Aug 19, 2002 – ISTAR Americas has delivered a fully processed natural-color TrueOrtho image of the City of Baltimore to the Mayor’s Office of Information Technology in 10 weeks. ISTAR acquired one-foot-resolution, digital aerial data for the entire city in March and delivered a seamless, finished Citywide TrueOrtho image mosaic by early June.
The ISTAR Americas’ TrueOrtho imagery will complement base map data provided by Baltimore’s Enterprise Geographic Information Services group to over a dozen city departments and agencies. With city employees regularly accessing geographic information through the city’s intranet, Baltimore is actively pursuing the application of geographic information and technology to address city issues.
The TrueOrtho imagery is also being used by Mayor Martin O’Malley’s CitiStat program that has developed a national reputation for tracking city government performance and improving municipal accountability (see https://www.baltimorecity.gov/news/citistat/index.html for additional information on CitiStat and the use of geographic information in Baltimore.)
The City of Baltimore is one of many mapping projects where ISTAR Americas has used the HRSC-AX airborne camera developed by DLR, the German Space Agency. This digital camera acquires imagery with less than one-foot pixel resolution from an altitude of 20,000 feet, allowing it to cover huge tracts of land in a single swath. In addition, the new camera operates in the near-infrared and visible portions of the spectrum, generating 24-bit false and natural-color imagery.
TrueOrtho image mosaics are ISTAR Americas’ signature dataset, although the company also produces one-meter resolution 3D surface models. TrueOrtho data are orthorectified from multiple swaths of digital HRSC-AX image data, and processed pixel-by-pixel in an automated system to ensure each point is represented in its exact horizontal and vertical position on Earth. The result is a TrueOrtho image in which all surface features are visible – even alleys, streets and the sidewalks between tall buildings – and a realistic 3D model that’s an exact match to the image data.