Digital Elevation Models for San Juan and Mayagüez, Puerto Rico: 

Procedures, Data Sources and Analysis 

Prepared for the NOAA Pacific Marine Environmental Laboratory (PMEL), Center for Tsunami 

Inundation Mapping Efforts (TIME) by the NOAA National Geophysical Data Center (NGDC) 

May 5, 2006 

Taylor, L.A., B.W. Eakins, R.R. Warnken, K.S. Carignan, G.F. Sharman and P.W. Sloss. 

NOAA, National Geophysical Data Center, Boulder, Colorado 

Corresponding author contact: 

Lisa A. Taylor 

NOAA, National Geophysical Data Center 

Marine Geology and Geophysics Division 

325 Broadway, E/GC 3 

Boulder, Colorado 80305 

Phone: 303-497-6767 

Fax: 303-497-6513 

E-mail: Lisa.A.Taylor@noaa.gov 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 2

CONTENTS

1. Introduction.......................................................................................................................................3 

2. Study Area ........................................................................................................................................3 

3. Methodology.....................................................................................................................................7 

3.1. Data Sources and Processing .....................................................................................................7 

3.1.1. Shoreline.............................................................................................................10

3.1.2. Bathymetry .........................................................................................................12 

3.1.3. Topography ........................................................................................................16 

3.2. Establishing Common Datums ................................................................................................17 

3.2.1. Vertical transformations .....................................................................................18 

3.2.2. Horizontal transformations.................................................................................18 

3.3. Digital Elevation Model Development ....................................................................................18 

3.3.1. Verifying consistency between datasets .............................................................18 

3.3.2. Smoothing of sparse deep-water NOS soundings...............................................18 

3.3.3. Gridding the data with MB-System....................................................................19 

3.4. Quality Assessment of the Grids..............................................................................................19 

3.4.1. Horizontal accuracy............................................................................................19 

3.4.2. Vertical accuracy................................................................................................19 

3.4.3. Slope maps .........................................................................................................19 

4. Summary and Conclusions..............................................................................................................22 

5. Acknowledgments...........................................................................................................................22 

6. References.......................................................................................................................................22 

LIST OF FIGURES

Figure 1a. Shaded-relief image derived from the 3 arc-second Puerto Rico elevation grid........................4 

Figure 1b. Shaded-relief image derived from the 1/3 arc-second Mayagüez, Puerto Rico elevation grid ..5 

Figure 1c. Shaded-relief image derived from the 1/3 arc-second San Juan, Puerto Rico elevation grid.....6 

Figure 2a. Data sources used to compile the 3arc-second Puerto Rico grid................................................8 

Figure 2b. Data sources used to compile the 1/3 arc-second Mayagüez, Puerto Rico grid.........................9 

Figure 2c. Data sources used to compile the 1/3 arc-second San Juan, Puerto Rico grid ........................ 10 

Figure 3. Mangrove and reef coverage around the south west shore of Puerto Rico ............................. 11 

Figure 4. Coastline data sources used in gridding.................................................................................. 12 

Figure 5a. Slope map of the 3 arc-second Puerto Rico grid.................................................................... .20 

Figure 5b. Slope map of the 1/3 arc-second Mayagüez, Puerto Rico grid ................................................20 

Figure 5c. Slope map of the 1/3 arc-second San Juan, Puerto Rico grid...................................................20 

LIST OF TABLES

Table 1a. Specifications for the Puerto Rico grid ......................................................................................7 

Table 1a. Specifications for the Puerto Rico grid ......................................................................................7 

Table 1c. Specifications for the San Juan, Puerto Rico grid......................................................................7 

Table 2. Coastline sources used in gridding...........................................................................................11 

Table 3a. NOS hydrographic survey data: 3 arc-second Puerto Rico grid ..............................................12 

Table 3b. NOS hydrographic survey data: 1/3 arc-second Mayagüez, Puerto Rico grid.........................14 

Table 3c. NOS hydrographic survey data: 1/3 arc-second San Juan, Puerto Rico grid ...........................14 

Table 4. NOS shallow-water multibeam data: 3 arc-second Puerto Rico grid.......................................15 

Table 5. NOS hydrographic survey data: NCCOS bathymetric grid .....................................................15 

Table 6. Bathymetric data sources used in gridding ..............................................................................16 

Table 7. Topographic data sources used in gridding..............................................................................17 

Table 8. Data hierarchy used to assign gridding weight in MB-System ................................................19 

APPENDIX A: VERTICAL DATUM TRANSFORMATION DESCRIPTION................................................................. 23
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 3

Digital Elevation Models for San Juan and Mayagüez, Puerto Rico: 

Procedures, Data Sources and Analysis 

1. INTRODUCTION

The National Geophysical Data Center (NGDC) has developed three bathymetric/topographic digital 

elevation grids of Puerto Rico for the Pacific Marine Environmental Laboratory (PMEL), NOAA Center for 

Tsunami Inundation Mapping Efforts (TIME). These nested elevation grids (grid boundaries shown in Fig. 1) will 

be used as input for the Method of Splitting Tsunami (MOST) Model 

(http://www.pmel.noaa.gov/pubs/PDF/tito1927/tito1927.pdf) developed by PMEL to simulate tsunami generation, 

propagation and inundation. An intermediate 9 arc-second bathymetric grid of the Caribbean previously developed 

by NGDC, will also be used as input to the MOST Model. This report provides a summary of the data sources and 

methodology used in developing a 3 arc-second grid covering the entire island of Puerto Rico and two 1/3 arcsecond grids centered around Mayagüez and San Juan, Puerto Rico. 

2. STUDY AREA

The study area covers the island of Puerto Rico, located in the Caribbean Sea, with special emphasis on the 

coastal communities of San Juan and Mayagüez. Puerto Rico covers 8,959 square kilometers with a population of 

almost 4 million people. The elevation grids that cover this region extend well offshore into deeper water for the 

purpose of tsunami modeling (Fig. 1a, b, c). 

The island of Puerto Rico has three main physiographic regions: mountainous interior, coastal lowlands and 

a karst region. The mountainous interior covers 60% of the island with the highest peak, Cerro La Punta, reaching 

1,338 meters. The coastal lowlands extend 13 to 19 km inward in the north and 3−13 km in the south. The karst 

region, is located in the north of the island. 

The city of Mayagüez is located on the west-central coast of Puerto Rico, covering 197.6 sq km, with a 

population of 104,557 (2000 Census). The Rio Grande de Añasco river lies to the north and the Guanajibo River to 

the south of Mayagüez. Both rivers empty into the Caribbean Sea from the west coast of Puerto Rico. 

San Juan, the capital of Puerto Rico, is located on the northeast coast and has one of the largest harbors in 

the Caribbean. San Juan covers 122 square kilometers with a population of 442,447 (2000 Census). The Bayamón 

River lies west of San Juan and empties into the Atlantic Ocean. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 4

Figure 1a. Shaded-relief image derived from the 3 arc-second Puerto Rico elevation grid. Contour interval: 500 meters.
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 5

Figure 1b. Shaded-relief image derived from the 1/3 arc-second Mayagüez, Puerto Rico elevation grid. Contour interval: 100 meters.
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 6

Figure 1c. Shaded-relief image derived from the 1/3 arc-second San Juan, Puerto Rico elevation grid. Contour interval: 100 meters.
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 7

3. METHODOLOGY

The three elevation grids were developed to meet PMEL required specifications (Table 1), based on input 

requirements for the MOST inundation model. The best available data were obtained by NGDC and used to produce 

the grids. Data processing, grid assembly, and quality assessment are described in the following subsections. 

Table 1a: Specifications for the Puerto Rico grid. 

Grid Area Puerto Rico 

Coverage Area 65° to 68° W; 17° to 19o N 

Coordinate System Geographic decimal degrees 

Horizontal Datum World Geodetic System (WGS84) 

Vertical Datum Mean High Water 

Vertical Units Meters 

Grid Spacing 3 arc-seconds 

Grid Format ASCII raster grid 

Table 1b: Specifications for the Mayagüez, Puerto Rico grid. 

Grid Area Mayagüez, Puerto Rico 

Coverage Area 67.1o to 67.6o W; 17.9o to 18.6o N 

Coordinate System Geographic decimal degrees 

Horizontal Datum World Geodetic System (WGS84) 

Vertical Datum Mean High Water 

Vertical Units Meters 

Grid Spacing 1/3 arc-second 

Grid Format ASCII raster grid 

Table 1c: Specifications for the San Juan, Puerto Rico grid. 

Grid Area San Juan, Puerto Rico 

Coverage Area 65.9° to 66.5o W; 18.35o to 18.8o N 

Coordinate System Geographic decimal degrees 

Horizontal Datum World Geodetic System (WGS84) 

Vertical Datum Mean High Water 

Vertical Units Meters 

Grid Spacing 1/3 arc-second 

Grid Format ASCII raster grid 

3.1 Data Sources and Processing 

Shoreline, bathymetric, topographic, and orthophotographic data (Fig. 2) were obtained from numerous 

federal and state government agencies, universities and private companies, including the U.S. Department of 

Agriculture, the U.S. Geological Survey (USGS), the NOAA National Ocean Service (NOS), and the NOAA 

National Centers for Coastal Ocean Science (NCOOS). Datasets were converted into ESRI shape files and 

transformed to Mean High Water (MHW) vertical datum and WGS84 geographic coordinates. As no V-Datum 

(http://chartmaker.ncd.noaa.gov/csdl/vdatum.htm) model was available for Puerto Rico, vertical datum 

transformations were applied based on tidal model information supplied by PMEL (see Appendix A for details). 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 8

Figure 2a. Data sources used to compile the 3arc-second Puerto Rico grid. Areas covered by the 

high-resolution (1/3 arc-second) grids are identified by hachures. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 9

Figure 2b. Data sources used to compile the 1/3 arc-second Mayagüez, Puerto Rico grid. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 10

Figure 2c. Data sources used to compile the 1/3 arc-second San Juan, Puerto Rico grid. 

