Archive for March, 2008

Did you know you can copy and paste objects from one OpenSpace layer to another in XMap GIS Editor or Enterprise?

March 10, 2008

This feature is useful for combining or merging the contents of two or more layers.

  1. Choose the layer containing the objects you want to copy from the Active Layer list on the toolbar.
  2. Use the Edit tool in the toolbar to select the objects that you want to transfer. You can select multiple objects by holding down the SHIFT key, or by performing a sweep select. Note that the Edit tool only becomes active for layers that are checked on in the Workspace.
  3. Right-click the selected objects and click Copy.
  4. Select the target layer from the Active Layer list.
  5. Right-click anywhere on the map and click Paste. The pasted objects will appear at the same location as they were in the source layer. 

If the attribute fields are the same in both layers, all attribute values are copied. Attribute fields from the source layer that are not included in the target layer are removed.

Understanding the Differences between the Draw and GIS Tabs in XMap

March 10, 2008

Long time users of DeLorme software will be familiar with the functionally of the Draw tab. Since the earliest versions of Street Atlas USA, draw tools have allowed users to annotate to the map and to create their own map features. Today the Draw tab is a central component in all DeLorme software titles, both consumer and professional.

forest_stands.jpgFor users of XMap GIS Editor or Enterprise, the importance of the Draw tab has been somewhat diminished with the development of the GIS functionality. While both tools allow points, lines, and polygons to be added to the map, the GIS tab includes the ability to add attributes to these objects. This allows you to develop and manage an extensive database of information, which is tagged to the appropriate location.

As an example, let’s compare the use of the Draw and GIS tools to create polygons for delineating forest stands. In either case, polygons can be easily drawn, the color of the objects can be adjusted as needed, and the geometric characteristics can be edited. Both functions allow coordinate geometry input to create map objects with a high level of precision, and both can be overlaid on any base map or imagery layer. On the surface, therefore, it is impossible to distinguish a polygon created in the Draw tab from one created in the GIS tab.

Taking this hypothetical project a step further, it is likely that the process of mapping the forest stands also involves collecting relevant information about the areas in question and perhaps cataloging such data as the types of species present, the date of the survey, and much more. Unfortunately the Draw tab does not offer the option of adding such attribution to the objects on the map. When using the GIS tab, however, a limitless array of attribute fields can be appended to each map feature and the data they contain can be used to reveal spatial patterns in the distribution of data through a classification process. This function of the GIS tab thematically adjusts the visible characteristics of the objects on the map to reflect the variations in the selected attribution. Furthermore, the Query feature of the GIS tab can be used to quickly locate an object or group of objects based on its attribution or based on its spatial relationship to other map objects. Finally, the GIS tab can used to import and overlay data from third party sources, such as shapefiles or CAD files, which can help create a more complete picture of the area being studied.

With the availability of powerful data mapping tools in the GIS tab, what role does the Draw tab play for XMap users?

  • Even in advanced GIS applications, it is often useful to add a simple text label or a MapNote, which is easily done using the Draw tab.
  • When exchanging data with a GPS receiver, such as the Earthmate GPS PN-20, the Draw tab is used to manage downloaded waypoint and track layers before they are converted into GIS layers, and to create waypoints and tracks to be sent to the PN-20.
  • When employing the data synchronization functionality between XMap GIS Enterprise and XMap Professional, the redlining functionality uses the draw tools to communicate field-collected notes and other annotation with the data administrator.
  • The Draw tab can be used to create routable roads and trails not present in DeLorme’s base maps. 

For these reasons, the Draw tab is still an important feature in the XMap product suite; however, for creating points, lines, or polygons on the map, it is the GIS functionality that provides the more powerful set of data management tools.

Where can I find data to import into XMap?

March 10, 2008

If you have visited the XMap Web site, you should have seen a selection of screenshots that were created for the purpose of illustrating a diverse variety of applications for the software. While these screenshots include examples of some of the datasets that DeLorme offers for use with XMap, the majority focus on data that was either developed using XMap’s data creation tools or that was integrated from third-party data sources. A commonly asked question is, “From where does this third-party data originate?”

eagle_nests.jpgThere are countless sources of spatial data in both vector and raster format, much of which can be freely downloaded from local, state, regional, or national government Web sites or sometimes from educational institutions. Try typing “GIS Data” followed by a geographic area of interest into a Web search tool and you will often uncover libraries of data that will meet your needs.

