Accounting of Transportation Networks


More frequent image captures make it possible to monitor the progress of infrastructure projects. High resolution imagery and video can help to measure road traffic and quality. Satellite imagery and analysis techniques can provide the underlying data to inform infrastructure investments.

In countries lacking infrastructure maps, imagery can offer a relatively cheap base layer from which to map the national road network. The images below explore the suitability of imagery at various resolutions for identifying road features, which exemplifies the necessary compromise between detail and acquisition cost. The highest-resolution commercial imagery today (0.3 meters per pixel) allows for the detection of narrow, unpaved footpaths. These become invisible at 1.5 meters, at which the gridded residential roads are the smallest observable feature. This grid remains recognizable at 2.5 meters, but is more likely to confuse with the surrounding vegetation. At 5-meter resolution, even the relatively large secondary road which cuts through the neighborhood becomes difficult to distinguish reliably, making the single primary road that travels the length of Palawan the only visible linear feature.