Developing a TMT-IRIS Astrometry Error Budget Software Tool

This mini-project was completed in 2019 as part of the TMT Early-Career Initiative (TECI) program.

Project Team

Sireesha Chamarthi (Indian Institute of Astrophysics)

Trupti Ranka (Giant Magellan Telescope)

Arun Surya (University of California, San Diego)


Project Consultants

Jessica Lu (University of California, Berkeley – TMT IRIS Science Team)

Matthias Schoeck (TMT International Observatory) 

Project summary

The project team developed a web-based software tool to calculate the TMT astrometry error budget for different science cases. The astrometric error is calculated from the variance of star positions, taking into account various factors such as observational field parameters or opto-mechanical errors in the telescope, along with the detector and instrumental errors. The main focus of the project was to build a software front end to the error budget analysis from earlier work led by Matthias Schoeck (TIO).  A web based tool was developed in Python and Dash framework (plotly) and successfully deployed. The tool allows users to input parameters of a science case and calculate the associated astrometric error. There is also an analysis tab that gives changes in the error budget with different source magnitudes. 

In September 2019 the team traveled to UC Berkeley for a one-week visit with Jessica Lu and Matthias Schoeck, during which they refined the astrometry calculator and updated the web based tool.

Project members have submitted an abstract to the 2020 SPIE conference, titled “Astrometric error analysis for ELTs: Analysis, methodology and software tools.”

Project deliverables and documentation

Online IRIS astrometry error budget tool

Github repository for error budget tool

Further documentation on the project is available in the github repository.