Data Presentation: Value-Added GeoPDFs

When I initially heard about GeoPDF I thought it sounded like a good enabling technology for people without advanced geospatial expertise or access to the appropriate software. After all, anyone can view a PDF. Typically I thought of it in the context of viewing RGB orthophotos... Fast-forward to the present: lately I've been thinking about ways of presenting fused data, and this is where GeoPDFs came to mind. In particular I wanted to present terrain and image data.

For input data I started with some edge-matched orthophotos of Sligo, Ireland and processed XYZ LIDAR data of the same area (data courtesy of OSi). I processed the data in LPS and IMAGINE, which basically involved importing the LIDAR data and converting it to the IMAGINE IMG format, and then creating a shaded relief map out of it. For the imagery I mosaiced several tiled input images into a single orthomosaic. The processing resulted in three products: an RGB image file, a shaded relief image, and a DEM. To put them all together I used the "Layer Stack" function in IMAGINE, which resulted in a 7-layer 8bit IMG file.


Next, I converted the IMG to a GeoPDF. This was a painless process and produced a 7-layer PDF file. My input file covers a fairly broad area and was a few gigs (2.7GB to be precise) in size so I used a JPEG compression quality factor of 60, which for visual analysis creates a fairly sharp-looking image in a PDF format with a much-reduced size of 122MB. This allowed me to open up the image in Adobe Reader and view the image.

Because the first three layers of my image are the RGB orthomosaic, this is what is displayed when opening the PDF in Adobe Reader. I also have the GeoPDF Toolbar (recently renamed to TerraGo Desktop) loaded as well for various measurement and manipulation functions:

(click any of the screen captures for larger views)

By clicking on the "Layers" button I could adjust the band combinations for RGB to display the shaded relief.


It was also possible to display various fused results. In this example I am displaying Red and Green from the orthomosaic and then loading the DEM into the Blue channel. This means the colors are skewed but the benefit is that you can see the image feature details and also get a notion of the high-relief areas. In this case high relief shows up as dark blue, and the absence of blue indicates low-relief (e.g. the upper left areas).


Note that many kinds of band combinations/visualizations are possible with this fused product.

Many thanks to Adam Estrada for assisting with the GeoPDF part of this workflow. I also plan on making the dataset available soon (I'll hopefully get it uploaded tonight).

LPS 9.3.1 Now Available!

We've just released our first Service Pack for LPS 9.3, called LPS 9.3.1. It is available from our support site and is located in the "Fixes and Enhancements" section. In addition to numerous bug fixes, LPS 9.3.1 (which is a shared Service Pack with ERDAS IMAGINE) also contains the following features and improvements:

LPS Core

• Added required entry of Average Terrain Elevation when creating a block file for Orbital Pushbroom sensors. This entry overrides the generally less accurate method of using the sensor metadata to derive a mean elevation.

Stereo Point Measurement/Classic Point Measurement

• Improved and simplified image loading.
• Added “Create Ground Control Point” feature that calculates 3D ground coordinates from image points which are measured in at least two images. This is particularly useful in transferring control points from more accurately oriented imagery into lower accuracy imagery.
• Improved several icons to maintain consistency with other dialogs in LPS and IMAGINE.
• Improved image tracking to use the mouse wheel to adjust the image positions in relation to each other and remove the x-parallax.

RPC Generation

• Added fields to give the user the ability to control parameters of the RPC fit cube. This can help improve the fit accuracy.
• Added an option to output a report file that shows where higher residuals are falling, check point and fit point statistics, and other information that help to refine the results on subsequent generations.

LPS Core Triangulation

• Improved RPC refinement by automatically detecting points with parallel rays and using these parallel rays as an additional constraint. This eliminates the need to manually delete points with no convergence.

ERDAS MosaicPro

• Improved memory management during Image Dodging and seamline generation.
• Faster seamline refreshing after editing and undo.
• Improved performance when running MosaicPro with a shapefile or an AOI with multiple polygons as a single output mosaic.

Defense Productivity Module

Image Slicer

• Added capability to input active area.
• Named all segment IDs from West to East regardless of how images were captured.
• Improved quality of segment boundary computation.
• Added an option to trim the nonoverlapping portions of the stereo segment image pairs.
• Changed the pyramid generation so it is driven by the IMAGINE preferences rather than always making pyramids after segmentation.

TFRD AMSD Calibrator

• Eliminated requirement that LPS be installed to generate an Image Slicer project file (.isproj).
• Added an option to output the rectangle and stereopair accuracy values from AMSD to a text file.

