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Technical Overview

Camera

The camera utilizes the entire focal plane of 47 square degree of the 48-inch Samuel Oschin Schmidt telescope, providing the largest instantaneous field-of-view of any camera on a telescope of aperture greater than 0.5 m: each image will cover 235 times the area of the full moon.

ZTF builds on the proven heritage of the PTF survey to provide more than an order of magnitude increase in survey speed at low risk.

An innovative optical design maintains image quality with 2.0" FWHM over the entire focal plane. Speedy modern readout electronics add only 10 seconds of overhead per exposure.

Several conference proceedings describing ZTF are available: Bellm 2014, Smith et al. 2014, Dekany et al. 2016, Bellm and Kulkarni 2017.  A formal instrument paper will be published after commissioning.

The ZTF Science Data System (ZSDS) is housed at IPAC-Caltech. This consists of the data processing pipelines, data archives, infrastructure for long term curation, and the services for data retrieval and visualization. An overview is given in Masci et al. 2018 (PASP, in review).


Status

2018 April 23

ZTF has now started science operations (2018 March 17 UT) collecting data for the MSIP, partnership, and Caltech observing programs. The robotic filter exchanger has entered Phase 3 which means nightly operations testing (it has begun to be used). The focus and guide system are in active development (these are needed to ensure a uniform image quality across the night and for exposures longer than 300s respectively). The alert infrastructure remains in commissioning with several components still under active refinement including: reliability scores from machine-learned vetting, and the Kafka-based alert distribution system. The start of the public alert stream from the public surveys is intended for late May/early June.


Data Access

At present, access is restricted to project team members (login required): 


Science Data System

An overview of the ZTF Science Data System (ZSDS) is given in:

  • Masci et al. 2018 (PASP; in review)

Pipelines, data products (including alert packets), product retrieval, formats, and usage are described in more detail in:


Technical Specifications

Telescope Samuel Oschin 48-inch Schmidt,
Palomar Observatory
Field of View

47 square degrees

Detectors 16 e2v 6k x 6k CCD231-C6
Pixel size

15 micron

Pixel scale

1.0"/pixel

Median Delivered Image Quality

2.0" FWHM

Exposure Time 30 sec
Readout Time 10 sec
Median Time Between Exposures 15 sec

Median Single Visit Depth
(5 sigma, R band )

20.4 mag (all lunar phases)
Filters ZTF g, ZTF r, ZTF i
Areal Survey Rate 3750 square degrees/hour