3.1.1 Shoreline 

Digital shorelines were obtained from the National Hydrographic Database, the National GeospatialIntelligence Agency, the Puerto Rico Planning Board, the National Oceanic and Atmospheric Administration and 

Dr. Aurelio Mercado at the University of Puerto Rico. The differences between the coastlines are largely qualitative 

and are due mainly to mangrove swamps portrayed as either landward or seaward of the coastline. As areas of dense 

mangrove coverage are known to strongly dissipate tsunami energy, it is important to make the distinction as to 

where the coastline lies relative to these areas. 

1) Digitized coastline of the main island of Puerto Rico obtained from the Puerto Rico Planning 

Board by Dewberry and Davis, Inc. 

This coastline was digitized from 1995 aerial photos as part of the "Centro de Recaudación de 

Ingresos Municipales (CRIM), Land Information System Project" between 1996 and 1998. It was 

degraded from a scale of 1:2,000 to 1:5,000. Dewberry and Davis, Inc. received the coastline in 

multiple pieces by USGS quadrangle which were merged together and checked against orthometric 

photographs for accuracy. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 11

2) Vectorized shoreline of Puerto Rico and the U.S. Virgin Islands derived from NOAA-NOS 

coastal survey maps and aerial photos developed from 1901 - 1995 source data. 

This shoreline dataset represents a vector conversion of NOS shoreline (T-sheets) maps and 

CAD-based Standard Digital Data Exchange Format (SDDEF) data. It was created by the National 

Ocean Service, National Geodetic Survey as part of its ongoing mission to map the coastline of the 

United States. The NOAA NOS, Coastal Services Center developed the procedures used in this project 

and was responsible for project oversight. 

3) NOAA, NOS, OCS extracted vector shoreline.

This coastline was extracted from nautical charts using software developed by the NOAA 

OCS Coast Survey Development Laboratory, Cartographic & Geospatial Technology Program. It is 

referenced to mean high water, NAD83 in non-projected geographic coordinates and based on charts 

with 1:10,000 to 1:80,000 scales. 

Table 2: Coastline data sources used in gridding. 

Source Area Description URL 

Puerto Rico Planning 

Board, Centro de 

Recaudación de Ingresos 

Municipales (CRIM), Land 

Information System Project 

Main island Digitized from aerial photos http://www.crimpr.net/ 

NOAA, NOS Digitized 

coastline Islands Digitized NOAA, NOS 

shoreline maps http://www.csc.noaa.gov/shoreline/data.html

NOAA, NOS, OCS 

Extracted Vector Shoreline Mona 

Island 

Extracted from NOAA nautical 

charts http://nauticalcharts.noaa.gov/csdl/ctp/cm_vs.htm 

After analysis of the available coastlines, the vector shoreline generated from orthometric photos by the 

Puerto Rico Planning Board obtained from Dewberry and Davis, Inc, was chosen for the main island. Surrounding 

islands were added from the NOAA, NOS, OCS Extracted Vector Shoreline and the NOAA, NOS Digitized 

Coastline using ESRI ArcEdit. This compiled coastline (Fig. 3) defines the mangrove-sea interface, encompassing 

mangrove areas around the island, except for the La Parguera area between 66.98o and 67.13o west (Fig.4). 

Figure 3: Coastline sources used in gridding, compiled from: 1) PRPB coastline (blue), 2) NOS Digitized coastline (red) 

and 3) NOAA, NOS, (OCS) Extracted Vector Shoreline (green). 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 12

Figure 4: Mangrove and reef coverage around the south west shore of Puerto Rico. The green box represents the 

Parguera mangrove area which is not encompassed by the PRPB coastline. This area is characterized by an extensive 

development of coral reefs, seagrass beds, and mangrove forests. (Graphic created from ESRI shape files contained on 

NOAA, NOS, NCCOS, Science Biogeography Program CD-ROM: Benthic Habitats of Puerto Rico and the U.S. Virgin 

Islands. Silver Spring, MD: National Oceanic and Atmospheric Administration, 2001.) 

3.1.2 Bathymetry 

Bathymetric datasets used in the compilation of the grids included 96 NOS hydrographic surveys, 3 NOS 

multibeam surveys, US Army Corps of Engineers (USACE) SHOALS LiDAR data, a 5 meter resolution 

bathymetric grid derived from NOS hydrographic survey data and scuba depths off the southwest coast of the island 

of Puerto Rico, deep water multibeam data collected by the USGS north of the island and a 9 arc-second grid 

compiled from Smith and Sandwell predicted-topography data and General Bathymetric Chart of the Oceans 

(GEBCO) bathymetric contours for the southeast portion of the 3 arc-second grid (Fig. 2a). 

1) NOS hydrographic survey data 

A total of 96 NOS hydrographic surveys were used in the grid compilations. The survey data 

were originally vertically referenced to either mean lower low water or mean low water and 

horizontally referenced to Old Puerto Rico datum, Puerto Rico datum and NAD27. Data point spacing 

for the surveys ranges from about 10 meters up to 3 kilometers in deep water. 

Table 3a. NOS hydrographic survey data included in the compilation of the 3 arc-second Puerto Rico grid. 

NOS Survey ID Year of Survey Survey Scale Original Vertical Datum Original Horizontal Datum 

H02468 1904 5,000 MLW Early PR Island Datums 

H02469 1900 10,000 MLW Early PR Island Datums 

H02472 1900 5,000 MLW Early PR Island Datums 

H02490 1909 40,000 MLW Early PR Island Datums 

H02491 1909 10,000 MLW Early PR Island Datums 

H02492 1905 10,000 MLW Early PR Island Datums 

H02536 1901 20,000 MLW Early PR Island Datums 

H02537 1901 20,000 MLW Early PR Island Datums 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 13

H02555 1902 10,000 MLW Early PR Island Datums 

H02582 1905 20,000 MLW Early PR Island Datums 

H02584 1902 20,000 MLW Early PR Island Datums 

H02585 1902 10,000 MLW Early PR Island Datums 

H02633 1903 20,000 MLW Early PR Island Datums 

H02634 1903 20,000 MLW Early PR Island Datums 

H02640 1903 40,000 MLW Early PR Island Datums 

H02672 1904 40,000 MLW Early PR Island Datums 

H02673 1904 20,000 MLW Early PR Island Datums 

H02674 1904 20,000 MLW Early PR Island Datums 

H02676 1909 60,000 MLW Early PR Island Datums 

H02677 1904 20,000 MLW Early PR Island Datums 

H02678 1904 20,000 MLW Early PR Island Datums 

H02686 1904 10,000 MLW Early PR Island Datums 

H02690 1904 10,000 MLW Early PR Island Datums 

H02803 1906 40,000 MLW Early PR Island Datums 

H02804 1906 20,000 MLW Early PR Island Datums 

H02871 1907 20,000 MLW Early PR Island Datums 

H02876 1909 20,000 MLW Early PR Island Datums 

H02877 1909 20,000 MLW Early PR Island Datums 

H02883 1907 20,000 MLW Early PR Island Datums 

H02934 1908 20,000 MLW Early PR Island Datums 

H02935 1908 20,000 MLW Early PR Island Datums 

H02936 1908 20,000 MLW Early PR Island Datums 

H02937 1908 20,000 MLW Early PR Island Datums 

H02938 1908 20,000 MLW Early PR Island Datums 

H03004 1909 20,000 MLW Early PR Island Datums 

H04205 1921 20,000 MLW Early PR Island Datums 

H04725 1927 10,000 MLW Early PR Island Datums 

H04742 1927 10,000 MLW Early PR Island Datums 

H06556 1940 10,000 MLW Early PR Island Datums 

H08637 1962 10,000 MLW Puerto Rico Datum 

H08638 1962 10,000 MLW Puerto Rico Datum 

H08639 1969 5,000 MLW Early PR Island Datums 

H08780 1967 20,000 MLW Early PR Island Datums 

H08811 1964 10,000 MLW Puerto Rico Datum 

H08812 1967 20,000 MLW Puerto Rico Datum 

H08813 1964 5,000 MLW Puerto Rico Datum 

H08814 1964/65 10,000 MLW Early PR Island Datums 

H08848 1965 5,000 MLW Puerto Rico Datum 

H08849 1965 5,000 MLW Puerto Rico Datum 

H08862 1965 5,000 MLW Early PR Island Datums 

H08880 1966 20,000 MLW Early PR Island Datums 

H08985 1968/69 10,000 MLW Early PR Island Datums 

H08988 1968 10,000 MLW Puerto Rico Datum 

H09031 1969 5,000 MLW Puerto Rico Datum 

H09032 1969 5,000 MLW Early PR Island Datums 

H09034 1969 20,000 MLW Early PR Island Datums 

H09110 1970 5,000 MLW Early PR Island Datums 

H09135 1970/71 10,000 MLW Early PR Island Datums 

H09186 1971 10,000 MLW Early PR Island Datums 

H09190 1971 10,000 MLW Early PR Island Datums 

H09264 1972 10,000 MLW Early PR Island Datums 

H09265 1972 10,000 MLW Early PR Island Datums 

H09266 1972 20,000 MLW Early PR Island Datums 

H09267 1972/75 10,000 MLW Early PR Island Datums 

H09270 1967 40,000 MLW NAD27 

H09278 1972 100,000 MLW Early PR Island Datums 

H09463 1975 125,000 MLW Early PR Island Datums 

H09485 1975 10,000 MLW Early PR Island Datums 

H09486 1975 20,000 MLW Early PR Island Datums 

H09490 1975 5,000 MLW Early PR Island Datums 

H09491 1975 5,000 MLW Early PR Island Datums 

H09517 1975 20,000 MLW Early PR Island Datums 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 14

