A version of this article was originally penned for the April 2007 edition of the DeLorme Professional Newsletter. When it was suggested that we include an updated revision for the June 2009 edition, it transpired that most of the original content still applies. So, with apologies to long-time subscribers, the following article is recycled.
The query function, which is included in both the Enterprise and Editor versions of XMap, offers both attribute and spatial querying. Queries are used to quickly identify specific records in your data and to uncover the spatial relationship between objects within different data layers. Note that queries that have been built using Enterprise or Editor are transferred with the corresponding openspace layer or through the synchronization process to users of XMap Professional. However XMap Professional cannot be used to create a query.
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A query is built by following a few simple steps:
1. After clicking the Query button on the left side of the GIS tab, select the layer to be queried from the Layer drop-down list.
2. Choose an attribute to query by clicking the cell immediately below the Attribute column heading. A drop-down list shows all of the attribute fields for that layer.
Note that the first item on the list is GEOMETRY. Select this option if you are creating a spatial query. This process will be discussed in greater detail below.
3. After selecting an attribute field, select the query Operator from the drop-down list in the adjacent cell. Depending on the data type, query operators may include “CONTAINS”, “IS EMPTY”, <, and =, among others. For instance, a query to find property owners by name within a parcel layer will be set up as follows:
Layer: Tax Parcels, Attribute: Owner, Operator: EQUALS
4. In the next cell, type or select the search criteria, which will reflect the name or value being sought. A drop-down list will offer a sample of the values that are present within the selected attribute field.
Optionally, select the User Input check box and leave the Criteria field blank, which allows unique query criteria to be entered each time the query is run. This function is particularly useful when sharing a layer with a user of XMap Professional either through an openspace file transfer or using the synchronization process as it allows them to customize the search parameters.
5. Use the Logical Operator option to build a more complex query by establishing multiple search criteria either on the same field or on different fields within the layer. For instance, by choosing the AND option, an additional line can be added that further filters the query results. The parcel query might then read like this:
Attribute: Owner, Operator: EQUALS, Criteria: Smith, Logical Operator: AND
Attribute: Value, Operator: > Criteria: 100000
In this case the query would return a list of all of the properties owned by someone named Smith that have a value of grater than $100,000. Additional lines can be added to a query as needed.
The process of building a spatial or geographic query is similar to building an attribute query. Selecting GEOMETRY from the Attribute list, as noted above, offers a unique list of query operators including, “IS CONTAINED BY”, “INTERSECTS”, and “WITHIN A DISTANCE OF”, as well as their inverses. This allows a subset of objects within a layer to be generated based on their spatial relationship to objects in another layer or based on a determined distance from a selected location or from the map center.
A powerful search option is to create a query that is a combination of both spatial and attribute query criteria. Using the parcel example again, the query could be built as follows:
Attribute: Owner, Operator: EQUALS, Criteria: Smith, Logical Operator: AND
Attribute: Value, Operator: > Criteria: 100000, Logical Operator: AND
Attribute: GEOMETRY, Operator: IS CONTAINED BY, Criteria: City School District
In this example the query results would be further limited to those that fall with the City School District polygon as delineated in a second openspace layer.
It is common for the spatial query function to be used in conjunction with XMap’s buffer tool. A buffer is polygon of a user-specified radius created around an object or group of objects within a layer. The Buffer dialog box, which is accessed by clicking the Tools button in the Workspace, offers the option to create buffer areas around all objects in a layer or just those that have been selected or queried.
As an example of the combined use of the buffer and spatial query tools, a pipeline manager can create a map and generate a list of properties that fall within a mile of his pipeline. To accomplish this he would first create his one-mile buffer polygon then build a spatial query as noted above using IS CONTAINED BY as the operator and the newly created buffer layer as the criteria.
The query function is one of the fundamental data management tools within any GIS. In XMap, the combination of buffering, attribute and spatial querying provides an efficient and effective way to filter or highlight critical objects within a layer.
A version of this article was originally penned for the April 2007 edition of the DeLorme Professional Newsletter. When it was suggested that we include an updated revision for the June 2009 edition, it transpired that most of the original content still applies. So, with apologies to long-time subscribers, the following article is recycled.
The query function, which is included in both the Enterprise and Editor versions of XMap, offers both attribute and spatial querying. Queries are used to quickly identify specific records in your data and to uncover the spatial relationship between objects within different data layers. Note that queries that have been built using Enterprise or Editor are transferred with the corresponding openspace layer or through the synchronization process to users of XMap Professional. However XMap Professional cannot be used to create a query.
A query is built by following a few simple steps:
- After clicking the Query button on the left side of the GIS tab, select the layer to be queried from the Layer drop-down list.
- Choose an attribute to query by clicking the cell immediately below the Attribute column heading. A drop-down list shows all of the attribute fields for that layer.
Note that the first item on the list is GEOMETRY. Select this option if you are creating a spatial query. This process will be discussed in greater detail below. - After selecting an attribute field, select the query Operator from the drop-down list in the adjacent cell. Depending on the data type, query operators may include “CONTAINS”, “IS EMPTY”, <, and =, among others. For instance, a query to find property owners by name within a parcel layer will be set up as follows:
Layer: Tax Parcels, Attribute: Owner, Operator: EQUALS
- In the next cell, type or select the search criteria, which will reflect the name or value being sought. A drop-down list will offer a sample of the values that are present within the selected attribute field.
Optionally, select the User Input check box and leave the Criteria field blank, which allows unique query criteria to be entered each time the query is run. This function is particularly useful when sharing a layer with a user of XMap Professional either through an openspace file transfer or using the synchronization process as it allows them to customize the search parameters. - Use the Logical Operator option to build a more complex query by establishing multiple search criteria either on the same field or on different fields within the layer. For instance, by choosing the AND option, an additional line can be added that further filters the query results. The parcel query might then read like this:
Attribute: Owner, Operator: EQUALS, Criteria: Smith, Logical Operator: AND
Attribute: Value, Operator: > Criteria: 100000In this case the query would return a list of all of the properties owned by someone named Smith that have a value of greater than $100,000. Additional lines can be added to a query as needed.
The process of building a spatial or geographic query is similar to building an attribute query. Selecting GEOMETRY from the Attribute list, as noted above, offers a unique list of query operators including, “IS CONTAINED BY”, “INTERSECTS”, and “WITHIN A DISTANCE OF”, as well as their inverses. This allows a subset of objects within a layer to be generated based on their spatial relationship to objects in another layer or based on a determined distance from a selected location or from the map center.A powerful search option is to create a query that is a combination of both spatial and attribute query criteria. Using the parcel example again, the query could be built as follows:
Attribute: Owner, Operator: EQUALS, Criteria: Smith, Logical Operator: AND
Attribute: Value, Operator: > Criteria: 100000, Logical Operator: AND
Attribute: GEOMETRY, Operator: IS CONTAINED BY, Criteria: City School District
In this example the query results would be further limited to those that fall with the City School District polygon as delineated in a second openspace layer.
It is common for the spatial query function to be used in conjunction with XMap’s buffer tool. A buffer is polygon of a user-specified radius created around an object or group of objects within a layer. The Buffer dialog box, which is accessed by clicking the Tools button in the Workspace, offers the option to create buffer areas around all objects in a layer or just those that have been selected or queried.
As an example of the combined use of the buffer and spatial query tools, a pipeline manager can create a map and generate a list of properties that fall within a mile of his pipeline. To accomplish this he would first create his one-mile buffer polygon then build a spatial query as noted above using IS CONTAINED BY as the operator and the newly created buffer layer as the criteria.
The query function is one of the fundamental data management tools within any GIS. In XMap, the combination of buffering, attribute and spatial querying provides an efficient and effective way to filter or highlight critical objects within a layer.
One of the recurring themes that you will often read in DeLorme’s XMap informational literature is that XMap is equally well suited as a standalone GIS application or as an extension to your existing GIS infrastructure. As XMap continues to evolve, more and more emphasis is being placed on improving the interoperability with third-party GIS software and databases and on simplifying the exchange of data between the different platforms. Seen in this light, XMap functions as a bridge between your current GIS setup and those who need access to the data on an ongoing basis, namely your field staff or mobile workforce.
