Map files and sheets
- Paper maps and map books
- PDF, TIFF, JPEG and PNG
- GeoTIFF and available world files
- Adjoining or overlapping sheets
Paper and Scanned Maps to GIS-Ready Data
Convert Geological Maps into Structured GIS Data
GAEA converts paper, PDF and scanned geological maps into georeferenced point, line and polygon layers with agreed attributes, coordinate reference information and documented QA/QC.
GIS and CAD formats Documented georeferencing Geometry and attribute QA/QC
Accepted source material
Supply the Best Available Map and Reference Information
Original digital exports or high-resolution lossless scans preserve more detail than photocopies and compressed screenshots. Include every item needed to interpret symbols, coordinates and attributes.
Spatial reference material
- Coordinate grids and tick marks
- Control-point tables
- CRS, datum, units and EPSG code
- Existing GIS or CAD reference data
Interpretation material
- Complete legends and symbol keys
- Formation and feature codes
- Attribute definitions
- Known revisions or map corrections
Scan guidance: scan maps flat and square, retain the complete neatline, scale, north arrow, coordinate grid and legend, avoid image enhancement that removes fine linework, and preserve sheet overlaps needed for edge matching.
Layers and geometry
Convert Mapped Information into a Defined GIS Schema
The project scope identifies which features become points, lines or polygons and which attributes accompany each feature.
Locations and observations
Boreholes, wells, samples, outcrops, structural measurements, control points and named locations.
Linear features
Faults, contacts, folds, contours, rivers, roads, utilities, shorelines and section traces.
Mapped areas
Geological units, deposits, alteration zones, hazards, water bodies, properties and project boundaries.
Structured descriptions
Feature identifiers, unit codes, names, ages, types, certainty, source references and approved controlled values.
Schema decision: field names, data types, required values, null handling, code lists and source attribution should be agreed before production begins.
Available deliverables
Choose Formats That Match the Downstream Workflow
The quotation identifies which formats are included, the coordinate reference system, file naming, layer organization and accompanying documentation.
| Deliverable | Typical purpose | Project considerations |
|---|---|---|
| GeoPackage Preferred | Consolidated modern GIS delivery containing multiple vector layers and attributes. | Confirm layer names, field schema, CRS and any style files. |
| Esri Shapefile | Compatibility with established GIS workflows. | Field naming, text encoding and related sidecar files require care. |
| GeoJSON | Open data exchange and web-oriented mapping. | Coordinate convention, feature properties and file size should be reviewed. |
| KML / KMZ | Geographic viewing and presentation. | Symbology and attribute presentation are agreed by project. |
| DXF | CAD exchange for applicable point, line and polygon geometry. | Layer names, units, elevation handling and coordinate system must be defined. |
| Georeferenced GeoTIFF | Rectified source map retained as a GIS raster reference. | Transformation, resampling, CRS and transparency requirements are documented. |
| CSV tables | Coordinates, control points, attributes or delivery indexes. | Identifier relationships, units and coordinate fields must be explicit. |
| Delivery summary | Documents source files, CRS, layers, attributes, assumptions and QA/QC findings. | Project-specific limitations and unresolved items remain visible. |
Source and GIS output
Review the Transformation from Map Image to Structured Layers
A production project can preserve the georeferenced source raster while separating mapped information into queryable feature layers.
Downloadable synthetic exampleGIS Layer and Attribute Package
The package demonstrates a project boundary, geological-unit polygons, geological contacts, a fault, sample locations, control points and a layer dictionary.
Project boundary polygonGeological-unit polygonsContact and fault linesSample-location pointsControl-point registerLayer dictionary
CRS: EPSG:4326. All coordinates, geometry and attributes are synthetic and are not suitable for interpretation, design or regulatory use.
Download GIS example packageGeoreferencing requirements
Every Coordinate Requires a Documented Reference
GAEA will not silently assume an unknown projection, datum or unit. Unknown or conflicting spatial-reference information is identified during source review.
Information to provide
- Coordinate reference system and projection
- Horizontal datum and vertical datum where relevant
- Coordinate units and map scale
- EPSG code when known
- Reliable control-point coordinates
- Grid, neatline and tick-mark information
- Required transformation or client standard
- Reference GIS data for alignment checks
If the CRS or datum cannot be established, the output may be delivered in image coordinates or another explicitly documented local reference rather than being assigned an unsupported spatial reference.
Preferred control-point register
| ID | Source X/Y | Map X/Y | CRS |
|---|---|---|---|
| CP-01 | 125, 118 px | 500000, 5500000 | EPSG code |
| CP-02 | 1875, 120 px | 502500, 5500010 | Same CRS |
| CP-03 | 130, 1380 px | 500010, 5498000 | Same CRS |
Document by project: transformation method, control-point distribution, rejected points, residuals or RMSE where calculated, resampling method and any areas with insufficient control.
Quality assurance
A Defined Twelve-Stage Map QA/QC Workflow
Checks address the image, spatial reference, geometry, topology, attributes and final delivery package.
- Source reviewConfirm completeness, scale, legends, control and damaged areas.
- Scan preparationCrop carefully and correct rotation, skew and visible distortion.
- Control selectionChoose reliable, well-distributed reference points.
- GeoreferencingApply and document the agreed CRS and transformation.
- Layer setupCreate approved geometry types, fields and controlled values.
