Annual Progress Report for 2015NASA Award Number NNX15AT65G

MULTI-SOURCE IMAGING OF INFRASTRUCTURE AND URBAN GROWTH USING LANDSAT, SENTINEL AND SRTM

Christopher Small (PI)

Lamont-Doherty Earth ObservatoryColumbia University

Palisades, NY 10964 USA

Summary of Accomplishments:

Developed scene selection criteria for Landsat multi-season spectral stability composite procedure.

Produced multi-season stable reflectance composites for Beijing, Cairo, Dhaka, Denver, Naples, New Delhi, New York, São Paulo, Shanghai, Tokyo

Began multi-landscape analysis of SRTM backscatter with spectral composition and variability for Beijing, Dhaka, New York & São Paulo.

Began comparative analysis of Landsat 8 and Sentinel-2 imagery for shadow aggregation effects.

Presented preliminary results at NASA+EARSeL LCLUC meeting and Landsat-Sentinel Science Team meeting in 4/5 2016.

Our work in year 1 of the grant focused on seven objectives:

1) Acquisition, processing and multi-season compositing of Landsat imagery for first 10 test cities.

2) Development of scene selection criteria (illumination, phenology, soil moisture) to determine minimum number and optimal timing of Landsat scenes necessary to capture land cover seasonal variabilty.

3) Implementation of multi-season composite procedure to produce spectral stability maps for the first 10 test sites.

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4) Acquisition of SRTM radar backscatter imagery from JPL for subset of test cities.

5) Exploratory analysis and characterization of the optical/microwave spectral response spaces for different land cover types.

6) Acquisition and comparative analysis of Sentinel-2 optical imagery (where available) with Landsat 8 imagery. Focus on spectral mixing spaces and effect of spatial resolution on spectral clustering.

7) Presentation of results at NASA-EARSeL LCLUC meeting in Prague 5/2016.

All objectives were achieved.The most significant of these achievements is the development of the stable land cover fraction map because it was the greatest source of uncertainty as to the success of the algorithm to be used for development of the infrastructure index.

Currently, research is focused on development of a general relationship between radar backscatter, building volume and building shadow for different density settlements. This is being accomplished by parallel comparative analyses along urban-rural gradients in 4 different environments. Examples are given below, with comparison to night lights.

Our Plan for the Coming Year

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Summer 2016 – Conduct comparative analyses of SRTM+Sentinel-1 radar backscatter with the 0.3 m LiDAR DSM for New York City to derive quantitative relations between building height variability, optical shadow density and backscatter response. This analysis will also include comparisons with QuikScat-derived building volume estimates derived by Son Nghiem’s team at JPL. Prepare manuscript on urban vertical structure and growth.

Fall/Winter 2016 – Conduct comparative analyses of SRTM & Sentinel-1 radar responses in areas believed unchanged 2000-2015. Apply consistencies observed in pseudo-invariant targets to other cities in test group.

Spring 2017 – Begin integration of Sentinel-1 radar with Landsat+Sentinel-2 merged EM fractions.

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