![Page 1: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/1.jpg)
Life Under Your Feet
![Page 2: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/2.jpg)
![Page 3: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/3.jpg)
![Page 4: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/4.jpg)
Sensor Network Design Philosophies
• Use low cost components
• No access to line power– Deployed in remote locations
• Radio is the biggest consumer of power– Minimize radio communication
• Transfer data in bulk (amortize radio costs)– Data Latency vs. Lifetime tradeoff
![Page 5: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/5.jpg)
![Page 6: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/6.jpg)
Deployments
![Page 7: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/7.jpg)
All Data Online!
![Page 8: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/8.jpg)
Cub hill locations (50)
![Page 9: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/9.jpg)
Soil Temperature Dataset
![Page 10: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/10.jpg)
Data Features
– Correlated in time and space
– Evolving over time (seasons)
– Gappy (Due to hardware failures)
– Faulty (Noise, Jumps in values)
![Page 11: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/11.jpg)
Goals
Leverage spatiotemporal correlations:
• Model-based fault detection• Increase network lifetime
– Tradeoff latency for reduced communication
![Page 12: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/12.jpg)
Examples of Faults
![Page 13: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/13.jpg)
Motivation
• Environmental Scientists want fault-free data and want to see visualizations
• They start looking at the actual data much later– Opportunity to postpone collecting all data
• ~ 5% of data is faulty
![Page 14: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/14.jpg)
Basic Observations
• Hardware failures causes entire “days” of data to be missing– Temporal correlation alone is not enough
• If we look in the spatial domain,– For a given time, at least > 50% of the
sensors are active
![Page 15: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/15.jpg)
Initialization
Good Period
![Page 16: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/16.jpg)
Tamas’ Iterative and Robust gap-filling (MATLAB)
![Page 17: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/17.jpg)
Sketch
• Estimate fixed common effect (daily median)
• Subtract location-specific deviation from common effect
• Model residuals using PCA– Basis defined in the spatial domain– Initialized using good data– Vectors are randomized and fed one by one– Gaps corrected using L2 minimization– Use reprojection error to remove outliers
![Page 18: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/18.jpg)
Smooth / Original
![Page 19: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/19.jpg)
Original and Ratio
![Page 20: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/20.jpg)
Moving forward
• Better way to model these correlations?
• How do we pick a subset of locations that are informative:
– 2 phase operation– Periodically download from everyone– In between, use correlations to produce maps and
movies– Extend network lifetime
![Page 21: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/21.jpg)
Soil Moisture and Ratio
![Page 22: Life Under Your Feet. Sensor Network Design Philosophies Use low cost components No access to line power –Deployed in remote locations Radio is the](https://reader031.vdocument.in/reader031/viewer/2022032205/56649e8e5503460f94b9181b/html5/thumbnails/22.jpg)
Moisture vs Ratio (zoom in)