H09587 1976 125,000 MLW Early PR Island Datums 

H09595 1976 100,000 MLW Early PR Island Datums 

H09596 1976 10,000 MLW Early PR Island Datums 

H09597 1976 10,000 MLW Early PR Island Datums 

H09601 1976 10,000 MLW Early PR Island Datums 

H09602 1976 10,000 MLW Early PR Island Datums 

H09603 1976 10,000 MLW Early PR Island Datums 

H09604 1976 20,000 MLW Early PR Island Datums 

H09605 1976 20,000 MLW Early PR Island Datums 

H09607 1976 10,000 MLW Early PR Island Datums 

H09608 1976 10,000 MLW Early PR Island Datums 

H09609 1976 5,000 MLW Early PR Island Datums 

H09610 1976 20,000 MLW Early PR Island Datums 

H09616 1976 10,000 MLW Early PR Island Datums 

H09617 1976 10,000 MLW Early PR Island Datums 

H09618 1976 20,000 MLW Early PR Island Datums 

H09992 1982 80,000 MLW Early PR Island Datums 

H09993 1982 80,000 MLW Early PR Island Datums 

H10073 1983 10,000 MLLW Puerto Rico Datum 

H10074 1983 80,000 MLLW Puerto Rico Datum 

H10076 1983 80,000 MLLW Puerto Rico Datum 

H10077 1983 10,000 MLLW Puerto Rico Datum 

H10078 1983 20,000 MLLW NAD27 

H10083 1983 80,000 MLLW Puerto Rico Datum 

Table 3b. NOS hydrographic survey data included in the compilation of the 1/3 arc-second Mayagüez, Puerto Rico grid. 

NOS Survey ID Year of Survey Survey Scale Original Vertical Datum Original Horizontal Datum 

H02536 1901 20,000 MLW Early PR Island Datums 

H02537 1901 20,000 MLW Early PR Island Datums 

H02555 1902 10,000 MLW Early PR Island Datums 

H02633 1903 20,000 MLW Early PR Island Datums 

H02640 1903 40,000 MLW Early PR Island Datums 

H02676 1909 60,000 MLW Early PR Island Datums 

H02678 1904 20,000 MLW Early PR Island Datums 

H02686 1904 10,000 MLW Early PR Island Datums 

H02690 1904 10,000 MLW Early PR Island Datums 

H02937 1908 20,000 MLW Early PR Island Datums 

H02938 1908 20,000 MLW Early PR Island Datums 

H08985 1968/69 10,000 MLW Early PR Island Datums 

H08988 1968 10,000 MLW Puerto Rico Datum 

H09463 1975 125,000 MLW Early PR Island Datums 

Table 3c. NOS hydrographic survey data included in the compilation of the 1/3 arc-second San Juan, Puerto Rico grid. 

NOS Survey ID Year of Survey Survey Scale Original Vertical Datum Original Horizontal Datum 

H02677 1904 20,000 MLW Early PR Island Datums 

H02876 1909 20,000 MLW Early PR Island Datums 

H02883 1907 20,000 MLW Early PR Island Datums 

H02934 1908 20,000 MLW Early PR Island Datums 

H02935 1908 20,000 MLW Early PR Island Datums 

H04205 1921 20,000 MLW Early PR Island Datums 

H06556 1940 10,000 MLW Early PR Island Datums 

H08848 1965 5,000 MLW Puerto Rico Datum 

H08849 1965 5,000 MLW Puerto Rico Datum 

H10073 1983 10,000 MLLW Puerto Rico Datum 

H10076 1983 80,000 MLLW Puerto Rico Datum 

H10077 1983 10,000 MLLW Puerto Rico Datum 

H10078 1983 20,000 MLLW NAD27 

H10083 1983 80,000 MLLW Puerto Rico Datum 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 15

2) NOS shallow water multibeam 

Three shallow-water multibeam surveys along the southern coast of the island of Puerto Rico 

were conducted by NOS in 2001, and were included in the 3 arc-second Puerto Rico grid. The 

multibeam data were originally vertically referenced to mean lower low water and horizontally 

referenced to NAD83. 

Table 4. NOS shallow water multibeam data included in the compilation of the 3 arc-second Puerto Rico grid. 

NOS Survey ID Year of Survey Survey Scale Original Vertical Datum Original Horizontal 

Datum 

H11033 2001 5,000 MLLW NAD83 

H11034 2001 5,000 MLLW NAD83 

H11036 2001 5,000 MLLW NAD83 

3) NOAA NOS National Centers for Coastal Ocean Science (NCCOS) gridded data 

NOAA’s National Ocean Service (NOS), National Centers for Coastal Ocean Science 

(NCCOS), Center for Coastal Ocean Science (CCOS), Biogeography Team provided a 5 meter 

bathymetric grid generated from NOS hydrographic survey data and depths collected by Biogeography 

Team SCUBA divers. SCUBA depths were used to fill gaps inshore of the NOS survey data. The grid 

was generated using a triangulated interpolated network (TIN) with ESRI ArcView® 3D Analyst 

software. All reef crests were given a depth of 0.3 meters. Model validation using an independent set 

of bathymetric data revealed an average error of less than 0.3 meters. TIN models were then converted 

into raster maps (spatial resolution = 5 x 5 m). After conversion of this grid to MHW and WGS84, 

depth values were compared to NOS hydrographic survey and SHOALS LiDAR data in the same area 

and were within ~ 0.5 meters in most areas. 

Table 5. NOS hydrographic survey data included in the compilation of the NCCOS bathymetric grid. 

NOS Survey ID Year of Survey Survey Scale Original Vertical Datum Original Horizontal Datum 

H02676 1909 60,000 MLW Early PR Island Datums 

H08984 1968 10,000 MLW Early PR Island Datums 

H08985 1968/69 10,000 MLW Early PR Island Datums 

H08986 1968 10,000 MLW Early PR Island Datums 

H08987 1968 10,000 MLW Early PR Island Datums 

H08988 1968 10,000 MLW Puerto Rico Datum 

H08989 1968 20,000 MLW Early PR Island Datums 

H09029 1969 100,000 MLW Early PR Island Datums 

H09033 1969 20,000 MLW Early PR Island Datums 

H09119 1970 10,000 MLW Early PR Island Datums 

H09120 1970 5,000 MLW Early PR Island Datums 

H09183 1971 10,000 MLW Early PR Island Datums 

4) SHOALS LiDAR data 

Bathymetric SHOALS LiDAR data were obtained from Dr. Aurelio Mercado-Irizarry at the 

University of Puerto Rico. The data were originally collected by the USACE from the shoreline to 1 

km offshore at 5 meter spacing. The data were positioned using post-processed kinematic GPS and 

National Geodetic Survey monumentation.
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 16

5) USGS multibeam data 

A 2002 USGS multibeam survey conducted by the NOAA ship Ron Brown over the Puerto 

Rico Trench was available from the NGDC multibeam Arc IMS interactive map 

(http://www.ngdc.noaa.gov/mgg/bathymetry/multibeam.html). The data were collected with a 

SeaBeam 2112 hull-mounted multibeam sonar system and incorporated into the 3 arc-second Puerto 

Rico and 1/3 arc-second San Juan grids. 

6) Intermediate 9 arc-second grid 

No detailed datasets were available for the southeast corner of the 3 arc-second Puerto Rico 

grid. Thus, depth values were extracted from the intermediate 9 arc-second grid, which was compiled 

from Smith and Sandwell predicted topography and GEBCO contours. 

Table 6. Bathymetric data sources used in gridding. 

Source Year Data Type Spatial Resolution Original Horizontal 

Datum 

Original 

Vertical 

Datum 

URL 

NOS 1900 to 

1983 

Hydrographic 

survey data 

Ranges from 10 meters to 3 

kilometers (Varies with scale 

of survey, depth, traffic and 

probability of obstructions) 

Early Puerto Rico 

Island Datum, Puerto 

Rico Datum, NAD27 

MLW, 

MLLW 

http://www.ngdc.noaa

.gov/mgg/bathymetry/

hydro.html 

NOS 2001 Shallow-water 

multibeam 

100% NAD83 MLLW http://www.ngdc.noaa

.gov/mgg/bathymetry/

hydro.html 

NCCOS 

(Ada 

Otter) 

2004 Grid of NOS 

hydrographic 

surveys and scuba 

depths 

10 meter WGS84 MLLW http://coastalscience.n

oaa.gov/ 

University 

of Puerto 

Rico (Dr. 

Aurelio 

Mercado) 

 USACE SHOALS 

bathymetric 

LiDAR data 

5 meter posting NAD83 US Virgin 

Islands, Puerto Rico 

State Plane 

MLLW http://shoals.sam. 

usace.army.mil/ 

USGS (Uri 

ten Brink) 

2002, 

2003 

Deep-water 

multibeam survey 

data 

100% UTM, Zone 19 Ellipsoid http://www.ngdc.noaa

.gov/mgg/bathymetry/

multibeam.html 

NGDC 2005 Grid of Smith and 

Sandwell 

Predicted 

Topography 

combined with 

GEBCO contours. 

