Data processing is the conversion of data into usable and desired form

Conversion or processing is carried out using a predefined sequence of operations either manually or automatically

Data collection processes; data capture, data automation, data conversion, data transfer, data translation, & digitizing

What type of data needs to be processed for cartographic purposes?

1. Vector data

• Digitization
• Field surveys using surveying techniques

2. Raster data

• Remote sensing by use of satellites, UAVs, Aerial photography
• Scanning

1. Collection
2. Storage
3. Sorting
4. Processing
5. Analysis
6. Presentations

Raster & vector are two methods that are used to reduce geographic phenomena to forms that can be coded in computer databases

Raster is preferred for continuous fields

Vector is preferred for discrete objects e.g. 0-dimension (points), 1-dimension (lines), 2-dimensions (areas, polygons)

Planning includes establishing user requirements, garnering resources, & developing a project plan

Preparation involves obtaining data, redrafting poor-quality map sources, editing scanned map images, removing noise, setting up appropriate Cartography hardware and software systems to accept data

Digitizing and transfer are the stages where the majority of the effort will be expended

Editing and improvement covers many techniques designed to validate data, as well as correct errors and improve quality

Evaluation is the process of identifying project successes and failures

Software

• Sensor - metric camera
• RTK-GPS set & RTK/PPK drone
• Planning & processing: Pix4D, DroneDeploy, DataMapper, PCI Geomatica & Agisoft Metashape

Data input & Processing; data reduction, editing

• Fieldwork: Recce >> Making & observe GCPs >> Aerial photography
• Data input: Control data & photographs
• Output: Orthomosaic, Digital Surface Model (DSM) or Digital Elevation Model (DEM), Topographic or Feature map & reports

Data storage & management operations

• Online repositories
• Hard disks

Software

• Sensor - landsat
• ENVI, ERDAS Imagine, TerrSet, PCI Geomatica

Data input & Processing; data reduction, editing

• Data input: grids (bands) with digital numbers (DN)
• Output: images, DEMs,maps etc
• Get software manuals for processing procedures

Data storage & management operations

• Online repositories
• Hard disks

Software

• Scanners
• Plotters
• Digitizers

Data input & Processing; data reduction, editing

• Data input: - hardcopy maps
• Processing: - steps of digitization
• Output: - digital maps

Data storage & management operations

• Online repositories
• Hard disks

Software

• Total station
• Post-processing software e.g. MS excel
• AutoCAD for plotting

Data input & Processing; data reduction, editing

• Data input: - CSV point data
• Processing: - AutoCAD, GIS softwares
• Output: - Cadastral, topographic maps

Data storage & management operations

• Online repositories
• Hard disks

Software

• GPS/GNSS set
• Post-processing tools e.g. listed here
• AutoCAD for plotting & drawing

Data input & Processing; data reduction, editing

• Data input: - CSV point data
• Processing: - AutoCAD, GIS softwares
• Output: - Cadastral, topographic maps

Data storage & management operations

• Online repositories
• Hard disks

Software

• Sensor - lidar
• ERDAS Imagine, ArcGIS, QGIS etc

Data input & Processing; data reduction, editing

• Data input: - Point Cloud
• Processing: - tutorial
• Output: - models, maps

Data storage & management operations

• Online repositories
• Hard disks

Queries about this Lesson, please send them to: jmwaura@jkuat.ac.ke

*References*

• Analytical and Computer Cartography, 2nd ed. Keith C. Claike
• Geographic Information Systems: The Microcomputer and Modern Cartography, 1st ed. Fraser Taylor