Node {{{s3-lg1}}} is the third sector of [https://wiki.cosmos-lab.org/wiki/Hardware/Nodes#LargeNode Large Node] 1, located on the 18th floor roof of the Mudd Building at Columbia University, roughly 68m above the campus level and 78m above the street level. Unlike sectors 1 and 2, sector 3's [https://wiki.cosmos-lab.org/wiki/Hardware/antennas#Directionallargenodesector antenna] is pointed to the west overlooking the Columbia Morningside Heights campus. 

'''''Contributors''': Gulnur Avci, Sienna Brent, Angel Daniel Estigarribia, Leoni Lu, Watson Mushimbei, Dwiref Oza, Doris Qian, Irfan Tamim, Jeswanth Yadagani''

'''''Data''': [https://wiki.cosmos-lab.org/raw-attachment/wiki/Architecture/Deployment/Measurements/s3-lg1/rssi_coverage_map_s3-lg1.csv Available here (CSV)]''

==== Node photographs
 ||||||Figure 1: Photographs of s3-lg1 ||
 || [[Image(s3-lg1_campus.jpg, 350px)]] || [[Image(s3-lg1_roof.jpg, 197px)]] || 
 || (a) Looking up from campus level  || (b) From Mudd building rooftop ||

==== Coverage
[https://wiki.cosmos-lab.org/wiki/Architecture/Deployment/Measurements Coverage measurements] were performed around the campus area in August 2020. Subsequent measurements were performed between May and December 2021 to both corroborate the measurements from August 2020 as well as extend the measurement area. In total, 506 measurements were taken in a three to five meter-spaced grid in the campus, Broadway, and 120th St. areas. The measurement results are presented below.

 |||||| Figure 2: Coverage measurement results for {{{s3-lg1}}}. ||
 || [[Image(rssi_coverage_map_s3-lg1.png, height=400px)]] || [[Image(columbia_campus_antenna_coverage.png, height=400px)]] ||
 || (a) Measurement results || (b) 60 degree 3dB antenna beamwidth displayed over campus map ||

These measurements demonstrate an RSSI of around -85 dBm at a 300m straight-line distance, even in the presence of multiple buildings blocking line of sight. As would be expected, the locations close to the node and within the 3dB beamwidth experience higher RSSI. 

Of particular note are the measurements in the eastern area of the campus. This area is not only shadowed by several buildings, but is also outside of the beamwidth of {{{s3-lg1}}}'s antenna. This demonstrates that {{{s3-lg1}}} provides coverage for a significant area of the Columbia campus, making it useful for experiments undertaken in this area.