For instance, here in Maine, the state-level GeoLibrary Board maintains and distributes almost 150 different data layers in vector format — everything from hospital locations to eagle nesting sites. Depending on the type of data, shapefiles can be downloaded for selected municipal areas, by USGS quad, or for the entire state. The site also offers recent high-resolution orthoimagery in MrSID format that can be used as a base map for your XMap projects.

Virtually all 50 states as well as the District of Columbia (which has one of the more extensive lists of data layers) have a GIS data repository where you can browse and download data layers. To help in your search, DeLorme is in the process of developing a data resources page that will provide a thorough list of agencies and organizations that offer spatial data. To begin with, we have pulled together a list of state-level data libraries to which we will eventually add other GIS data sources.

If you know of a data resource page that should be added to the list, please e-mail the details to prosales@delorme.com

Geographic Information System Technology for Small Wind Energy Operations

March 10, 2008

wind_farm.jpgOnce the domain of highly trained technical specialists, GIS has finally come down to earth and wind energy companies of every size and scope are realizing its benefits.
 
A simple definition of a geographic information system, or GIS, states that it is a method for studying data in its geographical context that typically includes computer hardware and software, which are used to display or process relevant data into layers. These overlaid layers of information expose patterns and relationships within the data that might otherwise go unnoticed.
 
GIS technology is ideally suited for the business of wind energy utilization and management because virtually all of the relevant data is geographically based. For every stage of the development of a wind energy project, from initial site determination to output analysis, a well-organized GIS is an indispensable tool. It can provide timely information, steer the decision-making process, and, ultimately, save money.
 
The use of a well-organized GIS can help you determine the optimal location for a wind farm project by incorporating such data layers as wind resources, terrain, property ownership, existing electric transmission lines, access roads, surface and subsurface geology, environmentally sensitive areas, avian migration routes, and much more. With all of this data concurrently influencing site selection process, it is difficult to imagine managing a project without the aid of a GIS.
 
For an organization considering the development of a GIS, a few factors must be considered before the decision is made to proceed. First and, perhaps, foremost, it is wise to compile a list of requirements that outline the functions you expect your GIS to fulfill. This list might include locating suitable project sites, gauging environmental impact, and identifying adjacent property owners. Next, you should consider what level of GIS is appropriate. Do you anticipate applying complex spatial analysis techniques or are you simply looking for a data visualization tool? Then you should ascertain how much your budget can afford. Can you justify hiring a dedicated staff member to manage your GIS or will you delegate a member of your current staff to oversee its implementation and management? You will also need to determine who will have access to the data and in what form. And so on.
 
Unfortunately, many would-be GIS adopters neglect this initial self-assessment process and jump headlong into purchasing the first GIS software that grabs their attention, only to be disappointed when their chosen solution fails to yield the expected results or is much too complicated for their needs. A wrong decision can be a frustrating, time- consuming, and expensive mistake. For GIS novices, there are numerous inexpensive alternatives to more established names in the GIS industry that usually provide an appropriate level of functionality. As well as comparing products based on a list of features and functions, it is a good idea to ask each provider about the availability of support and/or training on the use of the product, if the software will run on your existing computers, and about other wind energy companies that are using the product in question.
 
One of the most common questions posed by GIS novices is, “Where do I begin?” You have learned what a GIS can do for your business; you have studied all of the product literature; you have made your product selection; and you may even have perused the user guide for your chosen software, but that nagging question still reverberates, “What next?”
 
For convenience, the implementation of a GIS can be broken into three stages. The first stage, quite simply, is to determine the source or sources of your data. The second stage is to process your data in such a way as to expose and utilize its geographical characteristics. The third stage, often overlooked, is to develop a procedure for sharing your data or making it available to your target audience.
 
GIS Implementation Stage One – Data Sources
A fully functional GIS offers mechanisms for incorporating or converting data from a wide variety of sources and in many different formats. Some data types will already be in a format that your GIS software supports while others will require a little work on your part.
 
A solid foundation for any wind energy project is a suitable base map, preferably one that shows topography. The provider off your GIS software can often offer such a dataset. Recent aerial or satellite imagery adds further value by affording a level of accuracy for points or locations that a conventional map cannot match.
 
With the proliferation of GIS over the last decade, many agencies and organizations have created vast archives of data, much of which is readily accessible to GIS users. An online search might reveal downloadable data relevant to your project, such as wind potential, property parcels, or protected areas. Usually, incorporating this data into your GIS is as simple as following the import steps, which result in the points, lines, or polygons appearing as a layer on the map and as a collection of records in your database.
 
A more challenging process is to integrate data from a non-GIS source, such as a spreadsheet listing the names and addresses of the property owners near your planned development. Creating a GIS layer from this data and thereby assigning each object to the correct location on the map involves a process called geocoding, in which each address is matched to a street name and house number contained in the base map layer.
 
Paper maps present an additional challenge for the development of a wind energy GIS. A surprisingly large percentage of relevant spatial data is available in print form only, especially in more remote areas. Converting hard copy map prints into usable GIS layers usually involves scanning the map into a digital image format and registering the image by tagging specific points with known coordinates. This procedure creates a raster layer, which in GIS terms is a geographically referenced image. If needed, you can use point, line, or polygon tools to trace the relevant data from the imported map, creating individual records in a GIS database. This procedure creates a vector layer from which you can assign unique attributes to each object on the map. 
 
While much of the GIS data that you use to plan and manage a wind energy project is already available, the most important data layers are created as the project evolves. You can generate layers onsite from GPS observations that show specific turbine sites, planned access roads, and other infrastructure features or derive them from analysis of existing layers or aerial imagery. Geometric and attribute editing tools in the GIS software make the process of creating these and other layers as simple as drawing with your computer’s mouse.
 
GIS Implementation Stage Two – Data Processing
In GIS, displaying an object on the screen is only half of the story. Embedded in each object is a potential wealth of data which, when effectively managed, can convey much more than location.
 
As a starting point, processing your GIS data might entail simply customizing its appearance in such a way as to distinguish it from other data types. A layer that contains transmission lines might appear as dashed red lines while a layer showing property boundaries might be assigned a yellow color. With this simple step, you immediately start to see your data in a more organized way.
 
Within each layer, you can adjust the appearance of objects to reflect a particular attribute or characteristic. For example, you can shade wind resource polygons using a sequential color pattern to show areas with the lowest to highest average wind velocity. This process is referred to as classification, which involves grouping objects in a layer based on a common value or range or values. 
 
Another method for focusing on a particular element of your data is through querying. You can create queries that isolate objects within a layer based on attribute or geographic characteristics or both. For example, you can conduct a query on a property layer to determine which properties are defined as residential, and then apply a further query to create a list of those residential properties that are within a certain distance of your turbine sites.
 
GIS Implementation Stage Three – Data Sharing
Ultimately, a GIS is a communication tool. Data that has been imported and processed is, more often than not, presented in a particular fashion to a target audience. This audience might be your colleagues, customers, clients, or the community. Although this aspect of GIS development is often relegated to an afterthought, it merits attention at every stage of the process. Knowing that your data will eventually be accessed by others, you should strive to ensure that it is well structured, efficiently organized, and clearly presented.
 
In many cases, sharing GIS data necessitates little more than printing a map containing the relevant layers. Printed maps are often used for community outreach or wind farm project presentations. Another method for data exchange is interoperable file transfer within or between organizations or companies. Some GIS software titles have automated the process of facilitating the distribution of digital data by using advanced database administration tools. In other cases, simply exporting and e-mailing a file achieves the same result.
 
Finally, the Web is increasingly used as a medium for viewing GIS data layers in a fully interactive setting. Visitors to a GIS Web site can often control the view settings of the data layers and can zoom in to see more detail for a particular area. Some software developers have included the necessary Web publishing tools within their GIS programs.
 
With so much spatial data under consideration, GIS technology has become an essential tool for managing wind energy projects at every level. Indeed, there are few other industries for which GIS is more ideally suited. Fortunately, this technology has become more accessible in recent years so that any wind energy company, regardless of scale, can now apply spatial technology to every aspect of its workflow.
 
 
 
About the Author
David McKittrick has worked for DeLorme, a Maine-based mapping and GIS company, since 1997. During this time, he has served in several capacities including, most recently, as a trainer responsible for the design and delivery of GIS instruction programs to a variety of industries and businesses.


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