Stitching FAA Sectionals
The following tutorial is written using PhotoShop. There are many other graphics programs capable of doing what is described below. So the following information should still be helpful in learning the techniques used by Richard to Stitch together FAA Sectionals.
By Richard Jackson
Here are the steps I take to stitch together 2 or more VFR Sectional Charts. I use the link below to go to the FAA site where all of the VFR digital sectional charts can be found. I choose the charts I need and select the GEO-TIFF zip file to download to my computer. For this example, I chose Sectionals for Albuquerque and Denver. https://www.faa.gov/air_traffic/flight_info/aeronav/Digital_Products/vfr/
Once the zip file is downloaded, I unzip the file by clicking on it. I select the TIFF file within the downloaded zip file and open it in Photoshop.
The file opens as an Untagged RGB file @300dpi. The first thing I do is convert the Untagged file to Adobe RGB 1998 color space. Convert all VFR sectional downloads to Adobe RGB 1998 color space so that the color of all the maps will match.
I will typically crop out the border of the sectional chart. This makes it easier to overlay adjacent charts.
I create a new image file document sized to the final size of the charts stitched together. Create the new image file in Adobe RGB 1998 color space and choose 300dpi as the resolution. Also chose 8 bit color depth.
Now I can select the cropped each sectional and drag it over to my new image file document. Then one at a time, select and drag each map to be stitched together creating a new layer for each map. Note: Layer’s Tutorial can be found here; https://helpx.adobe.com/photoshop/how-to/ps-layers-basics.html
Once you have all of the sectionals dragged into the new image document, change the Opacity of one of the maps to 50%.
You can manipulate each map individually by going to the Edit drop down, choose Transform, then Transform Rotate. Transform Rotate allows you to rotate one map to line up the LAT/LON lines with another map. You can also move them up/down/left/right by using the arrow keys or clicking and dragging the map for larger moves. Once you have the map in alignment, press the return key to cancel Transform Rotate tool.
This takes some practice, but it works really well.
After I have stitched together the files into one map, I save it as a layered TIFF file in case there are any additions or changes I might choose to make in the future. Then I flatten the file and save it as a PDF. Saving it as PDF will make the file somewhat smaller which makes it easier to transfer or to send to a printer.