January 25, 2008

Georeferencing and the Road to Oklahoma

Basketball season is in full swing with multiple games most weekends. This year we’re fielding two teams a JV and a Varsity team. Like last year our varsity team still includes all underclassmen one 11th grader, three 9th graders and an 8th grader. In the first round of league games the girls remain undefeated. This year the girls are attending both the California state tournament and the National tournament in Oklahoma as an 18 and under team (last year they won the California tournament as a 14 and under team).

Several different divisions will be hosted at the National homeschool event. Our girls will be competing in the 18 and under all-comers group against various teams from around the country. There is a higher division we will not play, seeded from regional tournaments which field teams more at the AAU club level of play. Regardless we will be stretching out from our local athletics organization to a bigger collective enterprise. We will likely participate in contests against teams that out match us in age, skill, speed, strength and experience. This is nothing new for the girls; it has been true for these girls all the years I have coached so far, albeit now they will set their sights on a higher level of play. There they will be integrated into the bigger picture: some of the athletes competing in Oklahoma will go on to play basketball at major universities.

Often a CAD file is drawn in a local coordinate system. When the drawing depicts spatial information it can be drawn accurately without having to be tied into a global coordinate system. However there may come a time when that drawing needs to participate at a higher level and be brought together in a mapping context with data from many different sources. Tools in ArcMap can quickly reposition a CAD file and integrate it into the bigger picture without modifying the CAD file.

Before I start I’ll need to know where two points on the CAD file should match up to two points in the map. I use the Georeferencing toolbar in ArcMap. There are several different tools on the toolbar to support different workflows. Here is how I like to use it. First I load the CAD drawing and make sure one of the CAD feature layers are listed in the drop down of the georeferencing toolbar. (Doesn’t matter which CAD layer POINT, POLYLINE, ANNOTATION, POLYGON, etc...) Next I zoom to roughly the place on the map were the CAD drawing is to end up. I don’t bother zooming out to the position of the CAD file, instead I use the fit to display tool on the menu to quickly get the CAD file in the map frame so that I can pick control points. For accurate placement I will turn on my ArcMap snapping so I can pick control points exactly based on existing geometry. If the CAD file needs to be rotated I might use the rotate tool to get the drawing closer to its final position… then only if it makes it easier to pick the points. I sometimes use the interactive scaling tool for the same reason. Most times I just fit to display and pick the four control points and I’m done. I select the update georeferencing option and the tool creates a .WLD file for me that will be read from now on to put my CAD file in the right place.

Now the coordinates are always adjusted into this position. At this time I can choose a coordinate system for my CAD drawing so that if I ever need project its coordinates along with the map or during some geoprocessing operation it will work.

January 09, 2008

BIM: What’s Cooking?

I took some time off over Christmas break, and at least from a food perspective the vacation was characterized by diverse types of bread making/eating. I made cream puffs, English muffins, bagels, pizza dough, and cinnamon rolls from scratch. These are different types of bread with sometimes very similar ingredients. Muffins, puffs, crust, rolls, all different words for essentially the same thing… bread. Arguably these required vastly different workflows for different food applications and sometime unique ingredients. I really want to make some more English muffins; I never thought they would be so easy to make, yum.

I attended a recent BIM Conference in DC. As an active listener at BIM conferences I am looking at how existing GIS applications that work with buildings are keeping pace with the emerging technologies and more importantly the emerging expectations of what may be called BIM.

For many BIM continues to hold the expectation of an over-arching technology where the building information models and their explicit definitions are the key to making better decisions for an ever-growing and seemingly unlimited list of applications.

I have a growing appreciation for the efforts of organizations promoting standards and starting conversations that can help put scope and context to efforts in the building industry to reduce waste and promote better practices. The standards themselves are not an information system, but they do serve as a powerful means to define the semantics of how to ask better questions and the context for new information systems applications. They challenge the building industry to consider new ways to improve how things are done.

I heard it said a number of times at this conference and at other conferences that workflows rooted in the trade guilds of antiquity, frustrate the modernization of the building industry. These hindrances are so strong that it was said productivity of designing and constructing buildings in the modern age has actually decreased rather than increased! Other industries such as manufacturing it is said have greatly increased their productivity through modernization, integration and automation. Messages directed to conference attendees suggest that if they do not heed the warnings, the building industry could be categorically replaced by what I will call “building manufactures”.

Consider a company that designs and builds airplanes or cruise ships… what software and workflows do they use to plan, design, construct, and build their structures? A cruise ship is essentially a city, with housing, shopping malls, security, restaurants, parks, sanitation systems, electrical production and distribution systems… take off the propellers and remove the requirement that it needs to float and what do you have…? Perhaps there are useful solutions that already exist in a number of places in slightly different forms.

GIS seems to be well positioned to benefit from the efforts of BIM data standards development as another well or poorly structured data source that can benefit from geospatial visualization, computing and management. If you consider a building can be a geographic feature then the GIS is a fine BIS (Building Information System) for many existing applications related to site selection, planning, operations and management of buildings. Assuming you have the tools to read/write and analyze the data for a given information system application there is nothing special about a building that disqualifies it as just another GIS system of data. As I see it right now GIS excels with geographic features to visualize, compute and manage all different types information system applications.
You can break-down the pieces of a building into individual features or ingredients. When you consider a BIM as a source of content, much like a CAD file is now only better structured; it becomes another useful source of data you can manage in an information system. GIS is not a BIM in any sense, any more than a cream puff is like an English muffin. I can cook up something worth while by using the ingredients in the BIM along with other spatial data in my geographic information system. How and what I mix together and what I leave behind on the shelf greatly depends on what I’m making be it a facilities management application or emergency response application, etc... In the case of the English muffin it was Eggs Benedict, and for the cream puffs it was sausage and cream cheese filled lunch pastries.
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