GG5019 An Introduction to Geographical Information Technology and GIS Geographical Information Systems and Geospatial Data Analysis David R. Green G12 –

Objectives Lecture 3 Objective GIS functionality GIS Data Sources File Sizes GIS Data Formats

GIS Functionality Display (Table/Map) Visualise Pan Zoom (+/-) Search Information Label

GIS Functionality Convert to Shapefile Select Subset Project Measure (Distance/Area) Buffer Query

GIS Functionality Scripts

GIS Functionality Extensions GeoProcessing (Wizard) Spatial Analyst (Proximity, Map Calculator, Statistics) 3D Analyst (3D Visualisation) Image Analyst (aerial photography / satellite imagery Animal Movement - XTools Beach Tools /Oceanographic Analyst

Data Sources Virtually any source and type of data can be input to a GIS providing it has a location (X-Y, Longitude-Latitude, Postcode or any other locational position) Both Analog and Digital data sources: Traditional Maps (cartography) - digitising Paper documents e.g. text files - scanning Pictures (35mm camera) - digital / scanning CAD drawings (engineering) - digital / digitising / scanning Data Loggers (field data: temperature, soil moisture, contamination) - analog /digital Questionnaires - digital / analog Spreadheets and Databases - digital Remote Sensing (including aerial photography and satellite imagery) - digital / scanning Global Positioning Systems (GPS) - digital Digital Camera and Video - digital Multimedia GIS - most including ArcView and Idrisi are Multimedia in the sense that they can handle any type and source of data

Filesize Calculations Scanners (black and white and colour) Size of image to scan e.g. aerial photograph Spatial sampling: dots per inch (dpi) or bits per inch (bpi) Grey Scale/Colour depth: 2bit, 4bit, 8bit, 16bit, 32bit File formats: BMP, GIF, TIF, JPG, compressed etc…. Bits, Bytes………………. Mb, Gb, Tb True Colour Aerial Photograph: e.g. (9x300dpi) x (9x300dpi) x 8bit = ?? Mb (approximate) Colour depth 128 dpi Image (x) Image (y)

Online Data Sources UK – Vector (and Raster) Map Data Ordnance Survey: Edina Digimap: UK Borders: English Nature: nature.org.uk/pubs/gis/tech_ds.htmhttp:// nature.org.uk/pubs/gis/tech_ds.htm MAGIC:

Data Formats Vector and Raster data often stored within GIS software in different ways: data formats (the way in which data is arranged in the computer file) Different GIS have their own data formats for vector and raster data ArcView, for example, uses the.shp shape format for Feature (or map) data The shape format has become almost (but not completely!) a vector standard It can be read (or imported) by most GIS software e.g. MapInfo Usually vector formats are accompanied by additional files and formats that contain additional information about or data associated with the vector format

Data Formats/File Extensions These files and file formats in ArcView come together with the.shp (map) They are:.shx (header file);.dbf (database file containing the associated table) (sometimes.sbx and.sbn also) Note: must be kept together whenever saved to disk or CD Image or Raster files come in many formats. The most common for GIS are:.TIF (Tagged Image File);.JPG (JPEG - Joint Expert Photographic Group; and GeoTIFF (a.TIF with map co-ordinates) JPGs (or JPEGs) can also have co-ordinates in a WORLD FILE (text file): if you remember the Nightphoto image had a Worldfile with it. World Files contain reference co-ordinates. These files can be opened and viewed in a text editor such as MS Wordpad or Notepad) Special format Image files are usually associated with special software e.g. Erdas Imagine uses a special format.IMG (not the same as Idrisis.IMG though!)

Data Formats/File Extensions These files and file formats in ArcView come together with the.shp (map) They are:.shx (header file);.dbf (database file containing the associated table) (sometimes.sbx and.sbn also) Note: must be kept together whenever saved to disk or CD Image or Raster files come in many formats. The most common for GIS are:.TIF (Tagged Image File);.JPG (JPEG - Joint Expert Photographic Group; and GeoTIFF (a.TIF with map co-ordinates) JPGs (or JPEGs) can also have co-ordinates in a WORLD FILE (text file. World Files contain reference co-ordinates. These files can be opened and viewed in a text editor such as MS Wordpad or Notepad) Special format Image files are usually associated with special software e.g. Erdas Imagine uses a special format.IMG (not the same as Idrisis.IMG though!)

Data Formats / File Extensions Many other data formats other than map and images are also supported by most GIS Grid files (often as ASCII.TXT (textfiles) (American Standard Code for Information Interchange Spreadsheets and Databases (.XLS - MS-Excel;.DBF - DBASE;.DBF - MS-Access) Also, NOTE in the UK, the Ordnance Survey (OS) uses its own format:.NTF (National Transfer Format). Few GIS can read this directly. ESRIs Map Manager (in the Geography Folder) must be used to convert OS map files to.SHP for input to ArcView OS Mastermap data comes in the GML (Geography Markup Language) format

Data Formats / File Extensions The Image formats are accessed in ArcView by switching on ArcView Extensions: JPG, TIF and IMG and changing from Feature data to Image Data In other software you may need to use IMPORT functions/utilities There are many other image file formats that are not directly used in GIS e.g..BMP,.GIF,.PNG If image files do not come in the correct format for a GIS to use, then you may have to use UTILITY software to convert to the desired format e.g. Paintshop Pro, Fireworks CAD files can also be imported: the most common is the Data Exchange Format (.DXF) ArcView (and other GIS) can use DXF by switching on the.DXF extension

Online Data Sources UK – Raster Map Data Landmap: Landsat: Landsat: Landsat: SPOT: ASTER: