GIS Tech News (#68)

20 Oct, 2008

Tax Mapping into the Futurep>

To locate county-line monuments from a bygone era, technicians in New York's Orange County Tax Map Department rely on an array of modern GIS software and GPS hardware.

By Mike Kolka

It's said that nothing's certain but death and taxes — but in order to tax with certainty, government agencies must maintain accurate records of the properties in their domain. Confirming the size and location of parcels is a challenge that requires technological aid. In the past, surveyors were limited to devices such as long chains of wire links, but today they can choose from a bevy of sophisticated implements. These modern tools made it possible for New York's Orange County Tax Map Department to locate county lines — and find long-lost boundary markers that are more than 200 years old.

It all started in May 2007, while I was using ArcEditor to update a GIS parcel layer. I was placing our tax maps (DWG and raster) under our SHP file for the Town of Highlands, when I noticed that the two didn't match. Using our Tax Map Record System (TMRS) for parcel information, I pulled the deeds for all lots and subdivision maps. I soon realized that we have deeds and maps transferring ownership that date back to the late 1700s.

Using AutoCAD 2008 Land Development Desktop (LDD), I plotted each lot, edge-matched them, and placed our ortho images underneath to help me get an idea of where the maps should be in "the real world." Then I was able to start identifying problems — including the fact that there were federal lands surrounding my parcels. That's when the fun started.

I contacted our map room personnel, who provided me with West Point survey maps from the War Department that were dated 1939. I also contacted West Point's GIS division. After several e-mails and phone calls they were able to send me the Point SHP file, with Listening Hill serving as the main tie point. Using this information, I was able to place the maps in their correct geographic location. But as I was tying the maps together, another problem arose in the form of more federal lands: the Palisades Interstate Park (PIP). Read more »

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Editor's note: This feature also appeared in Geospatial Weekly Newsletter (October 17, 2008).


CAD Clinic: Civil 3D Tutorial
Description Key Sets and Point Styles, Part 4

By Phillip Zimmerman

In the last article, I covered the settings for a point label. These settings control visibility, readability, size, location, and dragged state behavior. This article reviews the creation of a point label named Component.

Label Style Composer
The Label Style Composer dialog box contains all the settings from last month's article. This dialog box defines the basic ground rules for a label. The Layout tab defines the content of the label. A label may have one or more named components (see left side of figure below). Each named component can contain one or more object properties (see right side of figure below).

Each named component anchors to the feature or another named component. In the left side of the figure above, the Point Description anchors not to the coordinates, but the named component Point Elev. In the figure's right side the Northing/Easting name component anchors to the point's coordinates (the feature). Read more »

Mark Your Calendar: GIS Events

Geospatial Applications and Solutions: A Working Model
November 12, 2008
Adelaide, Australia
IMAGINiT Australia will host a geospatial industry briefing for those working in the mining, defense, utilities, service, banking, education, or government sectors who need to improve their organization's efficiency and productivity. Topics will include geospatial technologies, national solutions, and integration. Read more »

Cadalyst's complete list of upcoming events is always available on our Web site. Our sister Web site,, also offers a full calendar of GIS-related events.