Tag Archives: Data Modeling
Using the Global Self-consistent, Hierarchical, High-resolution Shoreline (GSHHS) database
By Mark Smithgall, Cartographic Product Engineer
Where can you find the largest island in the largest lake on the largest island in the largest lake on the largest island in the largest lake in the world? I stumbled across a rather unique Wikipedia factoid the other day: “When Moose Flats is temporarily submerged, Moose Boulder becomes the largest island in the largest lake [Moose Flats] on the largest island [Ryan Island] in the largest lake [Siskiwit Lake] on the largest island [Isle Royale] in the largest lake [Lake Superior] in the world.” This geographical tongue-twister led me to explore the Global Self-consistent, Hierarchical, High-resolution Shoreline Database (GSHHS) to see if this fact was true. I couldn’t actually confirm it using these data because they only contain enough detail to see ponds on islands in lakes on continents, but in the process I did find out what a great resource these data are, so I wanted to share that with you in this blog entry.
Xray for ArcGIS 10 Updated
ESRI, in conjunction with Vertex3, has released revised versions of Xray for ArcGIS 10. The Xray Add-In for ArcCatalog can be used to develop, refine and document your geodatabase designs. The Xray Add-In for ArcMap can be used to document the properties of your map documents (MXDs).
This release includes the following enhancements:
- Added support for Dataset, Field, and Domain Descriptions. These tools will create spreadsheets where you can document all descriptions in one place.
- Added support for SDE and Workgroup Geodatabases. You can now select .gds and .sde connection files in ArcCatalog to export/import XML Workspaces.
- Default SVG settings/options can now be changed in an XML Document.
- FGDC Metadata support (ESRI patch for ArcGIS Desktop).
This release also addressed the following bugs:
- File locking error messages that were caused by a file reader object not being closed correctly in the application.
- The SVG settings menu was not updating correctly when the “Visio” option was selected or checked.
- Improved automatic layout of SVG graphics in Visio.
We hope you’ll find these tools valuable when developing and sharing your ArcGIS 10 geodatabases and map documents and look forward to your feedback.
Xray for ArcGIS 10 Beta Available for Download
ESRI, in conjunction with Vertex3, has released Xray for ArcGIS 10 Beta. This update of the Xray tools you’ve found previously on ArcScripts, provides two ArcGIS 10 Add-Ins you can use natively in ArcCatalog or ArcMap.
The Xray Add-In for ArcCatalog can be used to develop, refine and document your geodatabase designs. The Xray Add-In for ArcMap can be used to document the properties of your map documents (MXDs).
This release of Xray for ArcGIS 10 requires ArcGIS Desktop 10 and works with Personal and File Geodatabases. Future releases will support Workgroup and Enterprise Geodatabases. Xml workspace documents from earlier releases of ArcGIS can be opened, but users should upgrade their geodatabase to ArcGIS 10 before using Xray. Installation help and additional release notes can be found in the attached.
We hope you’ll find these tools valuable when developing and sharing your ArcGIS 10 geodatabases and map documents and look forward to your feedback.
Using the Buffer tool in ArcToolbox (and comparing with the Buffer Wizard in ArcMap)
By Margaret Maher, Esri Support Services Specialist
In this blog entry, I discuss using the Buffer Tool in ArcToolbox. I also compare the ArcToolbox Buffer Tool with the Buffer Wizard in ArcMap. The Buffer Tool, located in ArcToolbox > Analysis Tools > Proximity toolbox uses different methods to calculate buffers. The method used by the tool depends on the type of feature being buffered.
An important thing to understand is that when creating buffers for line and polygon features, the Buffer Tool in ArcToolbox uses the coordinate system of the data being buffered by default. When points are being buffered, another method is used which will be described later in this article. Continue reading
Historical GIS template: Boston 1775
By Charlie Frye, Esri Chief Cartographer
This post, is to announce the release of a map template for historical GIS called Historical GIS: Boston 1775. If you’ve never given historical GIS a second, or a first thought, you might find the contents interesting and maybe even applicable to your work. Consider that the vast majority of GIS data is historical, even if it’s only a few minutes old.
Genealogy and history have been hobbies of mine for years now, and I’ve since developed an interest in colonial U.S. history– in particular, the U.S. Revolutionary War. For me, GIS and mapping provided an obvious way to make sense of the history I found fascinating. As such, I found it more than a little ironic that relatively few of the historically-inclined geographers I’ve met had turned to GIS much less demonstrated GIS-based methods as a sound basis for scholarly historical inquiry. But, I’ve been happy enough to take that opportunity to blaze a trail. Continue reading
Quick & dirty method & tips for creating building footprint features
By Charlie Frye, Esri Chief Cartographer
From time to time we’ve had to create some building footprint data. A colleague was in my office yesterday looking at the map to the right, and remarked that he thought that adding building footprints to maps “humanizes” the map. An interesting observation, and one that I’m not inclined to argue against.
We’ve learned a few tricks for making haste with little or Continue reading
Symbolising data with lost data links
By Charlie Frye, Esri Chief Cartographer
I frequently come across data which has lost data links (a red!). This occurs when the data has been moved or no longer exists, thus breaking the link. On some occasions, even after I tracked down the data and repaired the data source, the symbology still didn’t draw — it exists, but the wrong field is listed on the Layer Properties Symbology tab. Usually the draw category (Value field) has defaulted to a non-matching field. Simply changing the Value field does not do the trick. Continue reading
Expressing slope
By Aileen Buckley, Mapping Center Lead
The vertical change in the elevation of the land surface, when determined over a given horizontal distance-along a road or stream, for instance-is known as its slope (figure 1). There are three primary ways to quantitatively express the slope between two points. In each, the lower the slope value, the flatter the terrain, and the higher the slope value, the steeper the terrain. The slope values may be expressed as a ratio, as a percentage or as an angle. Continue reading
I remember making this feature class…I wonder why?
By Charlie Frye, Esri Chief Cartographer
Have you ever wondered where a feature class came from as you’ve browsed over one of your geodatabases in ArcCatalog? I think most of us have, and probably more often than we’d like to admit. In the example shown here to the left, I made these datasets a few weeks ago, and I have no idea what “GN” means, and if or how I selected, simplified, or dissolved the data. Continue reading
