MICRODEM GIS Course Lab 1

With no data open in MICRODEM, go to File, Annapolis GIS data sampler.  If the 900 MB zipped data set is not present, it will be downloaded.  It will set a number of defaults to directories with this data, which will go into c:\mapdata\annapolis_data

We will not use all this data, but it is easily available for anyone who wants local data.

Basics of running MICRODEM and how to perform common operations.

In this lab we will look at the different types of data manipulated  in GIS software, combine several layers on a single map, and export  maps to Google Earth.  The goals of the lab are:

1. Understand the basic map operations in the GIS program
2. Introduce the different types of data available in a GIS.  The options available in the GIS program depend on the type of data.
3. Understand how the KISS principle used in the design of Google Earth affects its operations.

We will come back to many of the concepts touched on in this lab, in much more detail, but want to see an overview of what GIS can do before we get down in the details.

Deliverables in Blackboard.

In a  singleWord document and a single KMZ file.  You will correctly label the figures (caption below) and tables (caption above).  The figures will come after the first reference to them in the text.  Make this a discussion (well written); do not make it a question/answer.  The cut and pasted questions should not be in the deliverable Word file.

• How can you differentiate the UTM grid and the lat/long graticule from their geometric properties?  How are they different on the maps with the DEM, the CONED,  and the NLCD?
• Overlay the TIGER edges on the three NED DEMs.  Explain how the road network differs in the three maps, and why you think this is the case.  You might also consider what happens when you zoom in, or blow up the maps.  This could be a table.
• Get a map with all the OSM layers showing point, line, and area vector overlays.  Comment on what the different layer geometries mean.
• Get a map showing the locations of all the "schools" from the gazetteer in Anne Arundel County.  Show it on the DEM, use the standard school icon, and perform an export to Google Earth.  Comment on what is counted as a "school" in this database.
• Comment on the distribution of buildings in the OSM data for this region, looking especially the regions around Chesapeake High School and Severna Park High School.
• Discuss how the point cloud helps to visualize the terrain.

In a single KMZ file.  This will be organized and labeled so your audience can turn the layers on and off.  The labels should mean something to a real user, and not just to a GIS geek.

• Anne Arundel County schools, with school symbol icons.
• Anne Arundel County churches, with appropriate symbols.

In a GIS program, there are almost always multiple ways to perform an action.  These instructions will generally give you one way, the links will show you others.

MICRODEM allows you to open multiple map windows at the same time, which some other other GIS programs will not.  Both MICRODEM and other programs allow you to stack data sets in layers to build up a complex map, and rapidly change the display.  Plotting order is important; the top layer may obscure layers under it.

• New DEM to open a raster data set called a Digital Elevation Model (DEM).  Open all three of the NED files which cover Annapolis.  Note they are all approximately the size file size (9-17 MB), but cover regions of very different sizes which you can see from the scalebars.  The data sets have missing data, in the water, but the effect is not uniform.
  • Change display parameter.  Change the display settings when you make this change, or right click on the map and select the choice for the current display option such as Elevation, Slope, or Reflectance
  • Grid: put up both a UTM grid and a lat/long graticule.  You probably want to adjust the color/line width so you understand them; normally you would only show one, and use thin black lines.  Note:
    • Shapes of polygons (are they square or rectangular)?
    • Are they parallel to the edges of the map?
    • Are they parallel to each other?
  • Information on the map to see if the map data had to be blown up, or reduced to fit on screen, and the data resolution.  You need to keep track of the real resolution of the data, and how much of it you are seeing on screen, before you make hasty decisions about quality.  Many data sets have many times more data than will fit on screen.
  • Copy to clipboard to export a map.  If this is not on the toolbar, use the right click popup menu, or the File menu.  You have the choice of a quick export, or a cartographically pretty map with a Grid/graticule. You want just the map in your reports, and not the window.
  •     Map zooming.  For large maps, consider Subset (graphical) & zoom instead of blowing up so you do not wind up with unusable large maps.
  • To open the OpenStreetMap (OSM) data, use the menu choice Database, Load OSM overlay, and select the directory.  This will open a series of databases, and use intelligent display options in terms of symbolization and what shows on the map.  If you open as regular databases, you may have to play with the display options, and it might be slow to draw and then completely cover the map.
  • Database to overlay the TIGER, and gazetteer.  The program will recognize the TIGER as an important standard data set, and use appropriate symbolization (which you can modify if desired).  This is different than the Open database without map DB button on the main toolbar, which just opens a database for analysis without map interactions.  Table display options, in particular:
    • Filter: restrict display to only  records that meet specified criteria. You will need to use the wildcard symbol ("*" for MICRODEM's database, but can be different in other programs).
    • Plot: plot selected records on the map.  You can control the symbolization.  The best choices will be: Color code by database field, or Icons
    • Stats: perform statistical operations (not map based) on the database. 
    • ID: identify records on associated map by double clicking. Same function as ID button on map toolbar.
    • Map query:  Geographically filters data; restriction will remain in effect until removed. You will most often use a rectangular box.
    • Frequency table which you can sort from most to least common.
    • To get gazetteer schools and churches:
      • This will require a three part filter: for the type of structure, for the state, and the county.  (Even though this database is for Maryland, it has some records listed for other states, since each feature, even the Potomac River which passes through multiple states and DC, is listed for a single point in one of the states).
      • If you export this database subset, Report button for the database table form, then DBF file, it will give you the greatest flexibility and require minimal disk space.  GIS work usually involves creating a numbe of new data sets, and you have to balance creating them on the fly as needed, or saving them after first creation, and being able to find them (GIS Project Management).
    • To find Eastport Elementary School (or another feature):
      • Filter with something Like "Eastport Elementary*"
      • Search, by Double clicking on field name and picking "Find"
  • Table of contents to control display of databases on the map, to change the plot order, and to plot/hide layers.
• New Landcover map (NLCD).  You want the TIF file; if you do not see the extensions, tell Windows to show file extensions.  This is an image, which is fundamentally different from a DEM and has different display options and characteristics, and different choices in the menus.
  • Grid: How is this map's grid and graticule different from the DEMs?
• LIDAR Point clouds on the map toolbar for the one-ninth second NED DEM.
  
