Retaining the location information in your ground photographs in mapping
Mapping your photographs often is the starting point for investigating what you have gathered in the field--water quality, invasive species, historical homes, number of pedestrians or vehicles at intersections, weather, and much more. ArcGIS (Online and Pro, plus apps such as story maps) provide many options for you to automatically make maps from photographs you have taken in the field. Coupled with these photographs is often attribute information about tree height and species, type of litter, dissolved oxygen in water, noise level, our notes capturing our thoughts about the place, and a whole host of other information that can be displayed in popups, tables, or in other ways.
One of the easiest ways to map your photos is to create a Map Tour in a story map, as described here with one of my photos shown below. Another way is to use the Photos with Locations tool to quickly map a whole folder of photographs, as I describe here.
However, for the above methods, or for any other method to work, first, your photographs need to contain the location where they were taken for these maps to be created. How can you make sure that your photographs' locations are retained so they can be mapped? On most modern devices--phones and cameras--there is a setting that you need to make sure that your location information is included in your photographs. This may be called "location" or "GPS" or even "map" and is sometimes under privacy settings. For example, on an iPhone, it is found under Settings > Privacy > Location Services. Then, scroll down in the list of applications and make sure that Camera is set to either "While Using" or "Ask Next Time". No matter what device you use, you want to make sure that the location information is captured when you take photographs. This is often stored in an EXIF file, which provides specific information about photographs, like the camera settings, time and date, and location where a photo was taken (usually given in a latitude-longitude format). This file can be edited, which is beyond the scope of this essay, but usually you don't need to do so; just make sure the location is captured.
Let's say you took a bunch of photos without having the location services on. No problem. With many tools in ArcGIS Online, ArcGIS Pro, and in story maps (for example in the Map Tour I mentioned above), you can manually place each photo on the map. In addition, before you even map your photos, there are online tools and programs that can write location information for locations you specify into the photograph's EXIF file (I have used https://www.geoimgr.com/ for many years for this purpose).
Second, during your workflows of transferring your photographs from your phone or camera to ArcGIS Online, you need to make sure that the location information on the photographs is not lost. How can it be lost? Depending on whether you email the photographs to yourself, upload them to a cloud drive, or post them on social media, or even cable the photographs to your computer, the location information may be stripped off. Some of these tools embed your photograph and thus do not retain the location or any other metadata. You'll know right away when this happens, because your photographs won't be placed on your map, or else they'll be at "Null Island" off of West Africa at 0 degrees latititude and 0 degrees longitude. When this happens, turn it into a teachable moment: Why is this photograph not mapped at all or in the middle of the ocean? But to avoid this situation, you will need to troubleshoot your workflow and decide for you what is the best method to ensure the location information is retained.
Can you check the photographs before you map them and thus know ahead of time? Yes, you can click on the images and access properties > details (on a PC, the procedures might be slightly different on a Mac). As shown below (for photograph #2 attached to this essay), the GPS latitude-longitude information is shown, roughly at 37 degrees north latitude and 108 degrees west longitude:
One wonderful set of reflections and discussions that such mapping of photographs entails is "how spatially accurate is that photograph?" Is it within 2 meters of your actual location, 10 meters, or something more, and why? What are your accuracy requirements? How could you improve the photo locations? And furthermore, on what are you basing your comparisons or "true" location? You may be using a high resolution image as your basemap. But even imagery from aircraft, UAVs, and satellites are cast onto map projected surfaces and need to be used with care, as well, as I explain here and here.
In a recent institute in which I was instructing called Indigenous Voices, the educators and I took a lot of photographs in the Four Corners area in the southwest USA during the field trip components of the institute. I tested different methods with my own devices and workflows and want to share the results with you. Again, you will have to determine what works best in your instructional setting, but I hope my testing is helpful.
Attached to this essay are 5 versions of the same photograph that I took, for you to test them yourself if you would like. Each began as a single photograph with the location services turned on. I took the photograph in front of the Cortez Cultural Center (wonderful place for the inside portion of our institute!) but I used different methods to transfer the photo from my device (iPhone 11) to my computer (PC). Photo #1 (aaa1phototest) is one I emailed to myself from my phone's photo gallery using the default email client, which in my case I set up for gmail. The location information was lost upon my receipt of the email. Photo #2 is one that I emailed to myself from my phone's photo gallery using the Outlook mail client. In this case, the location information was retained. I sent photo #3 to myself not from the photo gallery but from my phone's Outlook mail client, and chose the photo as an attachment, but here, the location information was lost. Photo #4 is one I uploaded to a cloud drive (in this case, OneDrive), and downloaded to my local device, and the location information was retained. By the way, my photo in OneDrive was in .HEIC format. I wanted to map it so I converted it to .JPG, and the conversion thankfully did not remove the location information.
Photo #5 is one I tweeted, but no matter if I use the Twitter URL in my ArcGIS Online maps or story maps (which is: https://pbs.twimg.com/media/FV8wzduUsAE1y7_?format=jpg&name=small) or if I downloaded my tweeted photo to my device, either way, the location information is not there. Why? In this case, it is because I have my privacy settings for Twitter set so that my precise location is not revealed. If I wanted to turn that setting on, I could using these procedures. The same holds true for other social media--Facebook, Instagram, and so on--you have to opt in to retain the location information, and such choices are loaded with pros and cons, as I discuss in this UCGIS Body of Knowledge chapter.
Working with GIS, maps, and photographs involves software, operating systems, and devices--all of which are simultaneously and rapidly evolving. Regard these guidelines as a set that will need to be updated as these tools--and our workflows and educational practice--move forward. In my way of thinking, Photo #3 should have had location information retained. Working with these tools is a reminder that we need to pivot as needs and tools change, but is part of the "be a lifelong learner" mantra that we model for our students.
