High-resolution aerial photographs to be used as evidence in disputes concerning illegal structures and land and property ownership as well as for academic research can now be printed in the comfort of home, eliminating the inconvenience of having to visit City Hall in person to obtain such images.
The Seoul Metropolitan Government has developed the “Aerial Image Viewer” in order to offer an Internet-based aerial image printing service through the Seoul Aerial Image Service website (http://aerogis.seoul.go.kr), where individuals can download and print aerial images in their own homes.
In 2012, the Seoul Metropolitan Government made available online the Big Data of about 100,000 aerial images that have been taken of the entire city every year for the last 43 years since 1972, providing citizens access to exceptionally high-resolution (25cm) images that far surpass aerial images of the city provided by other organizations or Internet portal sites. On an image with a resolution of 25cm, an object with a diameter of 25cm appears as a dot.
These online aerial images were accessed about 1.2 million times between 2012 and 2014, while a total of 6,986 aerial photographs were provided to citizens who visited City Hall to receive images in person. Compared to Internet portal sites, which usually update the images of only major areas, Seoul’s aerial image service is particularly useful as the government provides aerial images of the entire city of Seoul by year for more diverse and practical uses.
Seoul Aerial Image Service for Citizens (http://aerogis.seoul.go.kr) – After the completion of construction
After the completion of construction
Aerial photograph taken in 2014 (Near Yeomri Elementary School, Seoul)
Registration is not necessary for printing, but the service is accessible only after the user’s identity has been verified using an I-PIN (Internet Personal Identification Number). There is a fee of about KRW 10,000 to 20,000 per aerial image.
In order to prevent the illegal distribution or printing of downloaded aerial images, the images are watermarked and protected by DRM (Digital Rights Management), a technology built into the images to prevent any counterfeiting or alteration. Also, a test print function is available to prevent printing errors.
Area surrounding Seoul City Hall
Besides simple aerial images, the Seoul Aerial Image Service also provides orthoimages, which can help create added value in web development, as well as a thematic time series service that provides citizens with a look at the changes in high-interest areas in Seoul.
Orthoimages are provided in an open source API format, free of charge, to anyone who files a request. These orthoimages, taken in 2013, can be used to create a variety of content.
The thematic time series service presents photographs of selected areas in Seoul, including parks, stadiums, and the Hangang River, that show changes in the areas over the course of time. Citizens may suggest additional areas and regions if they wish, and even share them with friends and followers on SNS channels, such as Twitter and Facebook.
∗ Seoul Aerial Image Service – http://aerogis.seoul.go.kr