IMAGINE Radar Mapping Suite

• You can now use the Subset Processing Step to extract portions of the input images in InSAR from which to generate a DEM.
• Multilook factors are now displayed directly on the Reference DEM Processing Step of InSAR.
• Coherence window values are now edited within the Interfere Processing Step of InSAR, and a working Coherence image is generated and available for viewing.
• The Register step in InSAR has been renamed Coregister in which the match image is coregistered to the reference image.
• In the Coregister step, there are now two tabs named Coregistration Input Parameters and Coregistration Output Coefficients. The Coregistration Output Coefficients tab contains a CellArray reporting polynomial coefficients which describe the pixel shift of the match image along the x-direction and along the y-direction.
• In the Height step of InSAR, you can now select an interpolation method for the resample process as part of the chosen rectification method.

ERDAS IMAGINE – General

• Chooser icons, such as those for selecting colors or Annotation styles, now have two portions. Click the top portion to open the Chooser dialog directly; or click the bottom portion to open the selection menu as before.

IMAGINE GLT

• GeoPoint Annotation has a new Properties dialog where you can select a template for the text to be displayed. You can also configure options indicating where the label is to be placed and whether or not there is a leader line from the label to the point. The text template can be a dynamic coordinate (as before), an incrementing number, a static string or a combination of coordinate or incrementing number and static string.

IMAGINE Viewer

• In addition to the Annotation Alignment tool, the Annotation menu and tool palette now contain separate options for aligning annotation vertically or horizontally.
• You can now save a Footprint layer in the Viewer/GLT as Annotation or as a shapefile.

IMAGINE Composer

• Leading zeros are now displayed for coordinates in Grid/Ticks.
• You are now able to specify the text to be displayed for the units in an Annotation Scale Bar.
• When generating an Annotation Grid/Tick, you can now specify a rotation angle for the coordinate labels.

Anaglyph Generation in ERDAS IMAGINE

Last week Adam Estrada over at the GeoPDF blog wrote a great post regarding anaglyph GeoPDFs. He also posted a link on how to create anaglyphs manually and mentioned that they could also be created in ERDAS IMAGINE. I will walk through the steps on how to perform this operation in IMAGINE.

First of all, you need to open up Image Interpreter, choose Topographic Analysis, and then select "Anaglyph". Here is what the Topographic Analysis toolset looks like.
After selecting the "Anaglyph" tool, it is necessary to specify a few parameters. Since the anaglyph effect is created by producing an offset based on relief, a terrain file needs to be specified. There are various options, including the ability to exaggerate the relief. Next the input image needs to be defined, along with the output image and format. One flexible aspect of the tool is the ability to define the color for the left and right "lens" of the anaglyph glasses. Most anaglyph glasses are red and cyan, so the default option is a Red / Green and Blue (Cyan) combination for the left eye and right eye. It is also possible to define the output bands along with defining a subset definition (e.g. if you only want to produce a small anaglyph area from a large image mosiac).

Here's what the dialogue looks like with the settings I used:

And here is what the final anaglyph image looked like:

Note that you may need to click the link to truly see the effect. Also note that the effect that be modified with the "exaggerate" option - this can be used to increase the effect (which may be necessary depending on the scale of imagery being processed). While it is certainly possible to "manually" create anaglyphs in a number of packages, the Anaglyph tool in IMAGINE adds a degree of automation that isn't available in other solutions. For example, if you want to serve up anaglyphs for an entire city on a web application, you can use the IMAGINE batch tool to process several hundred (or thousands) of images - which beats processing them one-by-one.

Upcoming ERDAS Webinar: Mosaicking

I'll be doing a webinar next week on mosaicking, which was just announced on the ERDAS web-site yesterday. The main focus will be planning considerations for frame photograph mosaicking, processing techniques (radiometry, image manipulation, seams, output considerations), and final mosaic product generation. This may be of interest to both LPS and ERDAS IMAGINE users (along with anyone generally interested in mosaicking), since I'll be using MosaicPro for the processing: an add-on module to both LPS and IMAGINE.

The registration page is here. We'll be hosting the webinar at both 3AM and 11AM EST, so please feel free to join us for either session!

Leica Geosystems Chinese Earthquake Press Release

This press release was sent out nearly a week ago. I wanted to highlight it since I haven't seen much about it anywhere else and I think it is a great example of how rapid response applications can save lives (and hey, there's photogrammetry involved too). I won't rehash the story here since you can read about it in the press release, but I would like to highlight a few key points.

