Geospatial Analysis with Igor Pro

Small DEM of the World.
Global Topography and Bathymetry

  • Import common GIS data formats.
  • Write some common GIS data formats.
  • Transform data between spatial reference systems.
  • Display data in 1D, 2D, and 3D graphs.
  • Analyze data using built-in and custom operations, functions, and procedures.

Igor Pro includes a variety of custom and general tools for importing, displaying, and analyzing geospatial data.

With Igor Pro you can work with standard geospatial data formats such as Shapefile and GeoTiff.

Igor imports both raster and vector GIS data. Raster data sets are arrays of gridded data points. These formats often represent 2D surfaces such as land topography or undersea bathymetry.

Vector data sets represent spatial objects as collections of points, lines and polygons. Vector data is well suited to representing spatial data as geographic boundaries. Examples include shorelines, rivers, roads, political divisions, and vessel paths. Vector data sets often contain additional non-spatial data such as name, population, or wikipedia URLs.

IgorGIS XOP

The new Igor GIS XOP greatly increases the number of readable formats, provides access to feature data in vector files, and handles spatial transformations of both vector and raster data using widely used spatial reference specifications.

With the IgorGIS package comes IgorGIS Procedures.ipf, a set of Igor functions making it easier to produce custom maps with GIS data. You can, for example, load a vector map of the United States, generate a fill image, color the states according to presidential election results, move Alaska and Hawaii to just west of California, and display state codes and electoral college votes on top of each state. As another example you can load vector maps of the countries of the world and of the world's cities, filter for cities tagged as "World Cities" by the data set, then plot those cities with circle size scaled to population and taged the city names.

2008 United States Presidential Electoral Map
USA Presidential Election
2008 Electoral College Results
Select European Cities
Select European and Surrounding Cities

Beginning with Igor 6.37 the IgorGIS XOP comes with Igor. You do have to activate it. See the "Activating the IgorGIS Package" help topic within Igor for instructions on activating IgorGIS. Simply type 'DisplayHelpTopic "Activating the IgorGIS Package"' into your Igor command window. A detailed IgorGIS tutorial can also be found within the IgorGIS Help.ihf file.

Sample Datasets

To facilitate users generating common geographical maps we have imported some public domain GIS data into Igor experiments and made those experiments available for free download. These datasets include global coastline, global cities, global country boundaries, global state and province boundaries, and a global topography relief raster. See Igor GIS data.

Global coastline Global Topographic Relief
Global Coastline Global Relief

Examples and Demos

Included with the Igor Pro installation are a number of example and demo files that will help you to get started with displaying and analyzing geospatial data. The GIS Utilities procedures include a comprehensive help file describing the various utilities and listing a wide variety of online repositories from which you can obtain data. The Half Dome Demo experiment file provides an introduction to the GISLoadWave XOP with an example of data import from a USGS SDTS DEM and DLG. The Map Projections Demo experiment file provides several examples demonstrating aspects of the built-in Project operation.

Igor Pro also comes with demo experiments that demonstrate some of the basic geospatial display capabilities to help you get started.

Pacific NW Earthquakes and Depth Profile California Earthquakes and Faults
US Pacific NW Earthquakes
and Crustal Profile
California Earthquakes
and Major Faults

Data Formats

Igor Pro GIS support includes specialized utilities for importing most open source geospatial data formats. The following table lists the readable GIS data formats. Note that the number of readable GIS formats has been greatly expanded with the introduction of the new IgorGIS XOP, with that expansion including the ubiquitous Shapefile and GeoTiff formats.