9 arc-second WGS84 MSL http://topex.ucsd.edu/

marine_topo/ and 

http://www.bodc.ac.u

k/projects/internation

al/gebco/gebco_digita

l_atlas/gda_developm

ent/ 

3.1.3 Topography 

Topographic datasets used in the elevation grids consist of LiDAR collected at 15 meter postings by the 

USACE obtained from the USDA, National Resources Conservation Service for the main island, USGS National 

Elevation Dataset (NED) 1 arc-second gridded data for Mona, Desecheo and the eastern half of Vieques Islands and 

10 meter gridded topography compiled from photometrically derived elevations by the Puerto Rico Office of 

Management and Budget for small coastal areas of the islands plus Culebra and the western half of Vieques. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 17

1) USACE topographic LiDAR data. 

These topographic LiDAR data were collected by 3001, Inc. for the USACE in 2004 as part of an 

effort to develop digital orthophoto imagery for administration of the US Department of Agriculture GIS 

Orthophotography update program. These data cover nearly the entire island of Puerto Rico at 15 meter 

postings. It was processed to bare earth and referenced to the ellipsoid, with a vertical accuracy of 30 cm 

RMSE. 

2) USGS National Elevation Dataset (NED) 

The USGS National Elevation Dataset (NED) 1 second DEM data were used for the islands of 

Desecheo, Mona, St. Thomas, and the east half of Vieques. The bare-earth elevations obtained were 

referenced to NAD83 and NAVD88 and have a vertical accuracy of +/- 7 to 15 meters depending on source 

data resolution. See the USGS Seamless web site for specific source information 

(http://seamless.usgs.gov/). The dataset was derived from USGS quad maps and aerial photos based on 

surveys conducted in the 1970s and 1980s. 

3) Puerto Rico Office of Management and Budget photometrically-derived elevations 

A Digital Elevation Model (DEM) representation of altitudes over USGS Quadrangles in Puerto 

Rico, with a fixed spatial cell size of 10 by 10 meters, was obtained from the Puerto Rico Office of 

Mangement and Budget (PROMB). The Centro de Recaudación de Ingresos Municipales (CRIM) Basemap 

Project provided the original linework, elevation points and breaklines to the PROMB. The PROMB 

derived the DEMs from TINs previously generated from elevation mass points and 3-D features such as 

hydrography, and breaklines at a scale of 1:2,000. This dataset was used for Culebra Island, the western 

half of Vieques, and to fill gaps within the USACE LiDAR data on the island of Puerto Rico and small, 

near-coastal islands. The CRIM data meet National Mapping Standards for scales 1:2,000.

Table 7. Topographic data sources used in gridding. 

Source Year Data Type Spatial 

Resolution 

Original 

Horizontal 

Datum 

Original 

Vertical 

Datum 

URL for more info 

USDA/USACE 2003 Topographic 

LiDAR 

15 meter posting UTM, Zone 

19 

Ellipsoid http://www.nrcs.usda.gov/programs/ 

USGS various National 

Elevation Dataset 

(NED) 

1 arc-second WGS84 NAVD88 

(MSL) 

http://seamless.usgs.gov/ 

Puerto Rico 

Office of 

Management 

and Budget, 

Centro de 

Recaudación de 

Ingresos 

Municipales 

(CRIM) 

Basemap Project

1996-

1998 

Photometrically 

derived elevations 

10 meter gird NAD83 

HARN US 

Virgin 

Islands, 

Puerto Rico 

State Plane 

NAVD88 

(MSL) 

http://www.crimpr.net/ 

3.2 Establishing Common Datums 

3.2.1 Vertical datum transformations 

Generating a consistent solid-earth surface model is the ultimate goal of this project. Acquired input data to 

the model were originally referenced to a number of different vertical datums. As the three grids developed for 

Puerto Rico are primarily designed for tsunami inundation modeling, a common Mean High Water (MHW) vertical 

reference frame was chosen. Transformation of the various datasets to this reference frame required careful 

determination of the offsets between the original vertical datums and the MHW datum for Puerto Rico. See 

Appendix A for full details on establishing the relationships and transformational equations between these datums. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 18

3.2.2 Horizontal datum transformations. 

Datasets used to compile the grids were originally horizontally referenced to NAD83, NAD27, Puerto Rico 

and Virgin Islands State Plane, Early Puerto Rico Island Datum, Puerto Rico Datum, UTM Zone 19 and WGS84. 

NOS survey data was converted to WGS84 using GEODAS (NADCON); the relationships and transformational 

equations between these horizontal datums are well established. All other data, except that referenced to 

NAD83⎯the difference between NAD83 and WGS84 is negligible⎯were converted to a horizontal datum of 

WGS84 using FME software (http://www.safe.com). FME is an integrated collection of spatial extract, transform, 

and load tools for data transformation and data translation.

3.3 Digital Elevation Model Development 

3.3.1 Verifying consistency between datasets. 

After horizontal and vertical transformations were applied, ESRI shape files were generated for each data 

file, and value consistency between datasets was checked in ESRI ArcMap. Problems and errors were identified and 

resolved before proceeding with subsequent gridding steps. Problems included: 

• National Elevation Data (NED) obtained for the islands of Mona, Monito and Desecheo were offset 

horizontally (up to 100 meters) relative to the digital coastline and surrounding NOS survey data. The NED 

data were manually shifted to fit the digital coastline. 

• Vertical units for the ArcGIS raster grid of NOS survey data/NCCOS dive soundings were determined to 

be feet instead of meters. The grid was converted to meters. 

• A few bad soundings were discovered in the NOS survey data (positive values rather than the proper 

negative ones) and were corrected. 

• Several bad sonar pings were identified in the USGS multibeam data north of the island of Puerto Rico. 

These pings were excised from the data prior to gridding, using the MB-System tool ‘mbedit’. 

• Rectangular gaps within the USACE LiDAR data were identified at 18o17′ N, 66o30′ W and 18o05′ N, 

65o50′ W. CRIM photometric data were used to fill these gaps. 

• The margins of each CRIM photometric data tile were filled with “zero” values that had to removed. 

• All of the topographic datasets (LiDAR, NED and CRIM photometric) contained anomalous values over 

water. In each case, these datasets were clipped to the combined digital coastline so as to preserve negative 

elevation values in the coastal interior areas. 

• A 2005 multibeam survey of the Muertos Trough south of the island of Puerto Rico was conducted jointly 

between the USGS and various Spanish, Puerto Rican, Dominican Republic and British Virgin Islands 

universities and institutions aboard the Spanish research vessel Hespérides (Carbo, et al., 2005). This data 

was originally referenced to the Ellipsoid and UTM Zone 19. After adjusting the values to the geoid and 

then to MHW (see Appendix A), the resulting depths were between 10 and 40 meters shallower than 

multibeam depths from the 2004 USGS Puerto Rico Trench multibeam data. Because of this depth value 

discrepancy, the data were not used in the compilation of the grids. The NOAA ship Ron Brown is 

currently conducting multibeam surveys in the same area, which will result in an independent check of 

depth values in areas where the surveys overlap. After the vertical reference issue is resolved, this Muertos 

Trough multibeam data could be added to the 3 arc-second Puerto Rico and 1/3 arc-second Mayagüez 

grids. 

The quality-assessed ESRI shape files were subsequently converted to xyz files in preparation for gridding.

3.3.2 Smoothing of sparse deep-water NOS soundings. 

In deep water, the NOS survey data had point spacings of up to ~3 kilometers. In order to reduce the effect 

of artifacts in the form of lines of “pimples” in the grid due to this low resolution dataset, a surface was generated 

from these data using ESRI ArcGIS. The surface was then sub-sampled to 10 arc-seconds and exported as an xyz 

file. The original soundings were checked against the processed values to ensure sounding value accuracy. NOS 

hydrographic survey data in each high-resolution grid were surfaced to 1 arc-second. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 19

3.3.3 Gridding the data with MB-System. 

All processed xyz files were gridded using MB-System (http://www.ldeo.columbia.edu/res/pi/MBSystem/). MB-System is an NSF-funded share-ware software application specifically designed to manipulate 

submarine multibeam sonar data, though it can utilize a wide variety of diverse datasets, including generic xyz data. 

The MB-System tool ‘mbgrid’ was used to create each grid—a modeled surface draping the point data—of weighted 

sounding and elevation point data. The data hierarchy used in the ‘mbgrid’ gridding algorithm as relative gridding 

weights is listed in Table 8. Greatest weight was given to the Puerto Rico coastline dataset to preserve the 

submarine–subaerial transition zone. Least weight was given to values extracted from the Intermediate 9 arc-second 

grid, which was used in the 3 arc-second Puerto Rico grid where no other data existed. 

Table 8. Data hierarchy used to assign gridding weight in MB-System. 

Dataset Relative Gridding Weight 

Digitized coastline 500 

USDA/USACE topographic LiDAR 50 

PROMB (CRIM) photometrically-derived topography 10 

SHOALS bathymetric LiDAR 10 

Multibeam bathymetry 10 

USGS NED topography 1 

NOS hydrographic survey data 1 

NCCOS bathymetric grid 1 

Intermediate 9 arc-second grid values 0.1 

3.4 Quality Assessment of the Grids. 

The 3 arc-second Puerto Rico and 1/3 arc-second San Juan grids were compared with the San Juan Bench 

Mark (Appendix A) to check for accuracy. Values extracted from each of these grids at the location of the 

benchmark were 0.76 and 0.13 meters, respectively: actual value of the benchmark is 1.169 meters above MHW. 

The various techniques that can be used to create a representative surface over the individual elevation points result 

in grid elevations for the benchmark site below that of its actual elevation. This is due to predominance of submarine 

values immediately offshore the benchmark; the benchmark lies at the southernmost spit of land jutting southward 

into the San Juan harbor (Fig. 5c). 

