Finding Your "Type"

One of the common questions I after folks start working with Feature Data Object connections in AutoCAD Map 3D is how to use interesting linetypes in their maps. To add linetypes to FDO-connected data sources, select the ellipses next to the Thematic Rule in question, and the Style Line dialog box opens. There you can select the thickness, color and pattern for the line.


The pattern selection provides a set of linetypes – not the AutoCAD Linetypes (there is no direct way for users to modify this list, although it can be programmatically edited – more on this another time). This will provide a number of options and style combinations.
You can also stack line patterns to create more complex styles. For example, many road maps will use a red line with black borders for a highway, sometimes with a back center line or dashed line to show divided highways. This can be modeled by using several lines patterns overlying each other.
To do this, select the composite lines option. The Style Line dialog box will then expand to add a composite style box where you can add multiple line components.




To make the example highway style, add 2 new lines by clicking the New button at the top of the composite box. Select the line at the bottom, change it to a .2 cm thickness at black with a continuous pattern. Change the middle line in the box to a continuous red line with a width of .15 cm. Change the top line to a black line with a dashed pattern at a .1 cm thickness. The resulting line style will be apply to this theme rule throughout the drawing.

You can have different composite lines for each theme rule, allowing fairly complex maps. Combine these with some annotation patterns and you can make maps that look like the standard road maps from various publishers.

Happy GIS Day! Here's some Arizona GIS Data Sites

Today is National GIS Day! (at least it was when I originally posted it)

CADsoft Consulting's CAD Camp 2009 is well underway. We had a very successful Architectural/BIM day yesterday, and the Civil day is in full swing. Tomorrow will be the Geospatial Day (so it doesn't interfere with any GIS Day activities). This morning we've had a presentation from Autodesk's Civil 3D maven, Lucy Kuhns, and our own Ron Coulliard is doing a workshop on grading as I type. During Lucy's presentation, I was asked about local Arizona GIS data, so I promides to share some of the sites I use/am aware of. The list is by no means exhaustive, and there's some dupplication within the sites, but here you go anyway. I'll continue to identify sites I run across in the future. If you've got some good ones you want to share, add them to the comments or email to me and I'll add them to the list.

GIS Data Sites for Arizona

Arizona State Cartographer's Office
They maintain the Arizona GeoServer, with aerial photos and statewide features served through web mapping services (WMS) and web feature services (WFS). They also maintin links to other data sources throughout the state

The AGIC (Arizona Geographic Information Council) GeoData Portal
AGIC is a state sponsored group working with GIS across the state. They sponsor an annual GIS educational conference every year. We just finished the 2009 conference in Tucson. There was great attendance. I presented 3 hands on worksops this year. They have County boundaries, tribal boundaries, cities, wilderness areas, political boundaries, voting districts, school districts, census information, environmental and natural resource data, interstates and roads

US Fish and Wildlife
USFW maintains larger scale data sets covering National Wetlands Inventory and area boundaries

U of A Library
The U of A Libraries maintains the Arizona Electronic Atlas and the Arizona Regional Image Archive (ARIA) as well as links to other data sites

ASU
The ASU Libraries also has spatial data and links available

ADEQ
Arizona Department of Environmental Quality (ADEQ) has water quality data, surface, drinking and groundwater

Local division sites

Maricopa County
The County Assessor's Office GIS Department maintains data for the county including parcels, detailed topographic data, floodplains, and survey network.

Pima County
Pima County is really one of the long runners in GIS. They have had data available for as long as anyone in the state. They maintain over 273 data layers in ESRI shape files as well as landbase section maps in AutoCAD format.

City of Phoenix
Phoenix has an extensive collection of GIS data. They have Engineering Quarter-Section maps in DXF format CAD files

Nationally-based sites

US Forest Service

FEMA
The Federal Emergency Management Agency maintains flood hazard data sets which are available as GIS data sets or through a Web Mapping Service (WMS)

NSGIC
The National States Geographic Information Council maintains an inventory of data and its currency in the Ramona GIS Inventory. Arizona's page is here:

Natural Resources Conservation Service (NRCS)
The NRCS maintains the Soil Data Mart with soil data available by state. They also collect other data such as water supply and snowpack

United States Geological Servey (USGS)
The USGS maintains large scale data sets for the US. They have digitial orthoquads and photos, land cover, elevation model and other data sets.