Raster Formats Vector/Line Formats
  • TIFF / BigTIFF / GeoTIFF (.tif)
  • Arc/Info ASCII Grid
  • ACE2
  • ADRG/ARC Digitized Raster Graphics (.gen/.thf)/
  • Arc/Info Binary Grid (.adf)
  • AIRSAR Polarimetric
  • Azavea Raster Grid
  • Magellan BLX Topo (.blx, .xlb)
  • Microsoft Win Device Independent Bitmap (.bmp)
  • BSB Nautical Chart Format (.kap)
  • VTP Binary Terrain Format (.bt)
  • CEOS (Spot for instance)
  • DRDC COASP SAR Processor Raster
  • TerraSAR-X Complex SAR Data Product
  • Convair PolGASP data
  • USGS LULC Composite Theme Grid
  • Spot DIMAP (metadata.dim)
  • ELAS DIPEx
  • First Generation USGS DOQ (.doq)
  • New Labelled USGS DOQ (.doq)
  • Military Elevation Data (.dt0, .dt1, .dt2)
  • Arc/Info Export E00 GRID
  • ECRG Table Of Contents (TOC.xml)
  • ESRI .hdr Labelled
  • Erdas Imagine Raw
  • NASA ELAS
  • ENVI .hdr Labelled Raster
  • ERMapper (.ers)
  • Envisat Image Product (.n1)
  • EOSAT FAST Format
  • FIT
  • Fuji BAS Scanner Image
  • Generic Binary (.hdr Labelled)
  • GSat File Format
  • Graphics Interchange Format (.gif)
  • WMO GRIB1/GRIB2 (.grb)
  • GRASS ASCII Grid
  • Golden Software ASCII & Binary Grid
  • Golden Software Surfer 7 Binary Grid
  • GSC Geogrid
  • NOAA .gtx vertical datum shift
  • GXF - Grid eXchange File
  • Hierarchical Data Format Release 4 (HDF4)
  • HF2/HFZ heightfield raster
  • Erdas Imagine (.img)
  • Image Display and Analysis (WinDisp)
  • ILWIS Raster Map (.mpr,.mpl)
  • Intergraph Raster
  • IRIS
  • USGS Astrogeology ISIS cube (Version 2&3)
  • JAXA PALSAR Product Reader (Level 1.1/1.5)
  • Japanese DEM (.mem)
  • JPEG JFIF (.jpg)
  • KMLSUPEROVERLAY
  • NOAA Polar Orbiter Level 1b Data Set (AVHRR)
  • Erdas 7.x .LAN and .GIS
  • FARSITE v.4 LCP Format
  • Daylon Leveller Heightfield
  • NADCON .los/.las Datum Grid Shift
  • OziExplorer .MAP
  • Vexcel MFF & MFF2
  • EUMETSAT Archive native (.nat)
  • NLAPS Data Format
  • NOAA NGS Geoid Height Grids
  • NITF (.ntf, .nsf, .gn?, .hr?, .ja?, .jg?, .jn?, .lf?, etc.)
  • NTv2 Datum Grid Shift
  • Northwood/VerticalMapper Classified & Numeric.grc/.tab
  • PCI .aux Labelled
  • PCI Geomatics Database File
  • PCRaster
  • NASA Planetary Data System
  • Portable Network Graphics (.png)
  • Netpbm (.ppm,.pgm)
  • R Object Data Store
  • Swedish Grid RIK (.rik)
  • Raster Matrix Format (*.rsw, .mtw)
  • Raster Product Format/RPF (CADRG, CIB)
  • RadarSat2 XML (product.xml)
  • Idrisi Raster
  • SAGA GIS Binary format
  • SAR CEOS (Radarsat and ERS)
  • USGS SDTS DEM (*CATD.DDF)
  • SGI Image Format
  • Snow Data Assimilation System
  • Standard Raster Product (ASRP/USRP)
  • SRTM HGT Format
  • Terragen Heightfield (.ter)
  • EarthWatch/DigitalGlobe .TIL
  • TerraSAR-X Product
  • USGS ASCII DEM / CDED (.dem)
  • ASCII Gridded XYZ
  • ZMap Plus Grid
  • USGS SDTS
  • USGS Seamless
  • GTOPO30
  • SRTM30
  • GLOBE
  • HYDRO1k
  • NIMA DTED Level 0
  • ETOPO2
  • ETOPO5
  • TOPEX
  • CDED - Canadian Digital Elevation Data
  • BIL - Band Interleaved by Line
  • ARCInfo ASCII Grid
  • GEODAS Grid - GRD98
  • ESI Shapefile
  • Aeronav FAA
  • Arc/Info Binary Coverage
  • Arc/Info EOO (ASCII) Coverage
  • Arc/Info Generate
  • Atlas BNA
  • AutoCAD DXF
  • Comma Separated Value (.csv)
  • EDIGEO
  • GeoJSON
  • GeoconceptExport
  • Generic Mapping Tools ASCII
  • GPSTrackMaker (.gtm, .gtz)
  • Hydrographic Transfer Format
  • Idrisi Vector (.VCT)
  • Mapinfo File
  • Microstation DGN
  • OpenAir
  • PCI Geomatics Database File
  • Planetary Data Systems TABLE
  • PostgreSQL SQL dump
  • EPIInfo .REC
  • S-57 (ENC)
  • SDTS
  • SEG-P1 and UKOOA P1/90
  • SEG-Y
  • Speacial Usa Airspace (SUA)
  • UK National Transfer Format (NTF)
  • US Cencus TIGER/Line
  • VRT - Virtual Datasource
  • X-PLane/Flightgear aeronatutical data
  • USGS SDTS DLG
  • USGS "Optional" DLG
  • DCW - Digital Chart of the World
  • GSHHS - Global Self-consistent, Hierarchical, High-resolution Shoreline
  • NOAA/NGDC Coastline Extractor
  • US Census TIGER Boundary

Besides the custom data loaders that will import data in the listed formats, you can import a variety of simple geospatial data types using Igor Pro's various general-purpose text and binary data import operations.

Data Display and Analysis

Monterey Subrmarine Canyon Profile
Monterey Submarine Canyon Profile

In addition to the specialized geospatial data import and analysis tools, Igor Pro includes a variety of built-in operations that may be useful for displaying and analyzing geospatial data. Most useful may be some of the image analysis operations, such as ImageLineProfile and ImageTransform. For examples of how ImageLineProfile might be used, the image above shows the creation of a profile for the Monterey Canyon and the image below shows a finished and greatly modified profile of Crater Lake.

Bathymetry of Crater Lake, Oregon
Bathymetry of Crater Lake, Oregon

You can create contour plots of 2D raster data sets or project vector data using various standard map projections (orthographic, stereographic, gnomonic, general perspective, Lambert equal area, equidistant, Mercator, transverse Mercator, and Albers equal area). Using the IgorGIS XOP you can project raster or vector data to/from any spatial reference expressed in OGC Well Known Text. The Spatial Reference website provides thousands of spatial references, all available in OGC Well Known Text.

Lambert World Projection
Lambert World Projection

You can display vector data as you would any other XY data set. In Igor Pro graphs you have control over the line width, color, patterns, etc. You can display 2D DEM data with all of the flexibility you have with normal 2D graphs.

With the Gizmo visualization tool you can construct 3D models of your DEM data to show perspective views with contours, lighting, shading, and texture maps. Two examples of the Mt. St. Helens volcano in Washington state are included in our sample image gallery. One is a perspective view of earthquakes beneath the volcano and another is an animation of the volcano before and after it's 1980 eruption.