3.4.1. Horizontal accuracy 

The elevation grids have an estimated horizontal accuracy 5 meters for topographic features. Bathymetric 

features are resolved only to within a few hundred meters in most deep water areas; shallow, near-coastal regions 

have an accuracy approaching the subaerial topographic features. Positional accuracy is limited by transformation of 

multiple datasets from various datums, and by potentially large positional accuracy of pre-satellite navigated (GPS) 

hydrographic surveys. 

3.4.2 Vertical accuracy 

The grids have an estimated vertical accuracy of 0.1 to 1 meters for topographic areas and 0.1 meters to 5% 

of water depth for bathymetric areas. Topographic values are largely derived from USACE LiDAR surveys, which 

have an estimated vertical accuracy of 0.1 to 0.15 meters. The one arc-second NED data have a vertical accuracy of 

~1 meter. Bathymetric values were derived from the wide range of input data sounding measurements from the early 

20th century to recent, GPS-navigated multibeam sonar surveys and SHOALS LiDAR near-shore surveys. Gridding 

interpolation to determine values between sparse, poorly-located NOS soundings degrades the vertical accuracy of 

elevations in deep-water. 

3.4.3 Slope maps 

A slope map was generated from each ArcGIS grid to inspect for artificial slopes along boundaries between 

datasets (Fig 5a, b, c). The grids were transformed to UTM Zone 19 coordinates (horizontal units in meters) in 

ArcGIS before derivation of the slope grids. Flat-lying slopes appear as white; dark shading denotes steep slopes. 

The shelf break is clearly identified in the slope maps at ~100 meters water depth. Analysis of the slope maps 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 20

revealed suspect data points, which were corrected before re-gridding the data. Known limitations in the grids are 

also apparent from these maps. The boundary between 9 arc-second gridded data and NOS hydrographic survey data 

in the south east area of the 3 arc-second grid (Figure 5a) shows artifact slopes due to differences in data spacings 

and grid resolution. Large ship-track spacing in the generally north-south, east-west NOS hydrographic survey data 

is shown as anomalous striations along tracks in all three grids. 

Figure5a. Slope map of the 3 arc-second Puerto Rico grid with coastline in red. Flat-lying slopes 

are white; dark shading denotes steep slopes. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 21

Figure 5b. Slope map of the 1/3 arc-second Mayagüez, Puerto Rico grid with coastline in red. Flatlying slopes are white; dark shading denotes steep slopes. 

Figure 5c. Slope map of the 1/3 arc-second San Juan, Puerto Rico grid with coastline in red. Flatlying slopes are white; dark shading denotes steep slopes. Triangle locates San Juan benchmark. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 22

4. SUMMARY AND CONCLUSIONS

Three topographic/bathymetric digital elevation grids were built for the Pacific Marine Environmental 

Laboratory (PMEL), NOAA Center for Tsunami Inundation Mapping Efforts (TIME), a 3 arc-second grid covering 

the whole island of Puerto Rico and two 1/3 arc-second grids centered around Mayagüez and San Juan, Puerto Rico. 

The best available data from US federal and state agencies and the University of Puerto Rico were obtained for grid 

compilation. The data were quality checked, processed and gridded using ESRI ArcGIS, FME, GMT and MBSystem software. 

Recommendations to improve the DEM based on NGDC’s research and analysis are listed below: 

 

• New bathymetric LiDAR data being collected along the west and southwest shores of Puerto Rico in 2006 

by the NOAA Office of Coast Survey should be added to the DEMs when available. 

• New multibeam data being collected by the NOAA ship, Nancy Foster along the west and southwest shores 

of Puerto Rico at time of writing for the NOAA Center for Coastal Monitoring and Assessment, 

Biogeography Program should be added to the DEMs when available. 

• Include 2005 multibeam survey of Muertos Trough (Carbó et al, 2005) after vertical reference issue is 

resolved (See Section 3.3.1). 

5. ACKNOWLEDGMENTS

The creation of these grids was funded by the NOAA, Pacific Marine Environmental Laboratory. The 

authors thank Chris Chamberlin, Angie Venturato, and Hal Mofjeld (PMEL), Aurelio Mercado Irizarry (University 

of Puerto Rico), Uri ten Brink (USGS, Woods, Hole), Tim Blak (Dewberry and Davis, Inc.), Tony Kimmet and 

George Rohaley (USDA, National Resources Conservation Service), Ada Otter and Tim Battista (NOAA, NOS, 

National Centers for Coastal Ocean Science), and Ivan Santiago (Puerto Rico Office of Planning and Budget). 

6. REFERENCES

Carbó, A., D. Córdoba, J. Martin Davila, U. ten Brink, P. Herranz, C. Von Hilldebrandt, J. Payero, A. Muñoz 

Martín, A. Pazos, M. Catalán, J.L. Granja, and M. Gómez (2005), Survey explores active tectonics in northern 

Caribbean. Eos Trans. AGU, 86(51), 537, 540. 

Kendall, M.S., M.E. Monaco, K.R. Buja, J.D. Christensen, C.R. Kruer, and M. Finkbeiner, R.A. Warner. 2001. (Online). Methods Used to Map the Benthic Habitats of Puerto Rico and the U.S. Virgin Islands URL: 

http://biogeo.nos.noaa.gov/projects/mapping/caribbean/startup.htm. 

Martinez, R., G. Cintrón, L. A. Encarnacion. 1979. Mangroves in Puerto Rico: A Structural Inventory. Department 

of Natural Resources, San Juan PR, USA, 149 p.

ten Brink, U.S., and Smith, S., 2003, High-resolution bathymetric map for the Puerto Rico trench; implications for 

earthquake and tsunami hazards [abs.]: Seismological Research Letters, San Juan, P.R., 30 April-2 May 2003, v. 74, 

p. 230. 

ten Brink, U.S., W. Danforth, C. Polloni, B. Andrews, Pl Llanes, S. Smith, E. Parker, and T. Uozumi (2004), New 

seafloor map of the Puerto Rico Trench helps assess earthquake and tsunami hazards. Eos Trans. AGU, 85(37), 349, 

354. 

U.S. National Oceanic and Atmospheric Administration. National Ocean Service, National Centers for Coastal 

Ocean Science Biogeography Program. 2001. (CD-ROM). Benthic Habitats of Puerto Rico and the U.S.Virgin 

Islands. Silver Spring, MD: National Oceanic and Atmospheric Administration. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 23

Zilkoski, D.B., Power Point Presentation, Spatial Reference Seminar, University of California, Riverside, CA, 20 

October 2004. 

http://138.23.217.17/jwilbur/student_files/Spatial%20Reference%20Seminar/dzilkoski.ppt 

APPENDIX A. VERTICAL DATUM TRANSFORMATION DESCRIPTION

Tidal datums are defined by ocean coastal water levels at particular stages of the tidal cycle. Given that ocean 

water levels are strongly influenced by gravity, tidal datums relate closely to gravitationally defined geoidal datums. 

Tidal datums are also the most traditional of vertical datums, with elevations most frequently referenced to Mean 

Sea Level (MSL) and hydrographic depths referenced to Mean Lower Low Water (MLLW). Referencing depths to 

MLLW provides a minimum value estimate of depth to accommodate a given ship draft, thereby maximizing 

navigational safety. Similarly, air gap, the clearance between the water surface and an overlying structure such as a 

bridge is measured with respect to Mean High Water (MHW), to give a conservative, minimum estimate of that 

clearance. The important characteristics of tidal datums are: 

1) They are a spatially variable surface, defined by the characteristics of the tide at any given location, 

2) They are defined by averages over a 19-year period in order to include the entire 18.6 year astronomical 

cycle that accounts for all significant variations in the moon and sun that cause slowly varying changes in 

the range of tide, and 

3) They vary over time, from 19-year epoch to 19-year epoch. 

Ellipsoidal datums are referenced to an ellipsoid of revolution, about its minor axis, making them axially 

symmetric, as would be expected from a rotating body, such as the earth. The ellipsoid is calculated to best fit to an 

equipotential surface of the earth's gravity field, the geoid, which is defined by multiple observations including 

direct gravity measurements, satellite altimetry, vertical deflections, etc. The ellipsoid is a very simple mathematical 

surface, defined by two parameters: the semi-major axis, ‘a’, the distance from the center to the surface at the 

equator, and the semi-minor axis, 'b,' the distance from the center to the surface at the pole. This simplicity makes 

ellipsoids an attractive reference frame. 

Geoidal datums are referenced to a geoid, an equipotential gravity surface for the earth (Fig. A-1). An 

equipotential surface is a surface of equal gravitational energy and can be thought of as a surface of equal gravity, 

recognizing that gravity grows weaker with distance from the earth. Geoidal surfaces are spatially variant, rising in 

areas of increased gravity and dropping in areas of decreased gravity. The area in the vicinity of Puerto Rico is one 

of decreased gravity because of the effect of the Puerto Rico Trench, just to the north of the island. The decrease in 

gravity corresponds to the decrease in mass since the trench is filled with water, which is of lower density than that 

of the surrounding seafloor rocks.
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 24

Figure A-1. Geoid surface near Puerto Rico. Geoid heights range from -70.8m (magenta) to -34.4m 

(red). Note the extreme low north of the island, due to the Puerto Rico Trench and the gradient 

adjacent to the trench. 

Terminology 

A clear understanding of the following terms is essential to making the proper vertical adjustments and 

transformations, as well as understanding the limitation of available data and the uncertainties those limitation 

impose on the final data sets. 

