GELE Surveying (Geomatics) — Route, Topographic and Modern SurveyingConcept Map

Concept

Topographic Surveying and Contours

Sub Concepts

• Contour lines and elevation representation
• Contour spacing and slope interpretation
• Contour patterns: ridges, valleys, and terrain features
• Contour interval selection and accuracy
• Digital elevation models (DEM) from topographic data

Relationship To Central

Core field method for recording 3D ground surface; foundation for mapping and design

Concept

Hydrographic Surveying

Sub Concepts

• Bathymetry and depth sounding
• Echo sounder and acoustic positioning
• Tidal datum and water level reference
• Shoreline delineation and breaklines
• Flow velocity measurement and discharge calculation

Relationship To Central

Specialized topographic survey method for water bodies; critical for maritime projects

Concept

Photogrammetry

Sub Concepts

• Vertical aerial photography and camera geometry
• Photo scale calculation: focal length and flying height
• Stereoscopic imaging and parallax
• Orthophoto generation and rectification
• Ground distance determination from photo measurements

Relationship To Central

Remote sensing technique for extracting measurements and ortho-imagery from photographs

Concept

Modern Positioning Technologies

Sub Concepts

• GPS/GNSS fundamentals and constellation
• Differential GPS (DGPS) and real-time kinematic (RTK)
• Total station: EDM + electronic angle measurement
• Robotic total station and automated surveying
• Integration with onboard computation and data logging

Relationship To Central

Advanced tools replacing conventional methods; enable cm-level accuracy for control and stake-out

Concept

Geographic Information Systems (GIS)

Sub Concepts

• Spatial data models: raster and vector
• Attribute databases and querying
• Layer management and visualization
• Spatial analysis and modeling
• Map production and reporting

Relationship To Central

Data management and spatial analysis platform; integrates all survey products

Concept

Route Surveying

Sub Concepts

• Alignment design and horizontal geometry
• Vertical curve design and grade line
• Cross-section surveying and volume calculations
• Staking and setting out procedures
• Engineering design integration (NSCP 2015 alignment standards)

Relationship To Central

Specialized application for linear projects; combines topographic and control methods

Concept

Control and Accuracy

Sub Concepts

• Horizontal and vertical control networks
• Accuracy standards and specifications
• Error propagation and uncertainty analysis
• Field verification and quality assurance
• Adjustment and coordinate transformation

Relationship To Central

Framework for ensuring quality and traceability of all survey work

To

Route Surveying

From

Topographic Surveying and Contours

Strength

strong

Relationship

Topographic data provides terrain baseline for route alignment design; contour interpretation guides slope and grade decisions

To

Hydrographic Surveying

From

Topographic Surveying and Contours

Strength

strong

Relationship

Both map 3D surface; hydrographic extends topographic principles to water bodies using echo sounders and bathymetric contours

To

Topographic Surveying and Contours

From

Photogrammetry

Strength

strong

Relationship

Aerial photos with stereoscopy enable rapid topographic mapping; photo measurements converted to ground distances using photo scale

To

Topographic Surveying and Contours

From

Modern Positioning Technologies

Strength

strong

Relationship

GNSS/RTK and total stations provide positioning for topographic detail surveys; establish control for contour mapping accuracy

To

Hydrographic Surveying

From

Modern Positioning Technologies

Strength

strong

Relationship

RTK GNSS on boats provides real-time horizontal positioning for sounding operations; critical for bathymetric accuracy

To

Photogrammetry

From

Modern Positioning Technologies

Strength

moderate

Relationship

GNSS ground control points establish coordinate frame for photo rectification and orthophoto generation; validate photo measurements

To

Route Surveying

From

Modern Positioning Technologies

Strength

strong

Relationship

RTK GNSS and total stations used for setting out alignments, staking, and as-built verification; primary positioning tool

To

Topographic Surveying and Contours

From

Geographic Information Systems (GIS)

Strength

strong

Relationship

GIS stores, manages, analyzes topographic data; creates DEM from contours; enables slope and aspect analysis

To

Photogrammetry

From

Geographic Information Systems (GIS)

Strength

moderate

Relationship

GIS integrates orthophoto mosaics and control point data; performs rectification verification and layer registration

To

Route Surveying

From

Geographic Information Systems (GIS)

Strength

strong

Relationship

GIS visualizes route alternatives, performs spatial analysis for alignment selection, manages cross-section and volume data

To

Hydrographic Surveying

From

Geographic Information Systems (GIS)

Strength

strong

Relationship

GIS creates bathymetric surface models, generates navigation charts, integrates shoreline and sounding data layers

To

Modern Positioning Technologies

From

Control and Accuracy

Strength

strong

Relationship

Accuracy standards define control network requirements; positioning methods must achieve specified order of accuracy

To

Topographic Surveying and Contours

From

Control and Accuracy

Strength

strong

Relationship

Horizontal/vertical control framework ensures contour mapping meets accuracy specifications; closure analysis validates survey quality

To

Photogrammetry

From

Control and Accuracy

Strength

moderate

Relationship

Ground control points and accuracy assessment calibrate photo measurements; error propagation analysis validates orthophoto precision

To

Route Surveying

From

Control and Accuracy

Strength

strong

Relationship

Route control networks established first; staking accuracy dependent on control quality; as-built verification confirms specification compliance

To

Topographic Surveying and Contours

From

Route Surveying

Strength

moderate

Relationship

Route surveys include cross-sections (mini-topographic surveys); contour map interpretation informs grade design

To

Modern Positioning Technologies

From

Photogrammetry

Strength

moderate

Relationship

Total stations/GNSS establish ground control for photo rectification; modern positioning validates photo scale measurements

To

Geographic Information Systems (GIS)

From

Hydrographic Surveying

Strength

strong

Relationship

Bathymetric data integrated as GIS raster/TIN layer; enables spatial analysis of navigation, dredging volumes, environmental assessment

To

Control and Accuracy

From

Route Surveying

Strength

strong

Relationship

Route projects establish project-level control networks; staking accuracy specifications derived from design requirements

To

Geographic Information Systems (GIS)

From

Photogrammetry

Strength

strong

Relationship

Orthophotos and aerial imagery serve as base layers in GIS; enable visual context for spatial analysis and map production