Open-Source All Sky Camera (OSASC) Objectives

2020 Nov 27 - Brian Kloppenborg

Before continuing my series on the Open Source All Sky Camera (now abbreviated as OSASC), I thought it prudent to step back and discuss what I hope to achieve with this project. As I have often imagined building a company that makes products for astrophysics, I’ve built some commercialization ideas into the project already.

Objectives

I would like a camera that can watch the stars, let me know when there are clouds, and detect bright satellites and meteors. I want the basic capabilities and design details of the resulting product to be fully open source, but reserve the option to make advanced capabilities or features available for purchase in the future. I would also like to have the ability to generate data products (cloud coverage data, meteor streaks, satellites streaks) that could be packaged and sold to third parties.

Business Purpose

Although the basic information and functionality of this product would be open source and free, it is my intent to commercialize this product in the following ways:

• Sell a completely finished and assembled unit.
• Sell a kit which people can finish and assemble on their own.
• Sell additional hardware add-ons.
• Produce proprietary (closed source) extensions which would expand upon the system’s functionality.
• Produce proprietary (closed source) extensions which would permit the collection, reporting, and sale of various observational data to third parties.

Definitions

In the remainder of the document I’m going to use the following definitions:

• Detection – The action or process of identifying the presence of something
• Perform – To carry out, accomplish, or fulfill a specific action, task, or function. It is preferred that all actions are performed locally without a need to connect to cloud-based resources.
• Record – To store data locally.
• Display – To visually present data locally.
• Report – To transmit data to a remote location.

Functional Requirements

These desires translate into the following functional requirements:

• The System shall (001) Detect stars to V~7 over a 90 degree field of view. A wider, 120 degree field of view would be preferred.
• The System shall (002) Perform aperture photometry on stars in real time (an open source, free feature).
• The System shall (003) Record and Display a minimum of two nights of sky images to the user (an open source, free feature). The user should have the option to specify the total number of nights archived. The user should have the option to specify the frequency at which images are stored.
• The System shall (004) Display real time video during daytime or Display the most recent 30 sky images at night time.
• The System shall (005) Detect and Display regions of the sky covered in clouds (an open source, free feature).
• The System shall (006) Record and Report calibrated photometric values on bright stars (a closed source, paid feature).
• The System shall (007) Detect, Display, and Report sky brightness measurements (an open source, free feature) on a nightly basis.
• The System shall (008) Detect and Report streaks from meteors (a closed source, paid feature).
• The System shall (009) Detect and Report streaks from satellites (a closed source, free feature if data contributed upstream; otherwise a closed source, paid feature if data is to stay local).
• The System shall (010) Automatically delete data that passed expiration limits.
• The System shall (011) Ability to Record and Display RAW sensor data for the purpose of debugging and/or error analysis.
• The System shall (012) Ability to Report limited quantities of RAW sensor data for any purpose.

In order to perform these operations, the system:

• The System shall (013) Be connected to a wireless or wired computer network.
• The System shall (014) Be enclosed in a weather resistant container.
• The System shall (015) Be mountable to a metal fence post, wooden fence post, or other suitable outdoor-rated support structure.
• The System shall (016) Be capable of receiving electrical power from AC main source. Optionally, the system could run off of a 12 Volt DC solar-battery system.
• The System shall (017) Be aware of its physical location (latitude, longitude, altitude) and current UTC time to an accuracy below 100 meters and 1-second. These values can be user-specified (free) or provided by GPS (additional cost).

In addition to these requirements, here are a few features which seem like good ideas, but aren’t reasonable to specify as requirements at the present time:

• Some method that simplifies wireless / network configuration.
• The ability to close an iris or raise a shade to protect sensors from exposure to direct sunlight.
• The ability to adjust exposure settings based upon ambient lighting conditions.
• Detect and Report temperature and humidity (additional cost).
• Use temperature and humidity data to engage a heater and fan to keep the dome free of dew. I’m somewhat hopeful that the Pi 4’s CPU, when loaded down with the above processing, will generate enough heat for this purpose.

Next steps

In my next post I will discuss the software architecture I will use to realize these requirements.