Ellipsoid Height: The signed height (positive up, away from the earth), perpendicular to the ellipsoid, from the 

ellipsoid to the point being measured. For the San Juan benchmark, 1.334 meters above MSL, the ellipsoid height is 

-41.66 meters or 41.66 meters earthward (below) the WGS84 Ellipsoid. 

Geoid Height: The signed height (positive up, away from the earth), perpendicular to the ellipsoid, from the 

ellipsoid to the geoid at a given geographic location. For the San Juan benchmark, the geoid height is -45.26 meters. 

This is consistent with the fact that the geoid is close to MSL. 

Orthometric Height: The height (positive up, away from the earth), along a plumb line, from the geoid to the point 

being measured. A plumb line is defined by the path, which is continually perpendicular to the gravitational 

equipotential surface. It corresponds to the direction defined by a falling object, which is gravitationally "down." 

The illustration below demonstrates the relationship between these three heights: 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 25

Figure A-2: Definitions of heights with respect to the Ellipsoid and Geoid from Zilkoski (2004). 

Elevation: A loosely defined term, nominally the height, along a plumb line, from MSL or the geoid, where MSL is 

not available, to the point being measured. The elevation of the San Juan benchmark is 1.334 meters, referenced to 

the Puerto Rico Vertical Datum of 2002 (PRVD02), i.e. MSL. 

Mean Lower Low Water (MLLW): The tidal datum defined by the average of the lower low water height of each 

tidal day observed over the National Tidal Datum Epoch. For stations with shorter series, simultaneous 

observational comparisons are made with a control tide station in order to derive the equivalent datum of the 

National Tidal Datum Epoch. The National Tidal Datum Epoch is a specific 19-year period over which tide 

observations are taken to determine Mean Sea Level and other tidal datums such as Mean Lower Low Water and 

Mean High Water. The latest update defines the 19-year period as 1983-2001. The MLLW tidal datum is used for 

soundings (depths) on nautical charts to provide a conservative, minimum estimate of depth for safe passage of 

vessels. 

Mean Sea Level (MSL): The average elevation of the sea surface, averaged over the 18.6 year astronomical cycle of 

tide generating forces. Another definition refers to the still water level, where the winds, waves, and tides are 

averaged out over a long observation period. The difficulty with both definitions is that sea level, and in fact all tidal 

datums, is rising at the measurable rate of about 3 mm per year, resulting in a 60 mm sea level rise over an 18.6 year 

averaging period. Furthermore, sea level is frequently measured with respect to a benchmark on land, giving a 

relative measurement of movement of the sea with respect to the land. In some places, clearly identifiable land 

motions, such as uplift due to glacial rebound (Maine), subsidence due to fluid withdrawal (Long Beach, CA), or 

changes due to earthquake (Anchorage, AK), produce significant changes in sea level, not totally attributable to the 

sea. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 26

Mean Tide Level (MTL): The tidal datum defined by the arithmetic mean of mean high water and mean low water. 

This is an average of averages and does not necessarily equal Mean Sea Level (MSL). 

Mean High Water (MHW): The tidal datum defined by the average of all the high water heights observed over the 

National Tidal Datum Epoch. For stations with shorter series, simultaneous observational comparisons are made 

with a control tide station in order to derive the equivalent datum of the National Tidal Datum Epoch. This datum is 

used to define the shoreline, the land surface intersection with MHW. MHW is the datum from which air gap, or 

bridge clearance, is measured, to provide a conservative, minimum estimate of that clearance for safe passage of 

vessels. 

Algebra, Vectors, and Signs. 

In discussions of various elevations and conversions from one datum to another, virtually everything is relative, and 

care must be taken to compare entities, which are both relative to the same datum or reference. In the definitions 

above, both the sign of the direction, nominally positive "up," away from the center of the Earth, and the reference 

direction, from one surface, to another were specified. Vectors are useful for specifying such entities, having both a 

magnitude and a direction. In Figure A-2 above, both Ellipsoid Height and Geoid Height are vector quantities, 

having magnitude and a single direction. Note that Orthometric Height has magnitude, but lies along a curved path 

with more than a single direction. Thus the equation in Figure A-2 is only approximate. 

In converting from Ellipsoid to Mean High Water (MHW), changes in magnitude and signs between datums must be 

carefully taken into account. In general, given two measurements relative to the same datum, A and B, (e.g. MSL 

and MHW, both relative to MLLW), subtracting one (the subtrahend) from the other (the minuend) results in the 

measurement (the difference) of the latter, the minuend, relative to the former, the subtrahend. 

Thus: A - B = D, 

or 

MSL-MHW=Distance, and direction, from MHW to MSL, 

(MSL relative to MHW). 

This is a negative number, representing distance, in a downward direction, from MHW to MSL. 

Tidal and Geodetic Data and Data Sources. 

Puerto Rico has a limited number of tide and geodetic stations. For all such stations, we obtained a "Data Sheet," 

which fully describes the station, including its location as well as position, and heights with respect to various 

datums. For our final analysis, we identified four useful stations: a tidal station at Mayagüez, a tidal and geodetic 

station at San Juan, and four CORS (Continually Operating Receiving Station – Global Positioning System) 

Stations. 

Tidal Stations 

An average of the values from the two available tidal stations, Mayagüez and San Juan, on the Island of Puerto Rico 

were calculated (MSL = 0.221 meters above MLLW and MHW = 0.386 meters above MLLW). The San Juan 

station has both geodetic and tidal data, thus serves to establish the tie between the geoid and tidal datums. 

Table A-1. Tidal Datum Values for Puerto Rico, n/a: not available, n/c: not computed 

Tidal Bench Tidal Datums 

Mark PID Name MLLW MLW MSL MTL MHW MHHW 

975 5371 TV1513 San Juan 0.000 n/a 0.234 n/a 0.400 n/a 

975 9394 [None] Mayagüez 0.000 0.050 0.208 0.211 0.372 0.427 

 Average: 0.000 n/c 0.221 n/c 0.386 n/c 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 27

Geodetic Stations 

We were able to locate Data Sheets for 114 geodetic stations on Puerto Rico, six of which were clustered on La 

Puntilla, Old San Juan, thus were geographically redundant. They provide a measure of the precision of Geoid 

Height determination. 

Table A-2: Ellipsoid, Geoid, and Elevation Heights for San Juan, Puerto Rico 

 Position Heights 

PID Name Latitude Longitude Ellips Geoid PRVD02 

AA7648 San Juan 18°27'33.0"N 66°06'59.0"W -45.27 1.447 

TV1513 San Juan 18°27'32.2"N 66°06'59.5"W -41.66 -45.26 1.334 

AA7649 San Juan 18°27'35.0"N 66°06'57.0"W -45.28 1.421 

AA7650 San Juan 18°27'39.0"N 66°06'58.0"W -45.30 1.998 

AA7651 San Juan 18°27'37.0"N 66°07'01.0"W -45.29 1.557 

AA7652a San Juan 18°27'37.0"N 66°07'03.0"W -45.29 1.515 

The San Juan stations, all at 18°28'N, 66°07'W provide the estimate of certainty in Geoid Height, with an 

average of -45.28 meters and a standard deviation of 0.0147 meters. The implication of the standard deviation is that 

the geoid height is known only to a precision of two standard deviations, 0.0294 meters, roughly 3 cm, with 67% 

confidence. The San Juan station, TV1513, serves is the single tie point between the Tidal Datums and the Geodetic 

Datums. 

With the addition of these CORS data, enough points are available to make a reasonable comparison between 

the observed geoid height and that predicted by a geoid model. We used the GEOID99 model from the NOAA 

National Geodetic Service (NGS) as an estimator of the MHW datum, offset by a constant. We then used the model 

and a calculated offset constant to adjust Ellipsoidal Heights to elevations or depths with respect to MHW. The 

specifics of this process involved downloading the GEOID99 and using it to estimate the geoid height at all 

elevation points, measured with respect to the ellipsoid. 

Corrections and Adjustments 

The heights and depths in our final output are to be referenced to a tidal datum, MHW. Source data of depths 

and elevations come from a number of sources, referenced to a number of datums: 

1. Ellipsoid for USDA/USACE topographic LiDAR data, which were collected with GPS navigation, 

2. MLLW and MLW for NOS hydrographic sounding data, 

3. Geoid for some data sets that have been partially adjusted. 

Applying corrections to each of these types of referenced data requires knowledge of Geoid Height and Tidal 

datum differences as well as the Tidal Datum Height referenced to the Geoid. 

Beginning with a coastal Ellipsoidal height measurement, referencing Figure A-3, and abiding by the sign 

conventions described above, 

1. The Ellipsoidal Height would be a negative number, because its elevation is below (earthward from) the 

Ellipsoid. 

2. The Geoid Height, a negative number extracted from the Geiod99 interpolated grid, is subtracted from the 

Ellipsoid Height. This is subtracting a negative number, algebraically equivalent to adding the absolute 

value of the Geoid Height. Since we have subtracted 1) the Geoid Height (height of the Geoid with respect 

to the Ellipsoid) from 2) the Ellipsoid Height (height of the measurement with respect to the Ellipsoid), the 

result is 3) the height of the measurement with respect to the Geoid. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 28

Figure A-3. Height-datum relationships. 

3. Finally, the difference between the Geoid and the Tidal Datum (MHW) must be included. This entails 

subtracting the height of MHW with respect to the Geoid from the result in Step 2, which is the measured 

elevation with respect to the Geoid. Again, subtracting 1) the height of MHW with respect to the Geoid 

from 2) the measured elevation with respect to the Geoid results in 3) the value of the measured elevation 

with respect to MHW. 

