Publications and Projects

Time-of-Flight Soil Moisture Estimation Using RF Backscatter Tags

Our short paper titled Time-of-Flight Soil Moisture Estimation Using RF Backscatter Tags has been accepted to IGARSS 2020, the IEEE International Geoscience and Remote Sensing Symposium.

Soil Moisture Sensing Demo

I’ll be presenting a live demo of our soil moisture sensing work at IPSN ‘20 in Sydney, Australia during April 21-24. Here’s a video for those who can’t make it to Australia:

RF Soil Moisture Sensing via Radar Backscatter Tags

Our paper, “RF Soil Moisture Sensing via Radar Backscatter Tags” is under review and a pre-preint is available on the arXiv.

Wireless Soil Moisture Sensing Won Best Poster Award at SenSys '19 N2Women Workshop

Our poster, “Wireless Soil Moisture Sensing”, won an award for best poster at the SenSys ‘19 N2Women Workshop.

2019: BackCam, Wireless Computer Vision Using Commodity Radios (IPSN)

Our paper has been accepted for publication at IPSN ‘19 (Information Processing in Sensor Networks): BackCam, Wireless Computer Vision Using Commodity Devices by Colleen Josephson, Lei Yang, Pengyu Zhang and Sachin Katti.

2018: Using RF backscatter to sense soil moisture

Backscatter tag
In Summer 2018 I was a research intern at Microsoft Research in Redmond, WA. My mentor was Ranveer Chandra and I worked on next-generation soil sensing in the Farmbeats project. We all got to demo out work to Bill Gates himself, and in October it was featured on his blog. There was even a video made where I made a few brief appearances showcasing our backscatter tag and digging holes for experiments.

2017: Freerider, Backscatter Communication Using Commodity Radios (CoNEXT)

At the CoNEXT 2017 conference in Seoul, South Korea, we introduced the design and implementation of FreeRider, the first system to enable backscatter communication with multiple commodity radios, such as 802.11g/n WiFi, ZigBee, and Bluetooth, while these radios are simultaneously used for productive data communication. Furthermore, we are, to our knowledge, the first to implement and evaluate a multi-tag system.

2016: Field Recordings from Around the Globe

In 2016 I circumnavigated the globe, visiting friends and family across five continents. I used a digital recorder to make field recordings of the various interesting things I heard during my travels. This is a playlist of the highlights.

2014: Network Coded Anonymous Gossip (MEng Thesis)

MIT’s EECS department has a Masters of Engineering (MEng) program where qualifying undergraduates can apply to stay for an additional year and complete a master’s degree. The program requires both coursework and a research thesis. My research advisor was Professor Muriel Medard, and my topic was on using network coding for anonymous network communications.

2013: WiFi bitrate selection algorithm verification term paper

This was my term project for 6.829, MIT’s graduate computer networking class. We compared the performance of two wireless bit-rate selection algorithms and made improvements to one of them. Bit-rate selection is the process of choosing which bit rate to send with over the wireless link. Unlike wired networks, it is very common for wireless networks to send at lower rate that the maximum the channel supports. This is because wireless channel conditions are rarely ideal due to factors such as fading and interference. The goal is to select a bit rate that achieves the highest throughput, and to keep that rate updated as channel conditions change.