Top 3 Secrets to Geotagging Successfully

Geotagging failure at Japan's most famous temple in its #1 sightseeing city, Kyoto.

Though it could be argued that Kyoto's Kiyomizudera in Japan, the most famous temple in the entire country is at least in the general vicinity of this incorrectly geotagged photo, it's definitely not in the dense forest shown here. A quick check by the photographer with an online map or geotagging software map would have made this error immediately obvious. This geotagging failure and thousands like it can be found all throughout Google Earth via its Panoramio photo overlay.

If people cannot correctly geotag their photos taken in Kyoto at Kiyomizudera, Japan’s most famous temple in the country’s #1 most popular sightseeing city, a site that is clearly marked on every single map a person would be using for their travels in Kyoto, you might be tempted to ask what possible hope can there be for geotagging?

Geotagging is not and never will be a good choice for the casual and non-attentive hobbyist, unless results like those pictured in this post are good enough for the said casual and non-attentive hobbyist. However, for those who are willing to take a little care with their geotagging efforts, incredible accuracy is easy enough to achieve.

  1. POWER UP EARLY - Turn on your GPS datalogger or GPS equipped camera as soon as you can before you need to shoot. This may at first seem obvious because with any experience geotagging you quickly learn that the initial location acquisition can take a minute or more after powering up. But when the signal is weak or seemingly non-existent, it becomes even more important to power up early. Though the unit may have trouble acquiring a position when there is no direct line of sight to at least 3 GPS satellites, often a GPS datalogger, GPS camera, or other GPS device will eventually make a best guess at where you are from weak signals. The data is much less likely to be accurate when the signal is weak, but by getting something, even a frantic zigzagging line around the general area you were in or erratic coordinates on photos all taken in the same general vicinity, is still better than nothing. It will give you clues as to where you were and make it much easier to manually correct the positions using geotagging software with maps once you get home.
  2. TAKE MORE PHOTOS – Even if your GPS device doesn’t lock on until after you change position and after your photos are already taken, take a couple more photos once you notice your device is acquiring GPS data again (even if there is nothing you really want to photograph). Having something logged in the vicinity and around the same time makes it much easier to figure out where you were when working with maps to shift locations manually in your geotagging software.
  3. GPS SIGNALS ARE NOT REQUIRED TO GEOTAG – When all else fails and as an additional assist when you have no signal, you can simply take photos of your surroundings to document where you are. There is not always a corner street sign to turn to and snap, but there will be something. And if you are in a remote wilderness area, photograph in multiple directions around where you are standing to have photos that can help you manually correct GPS data once you are home and using maps to tag your photos. Even photos with no corresponding GPS data can help immensely. You can look at what you photographed from above using detailed satellite images and compare and find the pieces of the puzzle you need. If you are in dense vegetation in a ravine and there is absolutely nothing noteworthy to photograph for referencing on a map (as has happened to me more than a time or two), once you get into a clearing or on higher ground, take some more photos after you get a lock. Those clue photos can be invaluable later when you manually adjust the coordinates on your real photos.
Camphor trees, known as kusunoki in Japan, can be found at the entrance to Shoren-in, a temple on Kyoto's east side.

Another geotagging failure that could have been avoided by making a quick check before uploading. I happen to know this tree. It's an ancient camphor tree next to the entrance of Shoren-in, a temple on the east side of Kyoto. I'm sure the photographer was not trying to incorrectly draw attention to the corner of a small, barren neighborhood park as has been done with this incorrectly geotagged and untitled photo viewable on Google Earth and Panoramio. This park is also on the east side, but far more than a stone's throw north of Shoren-in.

Geotagging is simply the process of adding location data to photos. Instead of fretting over loss of signal when shooting, we must accept that geotagging is a pursuit that requires a little cleverness and forethought on our part to achieve the highest levels of success and accuracy.

Of course, if you are not as obsessive about accuracy as I am, you could just accept whatever you end up with from automation and say to yourself, “It’s good enough.”

But I will tell you there are some dramatically off the mark geotags on photos online (Panoramio, Google Earth, etc.) and I encourage you to avoid being one of the all-too-common geotaggers out there who don’t make an attempt at accuracy with their tags.

