In a previous post, we shared ideas about key elements that make great maps according to our friends at Map the Xperience. They presented a webinar on the subject, so we poached their ideas for Part 1 of this blog discussing the importance of map quality and connecting with the user. In Part 2 we’ll expand on the other two elements, Presentation & Design, and Accuracy.   

After identifying the target audience and deciding on the level of detail required, putting all of the relevant data on a map while keeping it readable is a challenge. Good maps document what the reader needs to know at a basic level to prevent getting lost. Great maps highlights what the reader needs to know to fully experience the mapped area.  It all starts with map accuracy and the readability imparted by the presentation and design of the information.

Presentation & Design

A map quickly becomes cluttered as additional layers of data are added so how do you present all of that in a way that doesn’t make people’s eye’s pop out? It pays to have some knowledge of design, or get some advice from someone who does. Can you use colour to convey any of the information on the map, and is the colour scheme pleasing to look at? Do the symbols make sense to anyone but you? Are they simple and not open to interpretation? Can shading or patterns be used to highlight map features? Map The Xperience takes the design process very seriously and highlights their 3D hillshading as one of the features that make their maps unique.

An equally important part of the discussion about presentation includes thinking about how and where readers will use the map. Is it in paper format or digital? Will they be reading it thousands of feet in the air in a hot air balloon, at a table studying the map with a group, or on a tablet in the middle of a forest?  Anticipating how a map will be used helps to make design decisions such font and symbol sizes, label placement, and the use of legends.

Accuracy

What’s the point of a map that isn’t accurate? This is obvious and yet still worth mentioning. While lots of lovely art is made by taking liberties with the accuracy of map elements (that’s another blog post) maps for specific activities need to be accurate – spatially and in the supporting information. This can mean field testing maps in the way that Mapsynergy tests its ski resort maps by actually skiing the hills, and New York-New Jersey Trail Conference constantly updates maps according to data collected by its members and staff. It can also mean augmenting physical data with local knowledge. Rhonda Lerner visits each of the businesses listed on her tourist map to verify that the the are tourist-friendly and current. Pixmap Cartografia Digital researches the local names for locations on their maps of Argentina and Chile, because in the end, who can knows a place better than the people who live there.

In summary, good maps are functional while great maps add to the experience of visiting a place by being, all at once, informative, accurate, easy-to-use and pretty to look at. It’s no easy feat to meet all of those criteria. Perhaps the pursuit of the perfect map is the reason why cartographers are so passionate and dedicated to their craft.

The Channel Management tool in Geographic Imager is excellent for quickly making false-color composites from multispectral images in Adobe Photoshop. In this blog, we’ll take a look at Channel Management and see how it can be used on LandSat 8 imagery.

Most satellite providers supply a tile or scene as several images while each image captures a different wavelength of the satellite’s electromagnetic spectrum. The LandSat 8 satellite instruments measure in the visible, near-infrared and shortwave infrared portions of the spectrum. Its images have 15-metre panchromatic and 30-metre multi-spectral spatial resolutions. Here is a list of all LandSat 8 band names, bandwidth, and resolution.

Band # | Type Bandwidth (µm) | Resolution (m)

• Band 1 Coastal Aerosol | 0.43 – 0.45 | 30
• Band 2 Blue | 0.45 – 0.51 | 30
• Band 3 Green | 0.53 – 0.59 | 30
• Band 4 Red | 0.63 – 0.67 | 30
• Band 5 Near Infrared (NIR) | 0.85 – 0.88 | 30
• Band 6 SWIR 1 | 1.57 – 1.65 | 30
• Band 7 SWIR 2 | 2.11 – 2.29 | 30
• Band 8 Pan | 0.50 – 0.68 | 15
• Band 9 Cirrus | 1.36 – 1.38 | 30
• Band 10 TIRS 1 | 10.6 – 11.19 | 30 (100)
• Band 11 TIRS 2 | 11.5 – 12.51 | 30 (100)

Before starting, you can download some sample LandSat 8 imagery here and follow this tutorial.

To create different band combinations, we’ll first need to combine images into one image and then use Channel Management to assign band combinations.

