with the broader community so they can be used to fill gaps or validate other observations with CCD instruments.
A radio astronomer is writing a proposal for observing time. They use SatHub to estimate how many hours they need (and at what time of year, etc.) to successfully image their targets and minimize interference from satellites at their observing frequencies.
A data scientist is interested in testing a new image feature detection algorithm. They use SatHub to access images from several astronomy databases in order to train and test their algorithm on streaks, point sources, extended sources, and artifacts.
In this Observations Working Group Report, we focus on implementing the Astronomical Data Repositories (Section 1.2), Training Curriculum (Section 2), and Orbital Solution Portal (Section 3) portions of SatHub. The Software Tools portion is largely addressed by the Algorithms Working Group Report, and we note that a significant number of tools already exist or are in development and should be at minimum linked to from SatHub (e.g., ARCADE[1]). We anticipate the establishment of an IAU Centre will enable many aspects of SatHub’s real-time collaboration needs.
1.2. Collecting satellite observations
As populations of LEOsats increase, observers of the night sky worldwide will more frequently encounter them. For optical telescopes with CCD imagers — and astrophotography more generally — they appear as bright streaks in images. The signatures of LEOsats in different kinds of telescopes (e.g., radio) and instruments (e.g., spectroscopy) manifest differently. The impacts of observable LEOsats on science and the human experience of the night sky can vary widely. Effectively implementing SATCON1 Recommendation 8 requires observers to share data affected by LEOsats in an accessible way.
1.2.1. Trailblazer
Trailblazer is an open data repository of astronomical images containing satellite trails[2]. Meredith Rawls (U Washington/Rubin Observatory) is leading development of this service with Dino Bektesevic (U Washington). It will be a living, queryable archive that welcomes uploads from anyone with recent FITS images with a valid World Coordinate System (WCS) affected by satellites. Trailblazer is being built publicly with open source tools, and will allow observational astronomers to salvage some scientific value from their satellite-streaked images, and it will give ready access to a user-friendly dataset to any group seeking to quantify scientific impacts of satellite trails.
A sustained funding source will be necessary to maintain and improve Trailblazer long-term. Nevertheless, a website with minimal functionality should exist by the end of 2021. The project is being developed in Django and utilizes Amazon Web Services. The main functionalities are file upload, thumbnail gallery display, and a query interface with a download option. When a new image is uploaded, a metadata database is populated containing critical information (exposure time, exposure duration,