  • Turn the NED display to a grayscale reflectance map.
  • Pick the directory with the LAS files.  The 2011 data set covers a larger area and should be your choice.
  • Insure the display is set to elevation, and adjust the range to 0-30 m.  Then display the points on the map.
  • Subset (graphical) & zoom to an interesting building or group of buildings.
  • Look at that small subset OpenLG view controls.  Bancroft Hall, the swing bridge over Weems Creek, or the State House are good examples.

You will need to use the following additional techniques:

Legends:

• For the DEM map, you can put a legend on with the Legends/marginalia option by right clicking.  You can pick where to put it, which should not be in the same location as the scalebar.
• All of these maps should have a scalebar with the Legends/marginalia option by right clicking. 
• For the database, there are several options:
  • Legends/marginalia option by right clicking will work if the plot is of a numeric field.
  • For Color code by DB field, you can get a legend, which will frequently appear in a separate window because it can be very large.  You can copy that to the clipboard, and either put it beside your map inside Paint or paste it onto the map (right click, paste from clipboard lets you drag to whatever region of the map does not have any important content) .  This will always be the case for a string field.

Icons

KML and Google Earth

• KML database export for Google earth.  For this lab you can make a quick export (or multiple exports with different filters) from the Report button for the database table form.  This provides some of the functionality of the database.  To get the icons you might need to use the deliberate export.  The deliberate output provides a lot of flexibility to customize the export.
• KML export map image.  This creates a "dumb picture", but it will be in the correct location.
• Clean up KML exports and save KML/KMZ within Google Earth.  This will make the results much more usable,  which is your job when you make a map.

Verify what is at a location:

• WMS Maps.  This must be a fairly small area in the US, but you can get color aerial imagery.  You must pick the state you want.
• Right click, Export,
  • KML export, which will place the map on Google Earth, and let you see the Google imagery.
  • Location to Google Maps
  • USGS data, TNM viewer: gets USGS color imagery

Suggestions added 8/26:

You are not expected to make your first maps perfect; the goals of this lab are given above, and we are learning by doing.  Hopefully with each lab the process will get easier, and your maps will get better.  If you would like to improve your maps, try the following:

• The missing data, holes, or voids in the NED are very annoying.  You could try the following:
  • Edit, DEM Holes, Missing data to sea level.  This will not work in every case (when you are not near sea level), but does here.  After you do this, you can File, Save DEM, "Entire DEM, MD DEM".  Then open the new DEM in the future.
  • Go to Options, Import/Export, and pick Missing Values to sea level.  This will not work in every case, but does here.You do not need to save the DEM, since this will happen every time you load the DEM.
• TIGER.  There is an option on the Manage Overlays choice to add the TIGER data.  This requires that you place the data in the correct location, and index it.  For now, unless you want to deal with a number of details, just open with the database button.
• Load project (after you have saved it with File, Save Project) will let you restore most of your work.  There are a number of caveats to making this work, and it will generally not save you much work. 

Last revision 8/20/2018