October 18, 2017

How Many Schemes Does it Take to Light Up a Sky?

Assistant Director Swapnil Bhandari and Associate Ishita Trivedi, in this Livemint article, look at India’s night-time light satellite imagery and data to evaluate the success of electrification schemes. Excerpts below: 


"Prime Minister Narendra Modi, at the launch of the power for all scheme, Saubhagya (which promises electrification of all households), presented India’s night-time light (NTL) satellite images for 2012 and 2016 released by the US space agency Nasa recently. NTL images capture light resulting from human activity that is reflected to the outer space at night. In the absence of reliable and granular datasets, recent research indicates that NTL is a powerful tool for economists and a good proxy for urbanization, electricity consumption, and economic activity...


To understand ground realities and ascribe changes in satellite data to policy developments, it is best to validate NTL with national accounts or household survey data. One such attempt was made to track electrification in Vietnam using night-time lights by Brian Min and Kwawu Mensan Gaba. It was found that electrified villages appear brighter in satellite imagery because of public lighting, and subsequently, brightness increases with the number of streetlights. In contrast, the correlation between light output recorded by the satellite with household electricity use and access is low. Processed satellite NTL data registers a one-point increase in brightness for every 60–70 additional streetlights or 240–270 electrified homes. This implies one streetlight—as captured by NTL—is at least four times the weight of an electrified household from outer space...


Even though Ujala has been undertaken on a war-footing, the “blue blindness” of the sensor will therefore suggest that cities are getting darker when that is unlikely to be the case. This should serve as a caution to policymakers about the constraints of NTL data to reflect policy changes on the ground..."


Read the full article here

Topic : Transitions / In : OP-EDS
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