We hear a lot about how aerial photography is used for rapid response mapping, but an important consideration to the type of airborne sensor employed for such applications. On reflection, the ADS40 is a great camera for this sort of thing. Why? The fact that it is a pushbroom sensor offers a great advantage. This means it collects a "pixel carpet" instead of the typical 4Kx4K or 9Kx9K frame camera. This is critical for rapid mapping applications because the image analyst (for example, the person who saw the SOS in the press release image) doesn't have to waste time loading frames or performing a large mosaicking job with a lot of seams. They can either review the strip directly or run a quick and dirty mosaicking job that doesn't require much in terms of seam edits.

Make sure you check out the image associated with the press release (link below). It is fairly high-res when you zoom in and the earthquake damage is noticeable. You can also see from the bottom of the image that the screen capture was taken from ERDAS IMAGINE.


At any rate, I will write a Sensor Spotlight on the ADS40 in the future and highlight some of the other applications it is suited for..

LIDAR and Imagery Collection for Rapid Response Mapping

At our ASPRS UGM last Tuesday I presented a case study on rapid response mapping. The case study was an interesting application, so I thought I would share it here as well. The focus was on a joint ERDAS (software) and Leica Geosystems (hardware) exercise conducted last summer called "Empire Challenge 2007". This was joint military exercise for testing intelligence, surveillance and reconnaissance (ISR) concepts. The exercise was initially developed after technical issues were identified in sharing ISR information between allies in hotspots such as Afghanistan. I wasn't personally at the event, held near China Lake (California), but did get a chance to work with some of the data that was collected.

For the ERDAS/Leica team, the exercise involved flying a Cessna 210 mounted with both LIDAR and optical sensors over a project area and then creating final data products immediately after downloading the data. The team spent approximately three weeks on-site, and during this time they worked in three project areas and were able to fly, collect, and process a few thousand images and a massive quantity of LIDAR data.

The hardware consisted of an ALS50 (LIDAR), the soon-to-be-released RCD105 digital sensor, as well as Airborne GPS/IMU, a GPS Base Station, and some data processing workstations. While not officially released by Leica, the RCD105 was first "announced" at last years Photogrammetry Week in Stuttgart, Germany. More specifically it was discussed in this paper by Doug Flint and Juergen Dold. It is a 39 megapixel medium-format digital camera - which makes for a great solution when coupled with the ALS50 airborne LIDAR system. Here is an image of the RCD105:The software mix covered several areas. These included:

• Flight planning and collection software (FPES and FCMS)
• LIDAR processing (TerraScan)
• GPS and IMU processing (IPAS Pro, IPAS, CO, and GrafNav)
• Image processing (ERDAS IMAGINE)
• Photogrammetric Processing (LPS, ERDAS MosaicPro, ERDAS ImageEqualizer)
• Quality Control (ERDAS IMAGINE)
  

There were three main missions that were flown. These included:

• A basemap collection flight. At 3048 meters, this was the highest altitude flight. The imagery GSD (Ground Sample Distance) was 0.3 meters. Data products included an orthomosaic, georeferenced NITF (National Imagery Transmission Format) stereo pairs, NITF orthos, a LIDAR point cloud, and a LIDAR DEM.
• A tactical mapping mission. This was a lower altitude flight (914 meters) collecting imagery at a GSD of 0.06. This was "tactical" as it covered specific project areas - as opposed to the broad swath of data collected from the higher altitude basemapping flight. Data products included an orthomosaic, geoferenced NITF steree pairs, NITF orthos, and a LIDAR point cloud and DEM.
• An IED corridor mission: basically covering a linear feature (a road). This was the lowest altitude and highest resolution flight (at 305 meters and 0.04 GSD), which produced NITF stereo pairs, NITF orthos, as well as a LIDAR point cloud and DEM.

The project area was pretty typical inland Southern California scrub/desert. Here's a photo from the ground:

And here's one of the images (in this case shown during point measurement - a part of the triangulation process - in LPS):

As you can see, the radiometry is tough! This is why ImageEqualizer had to be used to perform radiometric corrections.