If a person is not willing to try to geotag their photos accurately, why bother to geotag at all? Just as you might find it slightly annoying to encounter a photo online that is not tagged correctly, your friends and others will not be impressed by your efforts to share location data if the data is perceptibly wrong.

I know Kyoto better than any other city in the world. I even know it better than my hometown. I bike through the large and small streets of Kyoto, Japan 20 to 30 miles a day (some days much more) almost every day I’m there. The number of inaccurate tags on photos taken in Kyoto is not small. I only know this because I know that city so well, but I’m sure the problem is just as bad everywhere.

I’ll conclude this post by repeating the question I posed 2 paragraphs earlier…
If a person is not willing to try to geotag their photos accurately, why bother to geotag at all?

Dan Savage [email]

Images:
First – The small red gate in this photo is one of the entrance structures at Kiyomizudera, not the main temple building. The Dragon Fountain at the top of the geotagging project site, Living in Japan – 3 Months at a Time, was taken just a short walk behind this red gate.
Second – Joudoji park where this geotagged photo incorrectly indicates the giant Shoren-in camphor tree can be found. This picture of the Philosopher’s Path (Tetsugaku no Michi) on the Savage Japan Podcast website, taken near where I live in Kyoto, shows a spot on Tetsugaku no Michi just a few yards east of Joudoji park. Though Joudoji park by itself is not very exciting and there is no giant camphor tree, community family events and other distinctive activities take place there. I sometimes pass by and find an interesting event underway. At the Living in Japan geotagging photo site, I’ll be posting images already taken at both Joudoji Park and the Shoren-in temple.

Share

GPS Geotagging Basics - What are we doing?

Back of a Holux M-241 GPS wireless data logger, my first GPS device.In a Nutshell
Geotagging involves recording your position in the world on a time line using coordinates obtained from some of the 24 GPS (Global Positioning System) satellites orbiting the earth. The information is acquired and saved in a log file using a GPS capable device. The acquired data can identify precisely where you were at specific times during the period you were logging your positions.

A signal from 3 different satellites must be accessible to the GPS device you are using to triangulate latitude and longitude. With 4 satellites, altitude can also be determined.

Before recording a position time line, it’s important to synchronize your camera’s clock to the clock in your GPS datalogger. With the clocks synchronized and the time and date being saved to each photo’s EXIF file (Exchangeable Image File Format) by your camera, software can then later be used to match the times and add the appropriate GPS coordinates from your GPS device’s log to each photo’s EXIF file.


Summarizing in Layman’s Terms

The camera knows what time the photo was taken and that information is already embedded in the photo’s hidden data field. The GPS data logger records where you are (and what time you were there) constantly when it is activated. Software has been written to look at the photo and the GPS log file to match the times and then copy the appropriate location data from the GPS log file to each photo’s hidden data field.

There are a few cameras available now with built-in GPS capabilities that can be set to include GPS coordinates in the EXIF data automatically. Also, many smart phones such as the iPhone and its competitors provide built-in GPS capabilities, and much of what is discussed on this site will be of interest to smart phone geotaggers. I also plan to test smart phone geotagging features and trail map apps in the future.

But for high quality photographs, most of us in the near future will be relying on GPS dataloggers that stand alone or attach to a camera for generating the time synchronized GPS coordinates necessary for geotagging our images.

There are software tools and photo websites that facilitate adding location data to pictures taken without GPS data logging. I’ll also discuss my experiences with those options, but my priority has been to develop proficiency with “real” geotagging, generating and logging more precise geographic information in real time as I shoot.

Instead of worrying too much today about how we are going to merge the location data with our photographs, let’s focus on first things first. What are we going to use to accumulate and log the GPS data needed to geographically tag our photos?

In the next entry I’ll discuss the Holux M-241 GPS datalogger, my first GPS device.

Dan Savage [email]

Important: If you are new to GPS reliant activities, keep in mind that GPS data acquisition is limited by geography and physical obstacles. Architecture, natural features, and being indoors can all inhibit acquiring a position. I’ll be writing more about how to work around those limitations in future entries.

Image: Photo of the backside of the compact Holux M-241 taken on my deck in Colorado. That’s Red Peak at the southern end of the Gore Range in the background. The Holux M-241 GPS datalogger measures 1.26″ x 1.18″ x 2.93″ (32.1 mm x 30.0 mm x 74.5 mm).

Share