class: title-slide, center, middle # Computational Archaeology ## 08 - GIS I & II ### Martin Hinz #### Institut für Archäologische Wissenschaften, Universität Bern 13/11/19 & 20/11/19 --- ## GIS [1] .pull-left[ > A geographic information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geographic data. - Wikipedia ] .pull-right[  ] --- ## GIS [2]  --- ## What can we do with a GIS?  --- ## QGIS - a free and open source GIS software - https://www.qgis.org/ - If you not have already installed QGIS, please do now! .center[  ] .right[  ] --- ## Raster vs. Vector .pull-left[  ] .pull-right[  ] --- ## Lat/long system .pull-left[ Lat/long system measures angles on spherical surfaces * 60º east of PM * 55º north of equator * Lat/long values are NOT Cartesian (X, Y) coordinates * constant angular deviations do not have constant distance deviations * 1° of longitude at the equator ≠ 1° of longitude near the poles ] .pull-right[  ] --- ## Coordinate Systems .pull-left[ - Features on spherical surfaces are not easy to measure - Features on planes are easy to measure and calculate - distance - angle - area - Coordinate systems provide a measurement framework ] .pull-right[  ] --- ## Coordinate Systems and Projection [1] .pull-left[  ] .pull-right[  ] --- ## Coordinate Systems and Projection [2] .pull-left[ - an imaginary light is “projected” onto a “developable surface” - a variety of different projection models exist - Map projections always introduce error and distortion ] .pull-right[  ] --- ## UTM .pull-left[ Universal Transverse Mercator (UTM) - Based on the Transverse Mercator projection - 60 zones (each 6° wide) - false eastings - Y-0 set at south pole or equator ] .pull-right[  ] --- ## Schweizer Landeskoordinaten .pull-left[ - a geographic coordinate system used in Switzerland for maps and surveying by the Swiss Federal Office of Topography (Swisstopo) - The map projection used is Oblique Mercator on an 1841 Bessel ellipsoid. - All coordinates are always positive, since Switzerland is located in the 1st quadrant of the coordinate system. ] .pull-right[  ] --- ## Datums and Ellipsoids .pull-left[ - The earth is essentially a potatoe... - Ellipsoids are geometric estimations of the shape of the earth with more or less accurary - a datum is a system that allows us to place a coordinate system on the earth’s surface based on a specific ellipsoid - examples: - WGS84 (Lat/Lng, UTM) - Bessel 1841 (Schweizer Landeskoordinaten) ] .pull-right[  ] --- ## Georeferencing   Download original file: [miskovice_overview.png](miskovice_overview.png) Background openstreetmap: https://tile.openstreetmap.org/{z}/{x}/{y}.png coordinate system wgs84/pseudo-mercator (EPSG: 3857) --- ## Digitising download the georeferenced files: - [miskovice_overview_modified.tif](miskovice_overview_modified.tif) - [miskovice_a-d_modified.tif](miskovice_a-d_modified.tif) - [miskovice_e_modified.tif](miskovice_e_modified.tif) - [miskovice_f_modified.tif](miskovice_f_modified.tif) Make a new shape layer (points) Start digitising and save layer --- ## Changing design load shape file(s): - [miskovice_graves_shp.zip](miskovice_graves_shp.zip) - extract - Layer > Add Layer > Add Vector Layer right click on layer > Properties > Symbology --- ## Heatmap right click on layer > Properties > Symbology > Heatmap --- ## Thematic map (1:1 Relationship) - import csv-file (add Delimited Text layer) [miskovice_graves_data.csv](miskovice_graves_data.csv) - join attribute table with geolocations - visualise (via symbology) --- ## Thematic map (1:m Relationship) - import csv-file (add Delimited Text layer) [miskovice_types_per_graves.csv](miskovice_types_per_graves.csv) - create virtual layer - sql join - `select * from miskovice_graves left join miskovice_types_per_graves on miskovice_graves.id == miskovice_types_per_graves.grave_number` - visualise (via symbology) --- ## Exporting right click on layer > Export > Save features as... - shp - csv - geometry ('AS_XY') --- ## Importing Layer > Add Layer > Add Delimited Text Layer --- ## Exporting maps Project > New print Layout - add map - add north arrow - add scalebar - export as Image - export as PDF --- class: inverse, middle, center # Any questions? .footnote[ .right[ .tiny[ You might find the course material (including the presentations) at https://github.com/MartinHinz/ca_hs_2019 You can see the rendered presentations at http://martinhinz.github.io/ca_hs_2019 You can contact me at <a href="mailto:martin.hinz@iaw.unibe.ch">martin.hinz@iaw.unibe.ch</a> Sources for the slides: * Steiniger 2009, Free and Open Source Desktop GIS Projects and Software * Briggs 2019, GIS Fundamentals * Leeds, Raster GIS * Lawler/Schiess 2010, Projections and Coordinate Systems ] ] ]