Perhaps the most appealing function of the XMap suite for GIS administrators is the redlining tool that is included in XMap Professional. As a component of the synchronization process, this easy-use-annotation feature allows field workers to communicate with their GIS administrator using a variety of markup tools. These redline layers are automatically delivered to the central database with each synchronization, allowing the data administrator to correct or update the master layers as necessary.
Our first reseller in the spotlight is Tulsa, Oklahoma-based 
On August 27th, 2008, just before midnight, I received a call from Don, an operations leader from the Skagit Mountain Rescue team. They needed some help from Bellingham Mountain Rescue for two climbers reportedly stuck on a ledge somewhere near Spire Point. The climbers were near the end of completing the “Ptarmigan Traverse,” a five-day thru hike in the North Cascades and were stuck on a ledge in bad weather with 100 ft visibility, not knowing exactly where they were. I called and woke up one of our SAR deputies from the Whatcom County Sheriff’s Office (a pleasure to wake them up instead of what is typically the reverse) to let them know we’d been requested. I then got to work putting a team together and downloading maps to my PN-20. Spire Point is located quite a way into the North Cascades, and with the normal road/trail system being washed out, I knew there was going to be quite a bit of bushwhacking and/or route-finding. It also meant our chances of getting back in there and finding them quickly without helicopter support was slim.
The flight in was interesting. We followed roads and valleys into the area, keeping a close eye on the weather ceiling. And one by one our hopeful insertion points were shut out by the bad weather. All the while, though, I sat next to the side door of the helicopter with my PN-20, keeping track of where we were relative to our insertion points. As we exhausted our last option, though, I asked the pilot to head back west and try another option. I had seen a small lake on the topo map of my PN-20 that just might be accessible via a small side valley. We rounded the corner into the valley and I asked the pilot if he’d be comfortable poking his nose just over the trees at the head of the valley. We were just below the ceiling but he agreed since it was basically our only hope. As we skimmed over the trees, Itswoot Lake appeared with a perfect little landing zone on the south end of the lake (N48° 17.870′, W121° 5.319′).
This latest release of the XMap USA Topographic Data includes a significant number of updates and other improvements including:
A project is a file that stores certain settings with XMap and records a specific map view that can be reloaded at later date. Projects, which are assigned a .xmp suffix, are saved in the Projects folder in your DeLorme Docs folder which, for XMap 6 users, is in “My Documents” on your local computer, and for XMap 5 and previous users, is at the root of your local hard drive (typically C:\DeLorme Docs).
On occasion, DeLorme customer service representatives are called on to clarify that the images and sample maps on the xmap.com pages do not always reflect what new XMap users are likely to see immediately after they install the software. These images are intended to represent simulations of how the functionality of XMap can be applied within certain industries and for particular applications. The process of composing these maps typically involves utilizing data from a variety of sources, and often it entails creating custom symbology that is more applicable for representing the features on a particular map. It should also be noted that all of the sample maps have been created using the tools that are readily available to all XMap users.
After Hurricane Ike recovery the Earthmate PN-20s were deployed to collect location data on the status of oil and gas facilities as well as damaged or sunken vessels along the coast. In preparation for the storm, virtually all oil and gas operations in the impacted area of the gulf had been shut down and secured, however an immediate assessment on the level of damage was critical to mitigate further harm to the natural environment. This data collection effort allowed GIS specialists at the GLO to create maps depicting each location and provided the means for response agencies to efficiently allocate the necessary resources where the need was greatest.
DeLorme’s innovative Map Library subscription service, which is available through the Netlink tab in XMap 6, offers unlimited access to all of these map datasets and more for a full year. Simply select the grid tiles that cover your area of interest, choose the type of data, and submit your order. Your custom dataset is usually available for download within minutes and is automatically displayed in XMap.
Longtime users of XMap will know that ImageReg is not a new feature of the software. This useful and often overlooked tab has been included with XMap for many years and it continues to serve an invaluable role in the XMap suite. ImageReg is used to register or align digital images or scanned maps or photographs to an underlying base map. This process allows you to create a raster map layer from any image by applying geographic coordinates to the image file.
The Reduce button reduces the color depth of the image from 24- to 8-bit.