POLIS - Public Observatory Location and Information Service

What is POLIS?

As the name suggests, the Public Observatory Location and Information Service provides a directory type of distributed services (similar to DNS) listing astronomical observing sites across the world as well as satellites. Three levels of services are offered:

1. The Observatory Location and Information service describes the Observatory Facilities. It is only updated on demand (automatically, or manually) when there are changes at the facility.
2. Currently known status changes and long-term night by night scheduling and observation reservation system.
3. Real time status changes and observation scheduling, facilitates for observatory to observatory real time communication and collaborative observations.

What is POLIS Provider?

A POLIS Provider is a site, that lists observing sites and strictly complies to the POLIS Standard (formats) and query APIs. To be a valid POLIS Provider, the site must only implement the first level of services. Implementation of the second and third level services is optional. There are 4 types of providers:

• Public sites confirm strictly to the POLIS standard, and provide APIs at least in the JSON format (however XML is preferred for production sites). The site MUST list all known observatories (Earth and Solar system).
• Private sites are used locally by different organisations to support internal infrastructure or as a performance cache.
• Mirror sites are backups of a public sites and should be used only in the case that the public site is down for maintenance or due to technical issues.
• Experimental sites (as the name suggests), are used for implementing and testing new functionality or future unstable versions of the POLIS standard.

Goals

• can list any type of facility: ground based, satellite, mobile, temporary (e.g. solar eclipse),...
• encourages the participation of amateur astronomers and educational organisations (schools, universities)
• open standard, mostly free to use for everyone, but some high-end services (weather monitoring, push notifications) could be available only for paying users to cover related hosting and service charges.
• can be used as datasource for mobile apps as well as for various web UIs and JSON/XML based APIs.
• supports API versions and of JSON and XML formats
• observatories can provide data either manually or with standard APIs
• distributed (no single point of failure). Different sites could provide complete or partial service.

Further documentations

Note: the most current version of the documentation, sketches for new ideas, and different example files can be found in the dev branch.

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How to contribute

• We are working on a list of known to us observing sites, and soon we will start making it publicly available. Of course the information we have is very limited. The best way to keep this information up-to-date is if the people who run the observatories to maintain this information. And of course there are thousands of ground based observatories and satellites that we are not aware of. Please let us know about them, or if you are interested on maintaining the information about them, we will be happy to make available beta versions of tools to perform this task easily. (When stable, these tools of course will be made public domain).
• Currently we are working on a macOS app to manage a POLIS service provider site. The app is in a very early stage (we still do most of the editing with a text editor), but if you are interested on managing a POLIS service site and use a current version of macOS drop us an email at [email protected].
• If you are an amateur astronomer we will be delighted to talk to you! One of our goals is to create a standard, that is opened and useful to everyone. Please drop us an email at [email protected]
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History

The initial idea for a POLIS like protocol was first discussed at one of the HTN (Heterogeneous Network of Telescopes) conferences that took place about a decade ago in Tucson (AZ) and Göttingen (Germany). Initially an agent-based system that negotiates the exchange of observation time was discussed. The idea was to use RTML's Dump mode to describe the current status and capabilities of an observatory and to build a new negotiation protocol.

Around 2012 the StarCluster team developed a very primitive prototype that was able to exchange status information between two imaginary observatories, however further development did not take place.

The idea for such a protocol was reborn in early 2019 when the StarCluster team started working on a new package of astronomy applications. In September 2020 ASA and StarCluster worked together on a joined bid for a new robotic telescope and it was during this period when the decision was made to start a new open source project with the goal to create a protocol and database of modern observatories, which monitor and report their status, and to allow individual sites to negotiate automatically or with human support for observation times and joined observation schedules.

Rick Hessman, University of Göttingen (Germany) coined the name POLIS and introduced the StarCluster team to the work of Rachel Street, who independently developed a database for monitoring observatory statuses.

In November 2020 the ASTRO-Polis project was created on GitHub.