Using numbers from the available values for the San Juan Benchmark, TV1513 (Table A-1): 

1. The Ellipsoidal Height of the Benchmark is -41.66 meters. 

2. The Geoid Height at the Benchmark, is -45.26 meters. 

3. The elevation of the Benchmark with respect to PRVD02, Mean Sea Level, is 1.334 meters, which, when 

combined with other data, will yield the MHW elevation with respect to the Geoid. 

From Table A-1: 

4. The Puerto Rican difference from average MLLW to MHW is +0.386 meters. 

5. The Puerto Rican difference from average MLLW to MSL is +0.221 meters. 

6. The Puerto Rican difference between average MHW and MSL is (0.386 – 0.221) = +0.165 meters, the 

height of MHW with respect to MSL. 

The difference between the Tidal Datum and the Geoid must be calculated at the tie point of Benchmark 

TV1513 (the only location on Puerto Rico where we have all the necessary components to make this 

calculation). 

7. The Benchmark is -41.66 meters (below) the ellipsoid, the Geoid, at the same point is -45.26 meters 

(below) the ellipsoid, and the Benchmark is 1.334 meters above MSL. 

8. The Geoid Height, -45.26 meters, is equal to the sum of: a) the Benchmark Ellipsoid Height, -41.66 meters, 

b) the negative of the Benchmark Height relative to MSL, -1.334 meters, c) the Height of MLLW with 

respect to MSL, -0.221 meters, and d) a difference term, which relates the tidal datums to the Geoid. 

9. That difference is +2.045 meters from the Geoid to MLLW. 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 29

10. Adding the average MHW with respect to MLLW (0.386 meters), yields an adjustment of +2.431 meters 

from Geoid to MHW. 

To complete the calculation 

3⁄4 The Ellipsoidal Height is -41.66 meters. 

3⁄4 Subtract the Geoid Height of -45.26 meters (minus a minus) to get +3.6 meters, the elevation of the 

benchmark above the Geoid. 

3⁄4 Subtract the height of MHW, the Tidal Datum, above the Geoid, 2.431 meters, to get +1.169 meters, the 

height of the benchmark above MHW. 

3⁄4 Check and confirm in this case, average MSL with respect to MHW is -0.165 meters (value 6, above), 

which, when subtracted from 1.169, equals 1.334, the given elevation on the data sheet, with respect to 

PRVD02. 

Figure A-4. Final Adjustment Values for Puerto Rico, Black are given values, blue are averages, and red are calculated values. 

Values Used for Puerto Rico Datum Conversion 

1) Tidal Datum Information 

Average MHW – MLLW: +0.386 meters 

Average MSL – MLLW: +0.221 meters 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 30

2) Geoidal Height: 

Described by a Grid based on GEOID99 

3) Geoid to MHW Adjustment Term 

MHW – Geoid: +2.431 meters 

NAVD88 to MHW Correction: 

MHW is, on average, 0.165 meters above mean sea level, based on two stations in Puerto Rico, San Juan and 

Mayagüez. The National Elevation Dataset (NED) data and the photometrically derived elevations from the Puerto 

Rico Office of Planning and Budget were adjusted by -0.165 meters to convert from a NAVD88 (MSL) datum to a 

Mean High Water datum. 

 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 31

NGS DATA SHEET TV1513 

DATABASE = Sybase ,PROGRAM = datasheet, VERSION = 7.30 

1 National Geodetic Survey, Retrieval Date = FEBRUARY 1, 2006 

TV1513 

*********************************************************************** 

TV1513 TIDAL BM -This is a Tidal Bench Mark. 

TV1513 DESIGNATION -975 5371 A TIDAL 

TV1513 PID -TV1513 

TV1513 STATE/COUNTY-PR/PUERTO RICO 

TV1513 USGS QUAD - 

TV1513 

TV1513 *CURRENT SURVEY CONTROL 

TV1513 ___________________________________________________________________ 

TV1513* NAD 83(2002)-18 27 32.23680(N) 066 06 59.20580(W) ADJUSTED 

TV1513* PRVD02 -1.334 (meters) 4.38 (feet) ADJUSTED 

TV1513 ___________________________________________________________________ 

TV1513 X -2,450,319.715 (meters) COMP 

TV1513 Y --5,533,748.475 (meters) COMP 

TV1513 Z -2,006,620.132 (meters) COMP 

TV1513 LAPLACE CORR-0.30 (seconds) DEFLEC99 

TV1513 ELLIP HEIGHT--41.66 (meters) (05/06/04) GPS OBS 

TV1513 GEOID HEIGHT--45.26 (meters) GEOID99 

TV1513 DYNAMIC HT -1.331 (meters) 4.37 (feet) COMP 

TV1513 MODELED GRAV-978,668.5 (mgal) NAVD 88 

TV1513 

TV1513 HORZ ORDER -FIRST 

TV1513 VERT ORDER -FIRST CLASS II 

TV1513 ELLP ORDER -FOURTH CLASS I 

TV1513 

TV1513.The horizontal coordinates were established by GPS observations 

TV1513.and adjusted by the National Geodetic Survey in May 2004. 

TV1513.This is a SPECIAL STATUS position. See SPECIAL STATUS under the 

TV1513.DATUM ITEM on the data sheet items page. 

TV1513 

TV1513.The orthometric height was determined by differential leveling 

TV1513.and adjusted by the National Geodetic Survey in November 2002. 

TV1513 

TV1513.This Tidal Bench Mark is designated as VM 1386 

TV1513.by the Center for Operational Oceanographic Products and Services. 

TV1513 

TV1513.Photographs are available for this station. 

TV1513 

TV1513.The X, Y, and Z were computed from the position and the ellipsoidal 

ht. 

TV1513 

TV1513.The Laplace correction was computed from DEFLEC99 derived deflections. 

TV1513 

TV1513.The ellipsoidal height was determined by GPS observations 

TV1513.and is referenced to NAD 83. 

TV1513 

TV1513.The geoid height was determined by GEOID99. 

TV1513 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 32

TV1513.The dynamic height is computed by dividing the NAVD 88 

TV1513.geopotential number by the normal gravity value computed on the 

TV1513.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 

TV1513.degrees latitude (g = 980.6199 gals.). 

TV1513 

TV1513.The modeled gravity was interpolated from observed gravity values. 

TV1513 

TV1513; North East Units Scale Factor Converg. 

TV1513;SPC PRVI -269,274.029 233,472.092 MT 1.00000165 +0 05 56.9 

TV1513;UTM 19 - 2,043,391.781 804,564.644 MT 1.00074692 +0 54 49.4 

TV1513 

TV1513! -Elev Factor x Scale Factor = Combined Factor 

TV1513!SPC PRVI -1.00000655 x 1.00000165 = 1.00000820 

TV1513!UTM 19 -1.00000655 x 1.00074692 = 1.00075347 

TV1513 

TV1513 SUPERSEDED SURVEY CONTROL 

TV1513 

TV1513 NAD 83(1997)-18 27 32.23507(N) 066 06 59.20832(W) AD( ) 1 

TV1513 ELLIP H (05/12/97) -41.56 (m) GP( ) 4 2 

TV1513 ELLIP H (11/17/95) -41.61 (m) GP( ) 1 2 

TV1513 NAD 83(1993)-18 27 32.23272(N) 066 06 59.21837(W) AD( ) 1 

TV1513 ELLIP H (01/13/94) -41.46 (m) GP( ) 4 1 

TV1513 

TV1513.Superseded values are not recommended for survey control. 

TV1513.NGS no longer adjusts projects to the PR datum. 

TV1513.See file dsdata.txt to determine how the superseded data were derived. 

TV1513 

TV1513_U.S. NATIONAL GRID SPATIAL ADDRESS: 19QHA0456543392(NAD 83) 

TV1513_MARKER: DJ = TIDAL STATION DISK 

TV1513_SETTING: 32 = SET IN A RETAINING WALL OR CONCRETE LEDGE 

TV1513_SP_SET: SEAWALL 

TV1513_STAMPING: 5371 A 1977 

TV1513_MARK LOGO: NOS 

TV1513_MAGNETIC: N = NO MAGNETIC MATERIAL 

TV1513_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO 

TV1513+STABILITY: SURFACE MOTION 

TV1513_SATELLITE: THE SITE LOCATION WAS REPORTED AS SUITABLE FOR 

TV1513+SATELLITE: SATELLITE OBSERVATIONS - May 24, 2004 

TV1513 

TV1513 HISTORY - Date Condition Report By 

TV1513 HISTORY - 1977 MONUMENTED NOS 

TV1513 HISTORY - 19950620 GOOD NGS 

TV1513 HISTORY - 19950912 GOOD NGS 

TV1513 HISTORY - 20020125 GOOD NGS 

TV1513 HISTORY - 20020510 GOOD NGS 

TV1513 HISTORY - 20030203 GOOD NGS 

TV1513 HISTORY - 20040524 GOOD COMPA 

TV1513 

TV1513 STATION DESCRIPTION 

TV1513 

TV1513'DESCRIBED BY NATIONAL OCEAN SERVICE 1977 

TV1513'THE STATION IS LOCATED AT THE SOUTH END OF THE COAST GUARD STATION IN 

TV1513'OLD SAN JUAN. TO REACH SAY YA HOO AND DRIVE LIKE CRAZY. 

TV1513'THE DISK IS SET FLUSH IN THE TOP OF THE CONCRETE SEA WALL. IT IS 20.4 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 33

TV1513'M (66.9 FT) SOUTHEAST OF A STEEL FLAGPOLE, 6.1 M (20.0 FT) SOUTHWEST 

TV1513'OF THE NORTH CORNER OF THE NOS TIDE HOUSE AND 0.9 M (3.0 FT) NORTH OF 

TV1513'THE SOUTH FACE OF SEA WALL AND 0.2 M (0.7 FT) ABOVE THE GROUND. 

