add OpenTopography credits

README.md

@@ -168,6 +168,10 @@ The end goal of this project is to enable UAS operators to perform terrain-rayca
 If you're interested in contributing to this project, feel free to make a fork. This project will
 follow the [fork and pull model](https://reflectoring.io/github-fork-and-pull/) for third-party contributors.
 
+
+
+
+
 ### Cloning this project with submodules
 This project requires content from other git repositories (such as Theta's [DroneModels database](https://github.com/Theta-Limited/DroneModels)) to build correctly.
 
@@ -187,6 +191,51 @@ If you wish to update the contents of submodules from their source:
 git submodule update --remote
 ```
 
+### OPENTOPOGRAPHY_API_KEY in local.properties for DEM downloading
+
+The OpenAthena app's automatic DEM downloading feature requires an Application Programming Interface (API) key from OpenTopography.org ([obtainable here](https://opentopography.org/blog/introducing-api-keys-access-opentopography-global-datasets)) to function. Such an API key authenticates the app with OpenTopography's servers for DEM downloading. A default key will be automatically included in releases from the Google Play or Apple AppStore; however, you will need to obtain one for yourself if you clone this project's code from GitHub or download it from F-Droid.
+
+#### Add your OpenTopography API key from within the OpenAthena app
+This capability is not yet present.
+
+#### How to Acquire and use an OpenTopography API Key for building this project
+
+Follow the instructions in the link below to obtain an API Key for OpenTopography.org:
+
+[https://opentopography.org/blog/introducing-api-keys-access-opentopography-global-datasets](https://opentopography.org/blog/introducing-api-keys-access-opentopography-global-datasets)
+
+After cloning this project, edit the file `local.properties` which is auto-generated by Android Studio in the root directory of the project. It should have appearance similar to below:
+```bash
+## This file must *NOT* be checked into Version Control Systems,
+# as it contains information specific to your local configuration.
+#
+# Location of the SDK. This is only used by Gradle.
+# For customization when using a Version Control System, please read the
+# header note.
+#Tue Jun 14 14:32:24 EDT 2022
+sdk.dir=/home/YOURNAME/Android/Sdk/
+```
+
+Add a new line to the end of the `local.properties` file:
+```bash
+OPENTOPOGRAPHY_API_KEY=nlhhp3yd9ud54tr3eem4akqv49wcb23i
+```
+
+
+...replacing nlhh...23i with the OpenTopography API key you obtained from the above link
+
+
+You will then be able to build the project and the API key will be included in the app.
+
+
 # Acknowledgements
 
 This software project would not be possible without the tireless work of many U.S. public servants and open source maintainers. Please see [CREDITS.md](./CREDITS.md) for a full list of included software libraries, and their authors and licenses.
+
+
+Version v0.21.0 and later of this software use services of the website OpenTopography.org for DEM downloading within the app. The privacy policy of this website is available below:
+
+https://opentopography.org/privacypolicy
+
+
+OpenTopography is operated by the University of California San Diego with support from the National Science Foundation. It is not affiliated with the OpenAthena project.

app/src/main/java/com/openathena/AboutActivity.java

@@ -80,8 +80,9 @@ protected void onCreate(Bundle savedInstanceState) {
                         + "<a href=\"https://github.com/agilesrc/dem4j\">agilesrc/dem4j</a> Apache-2.0 license<br>"
                         + "<a href=\"https://github.com/ThreeTen/threetenbp\">ThreeTen/threetenbp</a> BSD 3-Clause<br>"
                         + "<a href=\"https://github.com/apache/commons-lang\">Apache Commons Lang</a> Apache License<br>"
-                        + "<a href=\"https://github.com/apache/commons-io\">Apache Commons IO</a> Apache License<br>"
-
+                        + "<a href=\"https://github.com/apache/commons-io\">Apache Commons IO</a> Apache License<br><br>"
+                        + "This project uses services of the website OpenTopography.org for DEM downloading within the app. The privacy policy of this website is available here: <a href=\"https://opentopography.org/privacypolicy\">https://opentopography.org/privacypolicy</a><br>"
+                        + "OpenTopography is operated by the University of California San Diego with support from the National Science Foundation. It is not affiliated with Theta Informatics LLC or the OpenAthena project."
                 ,0,null, null)
         );