Most of the workflow was relatively standard (mission planning, data collection, and the photogrammetric processing), but some of the final product preparation steps were pretty interesting. Since one of the main goals of the entire exercise was to produce intelligence products that could be shared with other groups, special consideration had to be given to exactly how the data would be formatted for delivery to the other Empire Challenge groups ingesting the data. Since the groups accepting the data could have been using any number of software packages, the ERDAS/Leica team had to steer clear of proprietary formats. However, one thing that many image processing and photogrammetry products usually have in common is the ability to ingest images with an associated RPC (Rational Polynomial Coefficient) model. Here is a good description of RPCs in GeoTIFF. Since this was a military exercise, the images (processed as tiffs) had RPCs generated in IMAGINE and then were exported to NITF. This made is possible to pass along the final data products to several groups without any data format/interoperability issues. One thing to note is that "RPC Generation" was introduced in the IMAGINE 9.1 release in early 2007.

By the end of the project the total processing times for the various missions could be measured in hours. The basemap mission took the longest (about three days for the entire end-to-end process), but it had approximately 900 images along with the LIDAR data.

Here's a screenshot of an orthomosaic over terrain. The radiometry hasn't been fully processed in this image, but it gives you an idea of what the project area was like:

Triangulated Irregular Network (TIN) Formats and Terrain Processing

One issue in the mapping community is that there is no standard format for Triangulated Irregular Network (TIN) terrain files. Most geospatial applications use proprietary formats, which presents serious interchange problems when moving the data around (e.g. from clients to customers, or even within an organization). Unfortunately we are guilty of this as well in LPS, with our LTF TIN format. Many people get around the limitations of proprietary formats by using ASCII as a common interchange format, where the TIN mass points are listed in XYZ for each row (separated by commas, tabs, or whitespace). Some systems also support the notion of points codes for breaklines, which are a critical part of the TIN structure. The main problem with ASCII is that once you get over several million points, the file can be cumbersome to deal with - which means it may be necessary to divide up the data into tiles. Alternatively you can convert the TIN to a raster format, but this can be undesirable if you have dense mass or unevenly distributed points, or if you have breaklines in the TIN (since rasters don't support breaklines).

A case in point is the LIDAR data from the Washington State Geospatial Data Archive. While there are standards for LIDAR data, most commercial applications do not (yet) natively support it. Hence there is a need to make the data available in alternate formats. The data is available in ASCII and TIN format for each quarter quad, but the TIN format is in .e00 format, which is an old interchange format developed by ESRI. Hence, the site recommends Importing the .e00 files into ArcMap in order to use them. The only issue with that is that you need ArcMap... This is likely a reason for including XYZ ASCII as an option as well. Another option is a 3 meter DEM for the entire coverage area, which is possible to download from here. It is in Arc/Info binary grid format though...

So how do we handle all of this in LPS?

There are a few different options here, and the LPS and IMAGINE groups have been working on a solution. Prior to the LPS/IMAGINE 9.2 release, users had to either use the 3D Surface Tool in IMAGINE or the terrain Split and Merge tool in LPS Core. In 9.2, and moving forward in future releases, we are consolidating our efforts by extending the LPS Split and Merge tool and making it available in IMAGINE, which we have renamed to the "Terrain Prep Tool". It is available in Data Prep > Create Surface in IMAGINE, or from Tools > Terrain Prep Tool in the LPS Project Manager.
The Terrain Prep Tool adds new split/merge functionality inherited from LPS as well as resolving some longstanding limitations associated with the 3D Surface Tool (e.g. it dramatically increases the number of points that can be handled). For 9.2 we also added a few formats such as LAS and two flavors of ASCII (with and without point codes for breaklines). The 3D Surface Tool will likely remain available for a few more versions, until we have fully replaced it's functionality in the Terrain Prep Tool.

Service Pack 1 for LPS and ERDAS IMAGINE 9.2 Now Available!

The new service pack for LPS and IMAGINE is now available for download on the ERDAS Support Site. Instead of releasing separate service packs for LPS and ERDAS IMAGINE, we decided to release a single consolidated SP that covers both products, which should make life easier for users.

While the SP mainly consists of fixes, we have some new features in LPS that I wanted to highlight as well. One of the main new features is the Post Editor in the Terrain Editor. This tool (see the screenshot below) is for gridded terrain data, and allows you to quickly jump from post to post, adjusting the Z value as you go. The navigation is also device-mappable, so you can use keyboard shortcuts or buttons on an input device (e.g. a Topomouse).Also of note is that we have extended the "Adaptive ATE" option to work with all supported sensor models, as it previously just worked for frame and ADS40 data. We were able to see some good improvements for several satellite sensors we tested with.

