CRAWDAD columbia/enhants

Dataset of radiant light energy measurements.

This dataset includes radiant light energy measurements from a study by Columbia University's EnHANTs (Energy Harvesting Active Networked Tags) project.

date/time of measurement start: 2009-08-14

date/time of measurement end: 2010-11-23

collection environment: To characterize indoor energy availability , since 2009 we have been conducting a light energy measurement study in office buildings in New York City. In this study we take longtermmeasurements of irradiance (I, in units W/cm^2) in several indoor locations, and also a set of shorter-term indoor/outdoor mobile device measurements.

network configuration: For the measurements we use TAOS TSL230rd photometric sensors installed on LabJack U3 DAQ devices. These photometric sensors have a high dynamic range, allowing capturing of widely varying irradiance conditions. We verified the accuracy of the sensors with a NIST-traceable Newport 818-UV photodetector.

data collection methodology: Long-term data was collected in static locations on campus of ColumbiaUniversity. Shorter-term experiments were collected by mobile devices.

Tracesets

columbia/enhants/energy

Radiant light energy measurements collected by Columbia University's EnHANTs project.

• description: This traceset includes radiant light energy measurements collected from 2009 to 2010 in a study by Columbia University's EnHANTs project. 
• measurement purpose: Energy-efficient Wireless Network
• methodology: Since June 2009, we have been recording irradiance every 30 seconds in several different static locations using TAOS TSL230rd light-to-frequency converters installed on Lab-Jack U3 Data Acquisition boards. We also conducted several short-term experiments where measurement was conducted by sensor devices as they were moved around New York city.

There are multi-day interruptions in data due to power interruptions and device malfunctions.

columbia/enhants/energy Traces

• columbia/enhants/energy/stationary: This trace consists of long-term irradiance measurements taken at 6 static locations on the campus of Columbia University. Stationary measurements of irradiance done by Columbia University's EnHANTs project.
• file:
• SetupA_merged_2009_8_15_2010_9_13.txt.gz 
• SetupB_merged_2010_11_3_2010_11_24.txt.gz
• SetupC_merged_2009_11_7_2010_9_13.txt.gz
• SetupD_merged_2009_11_6_2010_9_28.txt.gz
• SetupE_2009_6_25.txt.gz
• SetupF_merged_2010_2_16_2010_4_15.txt.gz
• configuration: Traces A-F were made in stationary setups indoors.
• A. Students' office, South-facing, 6th floor above ground; measurement setup located on a windowsill; shading is used at all times. Trace starts on August 14, 2009 and is provided here to September 13, 2009.
• B. Students' office (same as setup A); setup on a bookshelf far from the window, receiving direct sunlight for a short portion of a day. Trace starts on November 13, 2009, and is provided here up to November 23, 2010.
• C. Departmental conference room, North-facing, with large windows and an unobstructed view; setup located on a windowsill. Shading use varies (corresponding to the needs and preferences of different affiliates using the conference room). Trace starts on November 6, 2009, and is provided here up to September 13, 2010.
• D. Students' office; corner window facing South and West; setup placed on a windowsill, shading extensively used. Trace starts on November 5, 2009, and is provided here up to September 29, 2010.
• E. Students' office directly under the office of setup A; setup on a windowsill, limited use of shading. This was a pilot measurement, done from June 25, 2009 to October 11, 2009.
• F. Students' office, East-facing; setup on a windowsill; office window often kept partially opened (the setup often receives unattenuated reflected outdoor light). Trace starts on February 16, 2010, and is provided here up to April 15, 2010.
• format: 
• * The first column is the number of seconds since the beginning of the experiment.
• * The second column is the measured irradiance. The measurements are in units of microwatts per cm^2. In records where the measured irradiance is less than 0.01, the file contains 'NaN' instead of the numeric value.
• * The subsequent columns are the timestamp of the measurement, separated into: year, month, day, hour, minute, second.

• columbia/enhants/energy/mobile: This trace contains short-term irradiance measurements collected by moving sensor devices. Mobile measurements of irradiance done by Columbia University's EnHANTs project.
• file:
• mobile-indoor-outdoor.txt.gz
• mobile-nyt-nighttime.txt.gz
• mobile-car.txt.gz
• mobile-commute.txt.gz
• configuration:
• *Indoor + Outdoor Mobile Measurements: pedestrian walking around university  campus (indoor and outdoor environments) carrying a sensor. Measurements date: April 05, 2010.
• * New York City Nighttime Measurements: pedestrian walking in New York City (Theater District and Times Square) at nighttime, with a sensor attached to a backpack. Measurements date: July 22, 2010.
• * Car-based roadtrip (sensor attached to the dashboard).
• * Commuting on public transit, sensor attached to a backpack, measurements outdoors, indoors (office, subway, train).
• format: 
• * The first column is the number of seconds since the beginning of the experiment.
• * The second column is the measured irradiance. The measurements are in units of microwatts per cm^2. In records where the measured irradiance is less than 0.01, the file contains 'NaN' instead of the numeric value.
• * The subsequent columns are the timestamp of the measurement, separated into: year, month, day, hour, minute, second.