IamTechknow / Terraview

Android client for NASA GIBS - a mobile version of Worldview

Terraview

Terraview is a REST client for NASA's Global Imagery Browse Services (GIBS). GIBS is a public API providing access to satellite data and imagery from the EOS (Earth Observing System) and A-Train satellites. While this application is not directly related to NASA's Worldview, I worked on improvements on the project in an internship in NASA's Goddard Space Flight Center and created this based on the idea a better interface could be made for mobile devices.

Highlights

• Implemented with MVP (model view presenter) architecture, with ViewModel to persist current data. MVVM implementation in separate branch
• Google Maps API used to present web tile imagery from GIBS
• Room library used for database and to create many-to-many relationships among the data
• Retrofit 2 used for networking to convert JSON and XML endpoints to ordinary interfaces
• RxJava used to implement an event bus and to coordinate asynchronous queries with Room and Retrofit APIs
• TapTargetView used to create a simple app tour
• RecyclerView list with support for dragging and swiping items
• Visualization of Colormaps for supported overlay layers
• Autocomplete search feature for layer picker UI with custom ContentProvider
• Metadata is obtained and parsed from Worldview, licensed under NASA's open source license

Testing Highlights

• Unit tests for the Presenters and instrumentation tests for Room data access objects (DAOs)
• Espresso tests for the map and animation dialog UI (more in MVVM branch)
• Mockito framework used to mock the Views
• Mockito doAnswer-when idiom used for mock implementation of Retrofit APIs
• Dependency injection throughout the app to make testing viable

Screenshots

Libraries

• Android Architecture Components
• Google Maps API for Android
• RxJava 2 and RxAndroid 2
• Retrofit 2
• Simple XML
• Gson
• OkHttp3
• Espresso
• Mockito
• TapTargetView

Requirements

To build, replace the API key value with your own API key. You can run the included tests without a key.

Helpful Tutorials and samples I used:

• RecyclerView drag and swipe tutorial
• TODO-MVP samples
• Event Bus with RxJava tutorial
• Android MVP Unit Testing
• Testing RecyclerView with Espresso
• RxJava Android Samples
• GithubBrowserSample
• GIBS API for Developers

Acknowledgements

We acknowledge the use of imagery provided by services from the Global Imagery Browse Services (GIBS), operated by the NASA/GSFC/Earth Science Data and Information System (ESDIS, https://earthdata.nasa.gov) with funding provided by NASA/HQ.