- Feature digitizationCapture points, lines and polygons at appropriate scale.
- Attribute entryTranscribe agreed identifiers and descriptive information.
- Geometry reviewCheck invalid shapes, duplication and unintended vertices.
- Topology reviewCheck gaps, overlaps, connectivity and shared boundaries.
- Edge matchingReconcile features crossing adjoining map sheets.
- Visual comparisonOverlay vector output on the source and inspect coverage.
- Delivery verificationConfirm formats, CRS, layers, attributes and documentation.
Pricing and schedule
Use the Per-Sheet Rate as a Preliminary Planning Value
A firm quotation follows review of representative source material and the required spatial, layer, attribute and delivery specifications.
What Counts as a Map Sheet?
A sheet is one source map page or scan treated as a production unit after review. Oversized panels, map books, tiled scans or several files representing one sheet may be divided or grouped in the final scope.
Digitization can start at US$500 per sheet
Preliminary example
4 comparable map sheets × US$500 = US$2,000 preliminary estimate
4 comparable map sheets × US$500 = US$2,000 preliminary estimate
This is not a binding quotation. It may not include difficult georeferencing, extensive attributes, dense linework, multiple output formats, edge matching, source repair or project-specific QA/QC.
Factors Affecting Final Cost and Timing
Sheet dimensions and number
Source clarity and condition
Feature and linework density
Number of GIS layers
Attribute transcription
Georeferencing complexity
Control-point availability
Edge matching between sheets
Output formats and styling
QA/QC and delivery schedule
Project process
Three Steps from Source Maps to Verified GIS Data
1
Review and Scope
Inspect representative maps and confirm layers, attributes, spatial reference, formats, limitations, pricing and acceptance requirements.
2
Digitize and Verify
Prepare and georeference the source, capture geometry and attributes, then perform spatial, topology and visual QA/QC.
3
Deliver and Document
Provide the agreed GIS, CAD and raster files with naming, CRS, schema, assumptions and project-specific limitations documented.
Include with the quotation request:
- Number of maps or sheets
- Representative source file
- Map dimensions and scale
- CRS, datum and units
- Available control points
- Required layers
- Attribute schema
- Output formats
- Required completion date
- Confidentiality requirements
Applications and responsible use
Bring Legacy Mapping into a Controlled Digital Workflow
Archive modernization
Preserve aging map collections as indexed raster and vector information.
GIS integration
Combine mapped features with project, borehole, sample and environmental data.
Geological interpretation
Use mapped contacts, structures and units as qualified interpretation inputs.
CAD exchange
Transfer applicable geometry into documented CAD layers and units.
Map comparison
Compare historical mapping with current project and reference information.
Data handoff
Deliver defined layers and attributes to consultants, clients and project teams.
Confidential Handling and Documented Limitations
Project maps and supporting information are handled as client-confidential data. Transfer, access, retention and deletion requirements can be agreed before work begins.
Digitized geometry should retain its relationship to the source map, revision and confidence. It should not be presented as newly surveyed ground truth or used beyond the accuracy supported by the source and georeferencing.
- Retain source and revision identifiers
- Document uncertain or inferred features
- Preserve project assumptions and exceptions
- Use qualified review for technical decisions
Knowledge Center
Continue Learning About Geological Map Digitization
Geoscience Data Digitization
Review a broader guide to converting legacy subsurface records.
Read the guideMaps for GIS and Subsurface Modeling
Explore map digitization for spatial analysis and interpretation.
Read the map guideDigitized Map Data Formats
Compare common raster, vector, GIS and CAD delivery options.
Read the format guideLegacy Geological Archives
Plan the conversion of historical collections into structured databases.
Read the archive guideMap Digitization and Digital Twins
Consider how converted maps support connected project information.
Read the digital-twin guideFrequently asked questions
Before You Submit a Geological Map
What map sources can GAEA digitize?
GAEA accepts paper maps and PDF, TIFF, JPEG, PNG and GeoTIFF files, along with map books, adjoining sheets, legends, coordinate grids, control-point tables and available reference data.
Which GIS and CAD formats are available?
Depending on the project scope, deliverables can include GeoPackage, Esri Shapefile, GeoJSON, KML or KMZ, DXF, georeferenced GeoTIFF and CSV coordinate tables.
Does digitization improve the accuracy of the original map?
No. Digitization reproduces information visible in the source. Positional and thematic accuracy remain limited by the original scale, source quality, distortion, control points, coordinate information and interpretation of indistinct features.
What coordinate information should be supplied?
Provide the coordinate reference system, datum, units, EPSG code when known, map scale, grid information and reliable control points. GAEA will not silently assume an unknown coordinate reference system.
Can attributes be entered with the map geometry?
Yes. Attribute entry can be included when the layer schema, field names, data types, controlled values and source of each attribute are agreed before production.
How is map digitization priced?
Pricing can start at US$500 per sheet. The final quotation depends on source condition, sheet size, feature density, number of layers, attributes, georeferencing, edge matching, output formats and QA/QC requirements.
Is the downloadable GIS package real project data?
No. The example contains entirely synthetic geometry and attributes in EPSG:4326. It is provided only to demonstrate a possible layer and delivery structure.
Have a Geological Map to Evaluate?
Send one representative source with its scale, legend, coordinate information and required layers. GAEA will confirm feasibility, assumptions, deliverables, schedule and price.