1. In Adobe Photoshop, open all of the 30-metre resolution images:

• Band 1 – Coastal Aerosol
• Band 2 – Blue
• Band 3 – Green
• Band 4 – Red
• Band 5 – Near Infrared (NIR)
• Band 6 – SWIR 1
• Band 7 – SWIR 2
• Band 9 – Cirrus

When using Landsat 8 imagery, file names have a _B and the band number as a suffix (e.g. LC80450292013225LGN00_B1.TIF). Note that Band 8 wsa not used because it is has a different resolution.

Now that the band images are open, we can continue to combine the images into a single image using the Adobe Photoshop Merge Channels feature to store the spectral information. Each channel is grayscale which can be used to store different information.

2. Go to View > Channels to open the Channels panel. In the panel options menu, select Merge Channels. In the Merge Channels dialog box, the Mode will automatically default to Multichannel because there are eight channels. Click OK.

The Merge Multichannel dialog box will immediately appear. In this dialog box, we’ll specify each image to use for each channel. It’s very important to assign a channel to the according image. In this case, the naming convention of the images makes it easy because the images are in the correct order. In addition, when combining multiple images, it is good practice to ensure that all the images have the exact same image size and are georeferenced the same.

3. Notice the “Specify Channel 1” text, you’ll assign the Band 1 image to it. Click the Image drop-down to display all the images that are compatible to be merged. Select the first image which ends in _B1.tif and click the Next button. For “Specify Channel 2”, select the image ending with _B2.tif and click Next.

4. Repeat the steps for the remaining images until all eight channels have been assigned an image, ensuring the channel number matches the image band number. The only exception will be Channel 8 which uses Band 9 – Cirrus (_B9.tif) because we didn’t include the panchromatic band 8 which has a higher resolution and different georeference.

The images are now merged into a single image in Multichannel mode. Since an image in  Multichannel mode is not compatible with Geographic Imager, it will have to be converted to Grayscale mode.

5. Go to Image > Mode > Grayscale. This will assign the first alpha channel (Band 1 – Coastal Aerosol) to use the Grayscale colour space.

6. In the Channels panel, rename all the channels to their corresponding bands.

• Alpha 2 -> Band 2 – Blue
• Alpha 3 -> Band 3 – Green
• Alpha 4 -> Band 4 – Red
• Alpha 5 -> Band 5 – NIR
• Alpha 6 -> Band 6 – SWIR 1
• Alpha 7 -> Band 7 – SWIR 2
• Alpha 8 -> Band 9 – Cirrus

Renaming channels makes assigning band combinations easier in later steps. It is recommended to save this image as the source for all band combinations and use Save As to create a new images when saving band combinations.

7. In the Geographic Imager panel, click the Channel Management button.

The Channel Management dialog box shows the current colour mode is Grayscale.

8. Change the Color Mode to RGB Color.

Now the fun begins, we can easily create any band combination. A traditional color infrared image (CIR) is band combination 5-4-3. This refers to what band is assigned to the RGB channels, respectively. CIR is good at determining the health of vegetation; the cell structure of leaves strongly reflects near-infrared light and the stronger the light sensed, the healthier the plants are.

8. Assign Band 5 as the Red channel, Band 4 as the Green channel, and Band 3 as the Blue channel.

9. Click OK to complete the process.

We now have a image which can be used to determine healthy vegetation which is shown in bright red. This makes it easier to determine different types of vegetation making it easier to identify crops and wetland.

Some other common Landsat band combinations are:

• Natural Color: 4-3-2
• False Color (urban): 7-6-4
• Color Infrared (vegetation): 5-4-3
• Agriculture: 6-5-2
• Atmospheric Penetration: 7-6-5
• Healthy Vegetation: 5-6-2
• Land/Water: 5-6-4
• Natural With Atmospheric Removal: 7-5-3
• Shortwave Infrared: 7-5-4
• Vegetation Analysis: 6-5-4

Another band combination of 6-5-2 can show how healthy vegetation is.

10. Use the History panel to go to the previous step.

This will reset the Channels so that another band combination can be configured easily.

Another great way to make non-destructive edits is to use Adobe Photoshop adjustment layers. Adjustment layers layer can be used individually or in combination to adjust settings such as levels, exposure, contrast, brightness, hue, and saturation to make it easier for the human eye to identify features. It is not recommended to alter an images resolution if it is going to be used in third-party remote sensing software.

