Definition of two new international standards for:

A) Telescope Visibility

We define the term "Visibility" as a time interval when a given telescope can observe a given set of coordinates during a given time interval. The visibility is limited by constraints such as the ability to only observe during night. Most telescope operators provide a public tool that can be used to find out at which times a given target can be observed, but the input and output formats are diverse.

Latest Draft of Protocol definition:
https://www.ivoa.net/documents/ObjVisSAP/index.html

B) Observation schedules

Many telescope operators operate public access to their archives via which information of observations (e.g. coordinates, start-stop times) can be found out. Also, information about future observing plans is sometimes publicly accessible but, again, in diverse input and output formats which we also propose to standardize.

Final Protocol Definition: 

https://www.ivoa.net/documents/ObsLocTAP/index.html

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Objective

Our long-term goal is that all telescope operators will make these two types of information accessible via a service based on URL queries with standardized electronically readable output. This way, tools can be developed that obtain all relevant information in a uniform way from many telescopes, for example, to determine intervals of common visibility for a given target which would be an important element for multi-messenger coordination.

The team

Matthias Ehle, Aitor Ibarra, Erik Kuulkers, Peter Kretschmar, Jan-Uwe Ness, Emilio Salazar, Jesus Salgado, Celia Sanchez Fernandez, Richard Saxton

 

Work Steps

1. Formulation of protocol (Done)

The requirements (compliance criteria) for the services are written in IVOA (International Virtual Observatory Alliance) documents. We have started with an initial formulation and have then continuously iterated the document descriptions. The most recent versions can be accessed via

A) Visibility: ObjVisSAP Protocol description in IVOA

B) Observation Times: ObsLocTAP Protocol description in IVOA

2. Consultations with international partners (Done)

To reach our goal that only one protocol will be used to publish visibility and observation times, the protocol formulation and compliance criteria need to be realistic and sufficiently generic for a large diversity of observatories to be followed.

We have invited to a Workshop at the European Space Astronomy Centre near Madrid, Spain, see Workshop web page.

  • The participants and their institutions were introduced in this presentation
  • The proposed protocols were introduced in this presentation
  • Detailed Minutes contain what has been discussed and concluded.

3. Presentation of our concepts in international Meetings

4. Certification by Virtual Observatory

    Done for Observation Locator, pending for Visibility.

5. Implementation

 Initial pioneers have implemented one or both services:

  • The INTEGRAL gamma-ray Observatory: Visibility and Observation Locator
  • The Chandra X-ray Observatory (CXO): Visibility and Observation Locator (under development)
  • XMM-Newton: Visibility and Observation Locator
  • The GAIA mission: Visibility (displaying scanning patterns)
  • The NuSTAR mission provides their schedule in a VO-compliant format as csv files but do not provide an URL query service
  • The Insight-HXMT (Hard X-ray Modulation Telescope) has developed a visibility interface based on these protocols. Currently only accounting for Sun and Moon.
    The effects of Earth and South Atlantic Anomaly (SAA) will be included in the next version
  • Nordical Optical Telescope (NOT) - basic geometrical visibility service

As demonstration of applications, we have developed two example clients

http://integral.esa.int/toby
http://integral.esa.int/mySpaceCal/