Here is a complete list of the fixes and enhancements:

LPS

· Automatic Terrain Extraction (ATE):

o Added note to online help for Adaptive ATE explaining that image datasets vary and you must check your results and make selections (both the method and the ATE parameters) based on your particular datasets. [LPS-1626]

o Adaptive ATE correctly generates DTMs using ADS40 images and does not show the error message "failed to transform points". [LPS-1531]

o Resolved a "Bad allocation" memory error when using ADS40 images to generate a DTM in .img format. [LPS-1540]

o Added note to OLH advising user about using pyramid levels and effective building filtering. [LPS-1582]

o Adaptive ATE now measures points over the complete stereo model area; not just 70 to 80% (center part). [LPS-1482]

o Fixed DTM extraction "out of space" error so that the user can cancel the process. [LPS-1548]

o Fixed an ATE issue associated with the "individual files" output setting. [LPS-1313]

o Added support for all sensors in Adaptive ATE (not just frame cameras and ADS sensors). [LPS-1562]

· Block Triangulation:

o Synchronized units of measure for GCPs and residuals in Refinement Report. [LPS-1267]

· Documentation:

o Added tip to Mosaic OLH explaining how to correctly lay out ADS L2 images. [LPS-231]

o Enhanced content for "Set Constant Z" in Terrain Editor OLH. [LPS-1341]

o Updated OLH hyperlink in Camera File Info. [LPS-1508]

o Improved the content of the View Manager OLH. [LPS-1465]

· Terrain Prep:

o Eliminated write permission errors when opening LTF files. [LPS-1187]

· Frame Editor:

o Eliminated LPS blockfile issues when editing the model parameters in Frame Editor for the WorldView Orbital Pushbroom and SPOT5 models. [LPS-1545]

o "Cancel" option cancels current image in the Frame Editor and not the selected image in the LPS project manager cellarray. [LPS-1577]

· Interior Orientation:

o Changing the camera selection for a block file (after performing IO with the wrong camera) no longer prevents subsequent IO with the same block file and the new camera selection. [LPS-1283]

· LPS General:

o Synchronized units of measure for the Average Flying Height (Frame Camera) and Average Elevation (Orbital Pushbroom) in Block Property Setup with the units in the block file. [LPS-1575]

o New Feature: Stereo Analyst - "Extend Features to Ground", which uses a 3D Polygon Shapefile and extends the segments of each polygon (as faces) to the ground to form solid features (e.g. Buildings). [LPS-1567]

o The Average Elevation, Minimum Elevation and Maximum Elevation units in RPC Model projects are now displayed in the project vertical units in the Frame Editor [LPS-1597]

o Eliminated write permission errors when opening LTF files. (See LPS-1187) [LPS-1492]

o Added QuickBird/WorldView NCDRD format support to online help. [LPS-1610]

o Added support for the Latvian Gravimetric Geoid (LGG98) and Latvian Coordinate System (LKS-92) [LPS-1557]

o Added support for the LHN95 geoid (Switzerland). [LPS-1556]

· MosaicPro:

o Fixed MosaicPro occasional issues when running Image Dodging with default settings on tiled TIFF images. [LPS-1554]

o Improved performance for seam polygon generation with "most nadir", "geometry", and "weighted" options. [LPS-1552]

o Fixed occasional display issue when one or more images have been mosaicked but do not display. [LPS-1578]

o Fixed MosaicPro occasional issues when working with pyramid layers (Image Dodging and Mosaicking). [LPS-1553]

o Resolved an issue associated with clipping Shapefiles that do not contain projection information. [LPS-585]

· Orthoresampling Process:

o Resolved an issue associated with orthophoto generation when using ATE-derived LTF files in LSR coordinate systems. [LPS-1579]

· Import/Export:

o Enhanced Importer for ISAT projects with multiple flight lines. [LPS-1550]

· Sensor Models:

o In special cases where the RPC does not have a change in the Z value, Triangulation failed with an error of "error with computing default ground delta". These special cases now triangulate correctly. [LPS-1510]

o Added support for NITF NCDRD format in orbital pushbroom QuickBird/WorldView model. [LPS-1551]

· Terrain Editor:

o New Feature: Post Editor (Terrain Editor) - allows a user to quickly move through points and adjust the Z value for selected points in grid terrain files. [LPS-484]

o Enhanced jpeg image display quality in Terrain Editor. [LPS-1547]

Leica Stereo Analyst

· Stereo Analyst:

o Extend Features to Ground will convert flat 3D polygons into solid shapes by extruding each polygon to the ground. Ground elevation may be defined by Shape Attributes, Terrain Dataset or a constant height. Output may be directed to a Multipatch Shape File or 3DS file. [SAI-136]

