Sunday, October 26, 2008

Harry's World Atlas (October 25, 2008)

Harry's World Atlas is an atlas based on images of the Earth in the Google Earth database. As an observationally based atlas, it is less dependent on official sources than previous atlases.

At the current time, nine ISO 3166 country codes are covered:

Afghanistan (AF)
China (CN)
North Korea (KP)
Pakistan (PK)
South Korea (KR)
Tajikistan (TJ)
Turkmenistan (TM)
Uzbekistan (UZ)
Kyrgyzstan (KG)
Russia (RU) partial

Harry's World Atlas is produced in three phases: observation, identification, and population analysis.

In the observation phase, Google Earth is scanned from west to east in strips with a width of several kilometers. Urban areas with an area of larger than 1 square kilometer are identified and their areas are estimated by counting grid squares.

In the identification phase, the urban areas are identified by referring to print and Internet sources. The urban areas are also placed in the administrative hierarchy of the country under observation. In some cases, the urban areas cannot be identifed and names are assigned which refer to the urban area by its position with respect to known urban areas.

In the population analysis phase, the population of the urban areas is inferred from census data, if available. In many cases, populations must be inferred from their measured areas and estimates of population density.

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