There are several options when saving an image like this and it depends on whether you want to maintain the channels or not. When the channels aren’t needed, GeoTIFF is a popular format and is compatible with most spatial software applications. In the TIFF save options, you can uncheck the option for Alpha Channel and Spot, which will prevent saving the alpha channels and will create a saved copy. You can also simply save it as a PSD file (a default reference file will be created) and with all the alpha channels intact. Note that including channels will increase the size of the file.

June 18th is #InternationalSushiDay, and as they say “You can’t buy happiness, but you can buy sushi, which is kind of the same thing.” Sushi has become so mainstream that you can find a sushi restaurant almost anywhere. With the wide variety of ingredients and flavours available in maki rolls, sashimi and sushi, no wonder it’s such a popular meal. To celebrate, we made a map! Instead of focusing on Toronto this time, we went to the west coast to highlight some restaurants in Vancouver that have ‘Bucket List’ sushi. These restaurants were chosen from this Narcity article. While not all of them are featured on the map, the 12 restaurants shown are still serving bucket list sushi items! If you try any of these, please leave a comment! Interested in how we made our sushi map? Keep reading!

The City of Vancouver has a great open data portal, which is where we pulled the part of our data. 

We got our street and park files from the portal, and created the sushi points using the MAP Point Plotter (one of my favourite tools!). Using the restaurant addresses provided in the article, we plotted each of the points on the map.

Once all of our points were in, we used a MAP Theme to style the streets. Ours looked like this:

Once the streets were styled, and colours were chosen it was time to style the rest of the map. We put a land mass file in to give boundaries, and show the coast line.

We styled the restaurants with different pieces of sushi, and included their addresses for easy reading. But, the most important feature and point of this map, were the bucket list sushi items that each of these restaurants serve. To show those featured menu items, we added them to the MAP Attributes (and included their Yelp rating, along with a photo of food from their restaurant).

Once those were in, we used the MAP Web Author tool to make the map interactive! When you view the map and click on the sushi icon for each of the restaurants, you’ll see the restaurant name, the bucket list sushi item, the Yelp rating, and a picture of their food. Here’s what our Web Tags look like.

Here’s what the final map looks like! If you click on the sushi pieces, you’ll see the tags we created in MAP Web Author. Interested in the PDF? It’s also linked below. We’ve put the Adobe Illustrator file up as well, if you’d like to take a look or play with the map itself! Happy #InternationalSushiDay!

Download this map so that you can play with it in MAPublisher.

View it as a PDF here.

For the majority of Avenza Maps users, layers are indispensable. Not only are layers a repository where placemarks, tracks, and photos are stored, but they also enable you to both manage and share map feature data.

With the release of Avenza Maps 3.5, Android users will be introduced to a feature that was previously only available on the iOS platform, the Layers tab. The Layers tab is an invaluable resource which provides a complete listing of all layers in the app database, including their existing map associations. But what is most exciting about the Layers tab is it’s new ability to export layers. Exporting layers from the Layers tab will streamline data archiving. From the Layers tab, you now have the ability to export an individual layer, multiple, or all existing layers in one fell swoop.

Let’s see just how easy it is now to archive your map feature data.

Say we had two topographic maps. One map contains two layers while the other has three separate layers. Below is an example of how all five layers can be exported from the Layers tab at once.

iOS

Android

If you plan on importing your exported data back into the app, it is important that you export to either the KML or Shapefile (requires a Pro subscription) formats. Once you have tapped on Export, navigate to the storage location and tap Upload (iOS) or tap the check-mark icon (Android) to export. All of your layers will be exported to a single file for archiving. If you wish to restore these layers at a later date, you can simply import them back into the Layers tab and all layers will appear in the layers tab as they did prior to export.
The following example is very similar but this time we are only exporting a selection of layers from the Layers tab.

iOS

Android

When it comes to exporting map feature data from multiple maps, the Layers tab is now clearly the most efficient method. A word of caution, if you are exporting large amounts of map feature data, it is advised that you break your export up into separate files as opposed to saving all of your layers to a single file. If you are exporting to email, there are restrictions to the size allowed for file attachments. Additionally, when exporting large files, there are resource limitations that may come into play and which vary by device and work environment.

Your data is a valuable resource. Countless hours can be devoted to data collection and the resulting map features are vital to the completion of your work projects. For most, it is extremely important to regularly export data for backup or archiving. Exporting layers from the Layers tab has just made this process that much easier.