TV1513 

TV1513 STATION RECOVERY (1995) 

TV1513 

TV1513'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1995 (CSM) 

TV1513'STATION IS LOCATED AT THE OLD SAN JUAN U.S. COAST GUARD BASE NEAR THE 

TV1513'EXTREME SOUTHERN POINT OF THE BASE (LA PUNTILLA) NEAR THE EAST END OF 

TV1513'A CONCRETE QUAY. THE STATION MAY BE REACHED FROM THE SAN JUAN LUIS 

TV1513'MUNOZ MARIN INTERNATIONAL AIRPORT BY TAKING HIGHWAY 26 WEST TO THE 

TV1513'JUNCTION WITH HWY 25 THEN PROCEED NORTH AND WEST ON HWY 25 ALONG THE 

TV1513'NORTH SIDE OF OLD SAN JUAN TO A POINT JUST WEST OF FORT SAN CRISTOBAL. 

TV1513'FROM THIS POINT MEANDER WEST AND SOUTH ON ONE WAY ROADS WHICH ARE NOT 

TV1513'WELL MARKED TO A ROAD LEADING SSE JUST EAST OF THE CUSTOMS HOUSE, TAKE 

TV1513'THE ROAD LEADING SSE TO ITS END AT THE GATE OF THE COAST GUARD BASE. 

TV1513'FROM THE GATE PROCEED SOUTH AND EAST TO THE CONCRETE DOCKS THEN 

TV1513'PROCEED SOUTH AND SOUTHEAST ALONG THE CONCRETE DOCK TO ITS END AT THE 

TV1513'NOS TIDE HOUSE AND THE STATION TO THE RIGHT IN A SHORT SECTION OF 

TV1513'SEAWALL JUTTING NORTHWEST FROM THE SOUTHERNMOST CORNER OF THE SEAWALL. 

TV1513'THE MARK IS AN NOS TIDAL BENCH MARK DISK WITH A CENTER CROSS STAMPED. 

TV1513'MARK IS REPORTEDLY THE PRIMARY BENCH MARK OF NOS TIDE STATION 

TV1513'975-5371, SAN JUAN, LA PUNTILLA, SAN JUAN BAY. IT IS, 20.1 FT (6.1 M) 

TV1513'NORTHWEST OF THE NORTH CORNER OF THE TIDEHOUSE, 3.1 FT (0.9 M) 

TV1513'NORTHEAST OF THE SOUTHWEST FACE OF THE SEAWALL ABOUT 0.8 FT (24.4 CM) 

TV1513'ABOVE GROUND LEVEL. DESCRIBED BY C.S. MIDDLETON JR. 

TV1513 

TV1513 STATION RECOVERY (1995) 

TV1513 

TV1513'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1995 (JHR) 

TV1513'ADJUSTMENT ID=00000122 (DATUM=LT) 

TV1513' 

TV1513'COMPUTATION OF HEIGHT FOR CONSTRAINT FOLLOWS... 

TV1513' 

TV1513'DATA PUBLISHED 09/06/1989 FOR SAN JUAN, LA PUNTILLA, SAN JUAN BAY, 

TV1513'TIDE STATION 975 5371 BASED ON THE FOLLOWINGTV1513' 

TV1513'LENGTH OF SERIES = 10 YEARS 

TV1513'TIME PERIOD = 1978-1987 

TV1513'TIDAL EPOCH = 1960-1978 

TV1513'CONTROL TIDE STATION = KEY WEST (872 4580) 

TV1513' 

TV1513'BENCH MARK ELEVATION INFORMATION 

TV1513' ELEVATION IN FEET ABOVE 

TV1513' BENCH MARK STAMPING MLLW MHW 

TV1513' 5371 A 1977 5.32 3.99 

TV1513' 

TV1513'ACCEPTED STATION DATUMS FOR 1960-1978 FOR TIDE STATION 975 5371, 

TV1513'DATA RETRIEVED IN SEPTEMBER OF 1995- 

TV1513'MHW - MSL = 1.381 - 1.213 = 0.168 METER = 0.55 FOOT 

TV1513' 

TV1513'1989 MHW + 1995 (MHW-MSL) = 3.99 + 0.55 = 4.54 FEET = 1.384 METERS 

TV1513' 

TV1513' 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 34

TV1513'COMPUTATION OF GRAVITY PREDICTION FOLLOWS... 

TV1513' 

TV1513'LATITUDE LONGITUDE HEIGHT BOUG ANOM 

TV1513'(DEC DEG) (DEC DEG) (M) (MGAL) 

TV1513'18.46000 66.11667 1.384 978.6685 

TV1513 

TV1513 STATION RECOVERY (2002) 

TV1513 

TV1513'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 2002 (JMW) 

TV1513'4.8 KM (3.0 MI) NORTHERLY ALONG STATE HIGHWAY 25 FROM THE JUNCTION OF 

TV1513'STATE HIGHWAY 2 IN SAN JUAN, THENCE 0.3 KM (0.2 MI) SOUTHERLY AND 

TV1513'THEN WESTERLY ALONG ONE WAY STREETS TO A TRAFFIC CIRCLE NEAR A U.S. 

TV1513'CUSTOMS BUILDING, THENCE 0.3 KM (0.2 MI) SOUTHWESTERLY ALONG A PAVED 

TV1513'ROAD ON THE WEST SIDE OF THE BUILDING TO THE LA PUNTILLA U.S. COAST 

TV1513'GUARD STATION SECURITY GATE, THENCE 0.2 KM (0.125 MI) SOUTHERLY ALONG 

TV1513'A PAVED ROAD TO A SEAWALL, THENCE 0.05 KM (0.03 MI) SOUTHWESTERLY TO 

TV1513'THE END OF THE SEAWALL, 8.4 M NORTHWEST OF THE SOUTH CORNER OF THE 

TV1513'SEAWALL, 4.1 M NORTHWEST OF THE NORTHWEST CORNER OF A TIDE GAUGE 

TV1513'BUILDING, 3.1 M NORTHWEST OF BENCH MARK SJH 44, 1.6 M SOUTHEAST OF A 

TV1513'CHAIN-LINK FENCE, AND 1.0 M NORTHEAST OF THE SOUTHWEST FACE OF THE 

TV1513'SEAWALL. NOTE--THE MARK IS ON PROPERTY OWNED BY THE U.S. GOVERNMENT 

TV1513'AND THE U.S. COAST GUARD, CONTACT JORGE R. GAUDIER, 5 CALLE LA 

TV1513'PUNTILLA, SAN JUAN, PR 00910, PHONE 787-729-4304. 

TV1513 

TV1513 STATION RECOVERY (2002) 

TV1513 

TV1513'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 2002 (JMW) 

TV1513'RECOVERED AS DESCRIBED. 

TV1513 

TV1513 STATION RECOVERY (2003) 

TV1513 

TV1513'RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 2003 (DRD) 

TV1513'PUERTO RICO VERTICAL DATUM OF 2002 (PRVD02) 

TV1513' 

TV1513'COMPUTATION OF HEIGHT FOR CONSTRAINT FOLLOWS... 

TV1513' 

TV1513'USING DATA WITH A WORKING DATE OF 11/18/2002 FOR 

TV1513'SAN JUAN, LA PUNTILLA, SAN JUAN BAY, PUERTO RICO, 

TV1513'TIDE STATION 975 5371 BASED ON THE FOLLOWINGTV1513' 

TV1513'LENGTH OF SERIES = 17 YEARS 

TV1513'TIME PERIOD = 1/1/1983 - 12/31/1987, 

TV1513' 1/1/1990 - 12/31/2001 

TV1513'TIDAL EPOCH = 1983-2001 

TV1513' 

TV1513'BENCH MARK ELEVATION INFORMATION IN METERS ABOVE 

TV1513' 

TV1513' STAMPING OR DESIGNATION MLLW MHW 

TV1513' 

TV1513' 5371 A 1977 1.568 1.168 

TV1513' 

TV1513'USING ELEVATIONS OF MEAN HIGH WATER (MHW) AND MEAN SEA LEVEL (MSL) 

TV1513'TIDAL DATUMS REFERRED TO MEAN LOWER LOW WATER (MLLW), IN METERS 
DIGITAL ELEVATION MODELS FOR SAN JUAN AND MAYAGÜEZ, PUERTO RICO 35

TV1513' 

TV1513'(MHW - MSL) = 0.400 - 0.234 = 0.166 METER 

TV1513' 

TV1513'(MHW - MSL) + MHW FOR 5371 A 1977 = 0.166 + 1.168 = 1.334 METERS 

TV1513' 

TV1513' 

TV1513'THE ORTHOMETRIC HEIGHTS RESULTING FROM THE PRVD02 ADJUSTMENT DONE IN 

TV1513'THE SPRING OF 2003 WERE COMPUTED BASED ON NORMAL GRAVITY (SEE USC+GS 

TV1513'SPECIAL PUBLICATION 240). 

TV1513' 

TV1513'NOTE--'TRUE' ORTHOMETRIC HEIGHTS WILL BE RECOMPUTED LATER WHEN ACTUAL 

TV1513'GRAVITY VALUES ARE AVAILABLE IN PUERTO RICO. 

TV1513 

TV1513 STATION RECOVERY (2004) 

TV1513 

TV1513'RECOVERY NOTE BY COMPASSCOM INC 2004 (IR) 

TV1513'RECOVERED IN GOOD CONDITION.