ERDAS IMAGINE

· Classification:

o Added subpixel demo example files which were missing in ERDAS IMAGINE 9.2 [IMG-3326]

· Data Exchange:

o Improved MrSID MG2 and MG3 map projection support by allowing the population of internal WKT strings and writing external PRJ files. [IMG-3148]

o Improved MrSID reading support by implementing reading of MrSID World Files and ESRI Projection Files. [IMG-1107]

o Improved portability of 1-bit TIFF images for use with software products outside of ERDAS IMAGINE. [IMG-1709]

o Corrected error in MrSID file creation that caused problems in Microstation sofware. [IMG-1342]

o A correction for the stagger phenomenon was implemented for AVNIR-2 level 1A/1B1 data. [IMG-3019]

o Expanded ECWs supported projection and map units. [IMG-2540]

o Enhanced Oracle GeoRaster compatibility. [IMG-3229]

· Data Prep:

o Added support for Imagizer Data Prep for Windows Vista. Requires the customer to install the Windows Vista Support Update in conjunction with this fix to take advantage of this feature. [IMG-3029]

o Added non-linear surface creation option to Terrain Prep Tool. [IMG-3286]

o Improved performance of 2D shapefiles with attribute defining elevation in Terrain Prep Tool. [IMG-3313]

· Geospatial Light Table (GLT):

o Improved GLT scale display accuracy, when rotating imagery with rectangular pixels. [IMG-2324]

· ERDAS IMAGINE General:

o Updated the setting of the IREP NITF flag when chipping DTED so they would display correctly. [IMG-2311]

o Enhanced toolkit API: CloseMeasure("nosave") will no longer ask to save the measurements, CloseMeasure() will ask to save measurements. [IMG-2885]

o Add support for Dutch RD projection to ERDAS IMAGINE 9.2. [IMG-2976]

o Improved reliability of Toolkit callback functions [IMG-3284]

o Added support for WorldView RPC in Warptool & AutoSync [IMG-3369]

· Interpreter:

o Introduced a new resolution merge capability, the Subtractive Resolution Merge. [IMG-3295]

· NITF Import/Export:

o Fixes a problem creating JPEG 2000 compressed NITF files that were smaller then 1024x1024 pixels. [IMG-3366]

· Vector:

o Added "Use White Textbox" option to Attribute to Annotation tool. [IMG-3218]

· Viewer:

o Removed the Render outside of View preference in the Viewer Preferences. This feature is no longer needed with today's viewing technology and when on slows down viewing speed. [IMG-3252]

o Corrected the detection of pyramid layers for NITF images with external pyramid layers in support of Dynamic Range Adjustment (DRA). [IMG-2864]

o Fixed IEE functionality. [IMG-3044]

ERDAS IMAGINE Add-ons

· AutoSync:

o Improved the AutoSync Resample Setting Clip to Reference Image Boundary option to more closely clip to the reference image boundary. [IMA-483]

· Radar Mapping Suite:

o Improved support for complex TerraSAR-X (type SSC) data. [IMA-539]

Accessing GeoBase Web Services

GeoBase, the Canadian government portal for free geospatial data, has made several GeoBase layers available as OGC-compliant WMS'. It is also worth noting that the data is free from most restrictions, as stated in the license agreement.

One of the new features in ERDAS IMAGINE 9.2 is the GeoServices Explorer. It is a new way to access web mapping services from desktop versions of IMAGINE and LPS.

Once you login to GeoBase, accessing their WMS layers is pretty straightforward. They send you the WMS service URL in an email, and that's all there is to it... In IMAGINE it is fairly simple to connect - just open a viewer, hit the "open layer" icon, choose a Web Mapping Service in the file type, and then hit the "Connect" button on the bottom right hand side of the interface.

After you hit the "Connect" button the GeoServices Explorer will open (see below). This will list all the WMS layers you can connect to once you have added the GeoBase services. There is a huge wealth of information available in GeoBase. The only thing I couldn't find that I had been hoping for was the SPOT 4/5 data that was made available for download earlier this year. I was able to download the SPOT data but unfortunately just didn't see it as an available layer to connect to...
In the example below I connected to the Canada-wide AVHRR composite - which was a breeze to connect to and display. It was also easy to display other layers such as roads and cities. They also have several layers outside Canada, covering the US, parts of Africa, and a few global datasets. I've included a screen capture of the IMAGINE viewer with the AVHRR data loaded in it.