About
GOAL:
Our goal is to provide scientists and learners of all ages with an affordable, accessible, and widely distributed instrument suite that permits a greater understanding of Earth science remote sensing technology and applications through spectral observations and data collection.
To achieve this goal, we designed the instrument suite with inexpensive COTS (commercial off the shelf) components. The STELLA team has created detailed documentation and build instructions, software, as well as a collaborative open GitHub forum. Finally, the team created a simple STELLA dataviewer to allow users to visualize and analyze their data in real time.
HOW IT WORKS:
The STELLA instruments use COTS sensors connected to a micrcontroller to measure incoming solar radiation, light reflectance, air temperature, surface temperature, methane and more, dependant on the STELLA instrument built. STELLA-1.2, which is the newest additon to the suite, is designed to support a wide range of customizable sensor packages.
Each instrument records data to a micro SD memory card. Measurements include important metadata such as, a time and date stamp and a data batch number. To improve accessability and usability, the instrument operating system is written in CircuitPython, a beginner friendly, open-source version of the Python programming language. Software proficiency is not required: Drag-and-drop the files to program the instrument so that it is ready to go!
VERSIONS:
There are currently six different versions of the STELLA instrument to accommodate differing interests and needs. The STELLA-Q2, Helio-STELLA, and STELLA-AQ versions are built entirely with connectors, no soldering is needed. This version is ideal for students because the instrument is ready to use without skilled technical assembly. Soldering and 3D printing are needed to assemble the STELLA-1.1, STELLA-1.2 and STELLA-2.0. Versions STELLA-1.1 and STELLA-2.0 can be easily adapted to drone use, weighing in at less than 100 grams. The STELLA-1.1, and the newly updated version STELLA-1.2, use a color display screen with touch-response controls. The STELLA-2.0 communicates by BlueTooth to a smart phone, using the Adafruit Industries Bluefruit Connect app for iPhone and Android. The STELLA-1.2 once fully developed will replace the STELLA-1.1.
APPLICATIONS:
STELLA instruments can be readily adapted to use other sensors, to accommodate a variety of applications and to engage a wider audience. For instance, a soil moisture probe could be added to support farming and agricultural production, or air quality sensors could be integrated to aid citizen scientists in collecting data environmental assessments. A 3D printed attachment for the STELLA-1.1 and 1.2 supports cuvettes, allowing the spectral sensors to measure the transmissivity of liquids. The STELLA open forum contributes to potential new instrument capabilities by fostering collaboration between scientists, engineers, educators, students, and other enthusiasts. The functional versatility of STELLA will allow it to become an immensely valuable educational and scientific tool that encourages an improved understanding of the status and health of the Earth’s physical environments and ecosystems.