The DSA-110

The NSF-funded Deep Synoptic Array-110 (DSA-110) is a radio interferometer purpose-built for fast radio burst (FRB) detection and direct localization. The array is sited at the Owens Valley Radio Observatory (OVRO). 110 × 4.65-m dishes will continuously survey for FRBs at frequencies between 1280 – 1530 MHz. Over a three-year science program, the DSA-110 will deliver a sample of more than 300 FRBs localized to regions smaller than 3 arcseconds (<1/1000 of a degree) on the sky. This is made possible by a suite of novel instrumentation developed by our group, including precisely engineered antennas, ultra-low noise ambient-temperature receivers, and a powerful real-time, autonomous data-analysis system. Public FRB alerts will be issued via the VOEvent service to the entire astronomical community to ensure rapid follow-up of DSA-localized FRBs.

Image: G. Hallinan

Specifications

(Image: V. Ravi)

    
            Parameter
            Value
        
            Number of dishes *
            110
        
            Dish diameter
            4.65 m
        
            Aperture efficiency
            0.65
        
            System temperature #
            25 K
        
            Frequency band
            1280 – 1530 MHz
        
            Number of channels
            8192
        
            FRB search sensitivity (7 .5σ, 1 ms) †
            < 1.7 Jy ms
        
            Field of view
            10 deg2
        
            Maximum baseline
            2.6 km
        
            FRB localization accuracy
            ± 1.5 arcsec
        
            Survey speed
            3.1 × 104 deg2 m4 K−2
        
            * 95 dishes are in a Tee-shaped core for FRB searching, with 15 outriggers. 

            # Measured on-sky, including all contributions.

            † This applies within the entire field of view.

Parameter	Value
Number of dishes ^*	110
Dish diameter	4.65 m
Aperture efficiency	0.65
System temperature ^#	25 K
Frequency band	1280 – 1530 MHz
Number of channels	8192
FRB search sensitivity (7 .5σ, 1 ms) ^†	< 1.7 Jy ms
Field of view	10 deg²
Maximum baseline	2.6 km
FRB localization accuracy	± 1.5 arcsec
Survey speed	3.1 × 10⁴ deg² m⁴ K⁻²
* 95 dishes are in a Tee-shaped core for FRB searching, with 15 outriggers. ^# Measured on-sky, including all contributions. ^† This applies within the entire field of view.

Technology

The DSA-110 is made possible by novel technologies developed by the instrument team, together with the adaptation of open-source and off-the-shelf hardware and software components.

OVRO designed and built mount and drive, remotely steerable in elevation.
(Image: M. Hodges)

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Ambient-temperature low noise amplifier (LNA) designed and built by the OVRO receiver lab, led by Sandy Weinreb, for the DSA-110, delivering 7K noise temperature. The receiver lab also designed and built custom RF-over-fiber signal transport modules, and signal-conditioning components.
(Image: S. Weinreb)

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Real-time, autonomous digital backend that performs full cross-correlation, self-calibration, beamforming of the core antennas, FRB searching, and voltage recording. All components of the DSA-110 are monitored and controlled using a custom etcd-based architecture.

Location and Configuration

The DSA-110 is currently under construction at OVRO, and a 63-antenna deployment is being commissioned. The array will consist of a core of 95 antennas arranged on an existing Tee-shaped infrastructure for FRB searching, and a further 15 outrigger antennas distributed across the OVRO site for FRB localization. All antennas are served with power and optic-fiber infrastructure, the latter for signal transport and monitor/control. A real-time search pipeline will trigger the storage of data from all antennas for the purposes of offline localization. 66 antennas are currently operational, including all outriggers and 51 core antennas.