# So you think you can DAS? A viewpoint on delay-and-sum beamforming

arXiv: https://arxiv.org/abs/2007.11960 · HTML: https://mlsanity.com/paper/2007.11960/

## Key facts

- Cited by 14 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 23 Jul 2020.

## Built on by (most cited first, 14 of 14)

- [Speckle2Self: Self-Supervised Ultrasound Speckle Reduction Without Clean Data](https://mlsanity.com/paper/2507.06828/) (2025)
- [Digital twins enable full-reference quality assessment of photoacoustic image reconstructions](https://mlsanity.com/paper/2505.24514/) (2025)
- [Invisible-to-Visible: Privacy-Aware Human Segmentation using Airborne Ultrasound via Collaborative Learning Probabilistic U-Net](https://mlsanity.com/paper/2205.05293/) (2022)
- [Optimization of array encoding for ultrasound imaging](https://mlsanity.com/paper/2403.00289/) (2024)
- [Ultrasound Image Enhancement with the Variance of Diffusion Models](https://mlsanity.com/paper/2409.11380/) (2024)
- [Deep Learning Strain Estimation: Is Physics-Based Simulation the Solution?](https://mlsanity.com/paper/2605.28697/) (2026)
- [Patch Based Transformation for Minimum Variance Beamformer Image Approximation Using Delay and Sum Pipeline](https://mlsanity.com/paper/2110.10220/) (2021)
- [Invisible-to-Visible: Privacy-Aware Human Instance Segmentation using Airborne Ultrasound via Collaborative Learning Variational Autoencoder](https://mlsanity.com/paper/2204.07280/) (2022)
- [Compact Implicit Neural Representations for Plane Wave Images](https://mlsanity.com/paper/2409.11370/) (2024)
- [Image-Based Metrics in Ultrasound for Estimation of Global Speed-of-Sound](https://mlsanity.com/paper/2503.14094/) (2025)
- [Uncertainty Estimation for Trust Attribution to Speed-of-Sound Reconstruction with Variational Networks](https://mlsanity.com/paper/2504.11307/) (2025)
- [Acoustic Imaging for UAV Detection: Dense Beamformed Energy Maps and U-Net SELD](https://mlsanity.com/paper/2508.00307/) (2025)
- [Ultrasound Tomography of Musculoskeletal Tissues with Generative Neural Physics](https://mlsanity.com/paper/2508.12226/) (2025)
- [Null-Space Diffusion Restoration with Adaptive Uncertainty-Guided Fusion for Ultrasound Speckle Reduction](https://mlsanity.com/paper/2608.29820/) (2026)

## Abstract (arXiv)

Delay-and-sum (DAS) is the most widespread digital beamformer in high-frame-rate ultrasound imaging. Its implementation is simple and compatible with real-time applications. In this viewpoint article, we describe the fundamentals of DAS beamforming. The underlying theory and numerical approach are detailed so that users can be aware of its functioning and limitations. In particular, we discuss the importance of the f-number and speed of sound on image quality, and propose one solution to set their values from a physical viewpoint. We suggest determining the f-number from the directivity of the transducer elements and the speed of sound from the phase dispersion of the delayed signals. Simplified Matlab codes are provided for the sake of clarity and openness. The effect of the f-number and speed of sound on the lateral resolution and contrast-to-noise ratio was investigated in vitro and in vivo. If not properly preset, these two factors had a substantial negative impact on standard metrics of image quality (namely CNR and FWHM). When beamforming with DAS in vitro or in vivo, it is recommended to optimize these parameters in order to use it wisely and prevent image degradation.