How do photogrammetrists contribute to GIS?

Photogrammetrists play a crucial role in GIS by measuring features and distances from photographs, particularly aerial images. This process is known as photogrammetry, where data extracted from photographs can be used to create accurate maps and three-dimensional models of the Earth's surface. By utilizing this technique, photogrammetrists can derive precise geographical information, such as elevation, distances, and spatial relationships between various features. This information is critical for various applications in GIS, including urban planning, environmental monitoring, and resource management, as it provides a foundational layer of spatial data that enhances analysis and decision-making.

The other choices relate to different aspects of GIS but do not specifically capture the unique contribution of photogrammetrists. For example, using CAD programs for mapping relates more to designing and drafting rather than the measurement technique associated with photogrammetry. Creating databases pertains to data management, while conducting field surveys involves direct data collection from the ground, which is distinct from the airborne perspective that photogrammetrists provide through imagery analysis.