US Census Bureau
The Census maintains census and popluation data for the US

United States Department of Agriculture

USDA has Forest Coverage

Geography Network
The Geography Network maintains various spatial data sets for the US

ESRI Geoportal Extension
ESRI has a beta site with downloadable GIS data

National Center for Atmospheric Research
Atmospheric data for the US


New Mexico

Lucy Kuhns mentioned the New Mexico Resource GIS program site. Here's the link:
http://rgis.unm.edu/

Losing Your Religion: Interoperability with AutoCAD Map 3D and ESRI - Part 1

I’ve been speaking at conferences for several years about CAD and GIS interoperability. It’s one of those topics where there’s a lot of interest and a lot of misinformation. Or at least, it seems to be much more difficult than it really is. I’ve been moving data between both systems for years, with very few real challenges. What I’ve found, is that the real issue is not the technical aspect of moving data back and forth, but the differences in how the software is generally used. AutoCAD (and other CAD systems) are primarily used for doing design work, and GIS (ostensibly ESRI, but it could be any GIS system) is primarily used for managing as-built facilities and systems. The real challenges are working between the design and as-built management processes. In other words, the issue isn’t CAD to GIS, the issue is Design to As-Built.

I’m going to make several blogs here in a series of the issues and some methods to make the process easier. This first post, I’m going to discuss the a bit about the similarities in the technologies. Following that, I’ll be posting on the differences, barriers, myths, and other issues involved.

Both AutoCAD and ESRI are built on basic primitive elements that are combined to create representations of real objects. Both systems include:

Points - a representation of a single location. It could represent a physical object such as a pole, manhole or brass cap in the ground, or it could be a non-physical point, such as a crime scene location or the corner of a property line. In any case, the systems both record a coordinate consisting of an X and a Y and possible a Z (if elevations are being included). The X and Y value could represent any projection or coordinate system, such as degrees of latitude and longitude or northings and eastings from a state plane.



Lines – a representation of of a connected set of coordinate pairs. Every line is going to have a start point defined by X, Y and/or Z, and and end point defined by an X, Y and/or Z. It could represent the centerline of a road, the edge of a building, or a buried pipe.



The line may be defined the system by coordinate pairs, such as point A and point B, or it could have the actual coordinate values in the line definition, such as this example from AutoCAD (a listing of a line – the start point is the set of parenthesis with the 10 X Y Z, and the end point is 11 X Y Z):



In some cases, for example, ESRI, the actual coordinates of the line are stored within an object “envelope”, which is a rectagle enclosing the object.



Polygons – a representation of an area. It could be a representation of a parcel, a building footprint, or an animal migratory zone. It is defined by lines and so by a series of bounding coordinates. Generally, in vector systems (save that discussion for another time), polygons are defined by their boundaries. They could be defined by groups of lines, or it could have the coordinate values built into the definition, simlar to the lines (as shown above).



In ESRI, the coordinate pairs are contained in an envelope bounding the entire object:



Attributes - data associated with an object. Associated data could be an identification number, a name, a description of the object, the color, size, diameter, etc. This is what turns a simple point, line or polygon into a representation of a fire hydrant, electric line or county. Attributes may be stored and linked to the object in a myriad of methods. It could be based on a common identifier stored in the object definition and the attribute list, as in a primary-foreign key relationship, or the definition of the object may be created to include certain atribute sets intrinsically. In some cases there may be a mixture of methods. For example, in AutoCAD, objects have intrinsic attributes (such as blocks attributes), extended entity data (attribute values associted to an individual object), or object data (data tables stored internally in the drawing and linked to objects). Additionally, both systems include methods to link objects to externally associated databases to extens the attributes of an object.



Understanding these similarities is key to understanding how to integrate these two systems. The next post, I’ll discuss the primary differences between the two.