TCOON, PSMSL and NOAA
•
Satellite altimetry obtained from AVISO
•
Geological Records obtained from UTD library and online from USGS
2. Data Processing A.GPS •
Software and algorithms developed using a Linux Shell script to automate processing using NGS OPUS Solutions
•
Results of automated processed CORS site sorted to create GPS time series in Matlab
B. Satellite Altimetry •
Use of “Regional MSL Trend from October of 1992 – December of 2012” obtained from AVISO
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Procedure and Methodology (Cont.) C. Tide Gauges •
Completed data processed and latest corrections as seasonal signal applied
3. Validation of VCM with Independent Observations •
Comparison of local sea level rates with regional GoM rates
•
Determine satellite altimetry time series using various numbers of footprints closest to the TG
•
Analyze retrieval accuracy between single and combined mission
•
Data analysis of the provided and processed data
•
Investigate several GIA Model outputs
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Procedure And Methodology (Cont.) 4. Correlation with Geological Records •
Correlation of VCM with geological indicators
•
Derive vertical component of change based on all three sensors
•
Perform analysis of residuals for all three sensors supported by the tectonics of the region
5. Uncertainty assessment •
Demonstrate and confirm synergy of obtained VCM with uncertainty assessment
•
Demonstrate uncertainty assessment for individual sensors
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Presentation And Analysis Of Results CORS Sites-Velocities
Subsidence
Uplift
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Presentation And Analysis Of Results Tide Gauges-Velocities
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Presentation And Analysis Of Results Satellite Altimetry
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Presentation And Analysis Of Results
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Discussions And Conclusions 1.
Summary of Findings a.) Obtained Vertical Crustal Motion (VCM) from improved GPS network solutions and combined tide gauges and satellite altimetry solutions b.) Performed the re-analysis of tide gauge, GPS, and altimetry, with a focus on the Northern GoM coast including defining subsidence in all three areas by processing permanent CORS Sites along the Northwestern Gulf of Mexico c.) Identified areas of significant and/or laterally changing VCM for natural hazard assessment d.) Defined by geological records the laterally varying rates of VCM geological records mostly due to oil, gas or water extractions but also influenced by larger scale tectonic motion e.) Investigated strategies of combining different approaches, using networks, localities, temporal coverage and emphasizing new strategies f.) All localities allowed for the direct estimation of subsidence in the Gulf of Mexico area and enabled the discrimination of locally varying rates
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Special Thanks to: 1.
Dr. Alexander Braun
2.
Jacob Maggard
3.
Scott Shumate
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
References [1] Anderson,2007, [2] AVISO, [3] Ballua et al.,2011, [4] Bird et al.,2005, [5] Bouin et al.,2010, [6] Braun&Fotopoulos,2007, [7] Braun et al.,2008, [8] Cazenave et al.,1999, [9] Cazenave et al.,2003, [10] Cazenave et al., 2008, [11] Church et al.,2010, [12] Church et al.,2011, [13] Dixon et al.,2008, [14] Dokka et al., 2006, [15] Engelkemeir&Khan,2008, [16] Fu,2009, [17] García et al.,2007, [18] Holzer,1987, [19] IPCC,2007, [20] Ivins,2007, [21] Jacob at al.,2012, [22] Kuo et al.,2004, [23] Kuo, et al.,2008, [24] Mazzotti, et al.,2003, [25] Mazzotti et al.,2007, [26] Merrifield et al.,2010, [27] Morton et al.,2002, [28] Nerem&Mitchum,2002, [29] NOAA, [30] Ostanciaux, 2011 [31] Ray et al., 2010, [32] Santamaría-Gómez et al.,2011, [33] Shum et al.,2002, [34] Salvador, 1991, [35] Törnqvist et al.,2008, [36] Williamson,1959, [37] Winker,1982, [38] Wöppelmann et al.,2007, [39] Wöppelmann et al.,2009, [40] Wöppelmann&Marcos,2012
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
Discussion/Questions
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
