Air Surveys & Orthophotos

Since being founded in 1923 Hansa Luftbild has chiefly been renowned as an aerial survey company whose aircraft and aerial cameras has enabled it to undertake aerial survey work both nationally and internationally for survey authorities, relevant public bodies, and private clients.

To this day Hansa Luftbild has several aircraft, as well as digital large format cameras and laser scanners. In recent years, however, the range of available sensing devices has much expanded. Further devices such as thermal cameras, and hyperspectral imaging systems etc can also be put at the client’s disposal.

Nothing is better for an overview than the view from above. Aerial images show the area under investigation in true form and thanks to automated modern rectification and correlation processes, as well as high image resolution, the smallest details are accurately positioned: the basis for every GIS, for digital surface models, for every cadastre, for every query.

Aerial imagery and orthophotos can be used to document and analyse vegetation in specific areas. So correlations (eg between retarded growth and waterlogging) and delimited areas (eg inaccessible areas) can be captured more accurately and with greater detail, than possible by ground based survey methods.

Aircraft, helicopters and drones are indispensable as transport media for aerial survey sensors.

An important follow-on product of the iDSM is the so-called true orthophotos. Due to radial displacement it is impossible to avoid distortion of above ground objects using conventional orthophotos. Only true orthophotos allow objects on the earth’s surface to be represented with orthogonal and positional accuracy.

Since for the entire image height information is available, all image pixels can also be accurately rectified. Formerly hidden sections in the imagery (eg areas behind houses) can be filled in using information from adjacent images. For this reason aerial surveys for true orthophotos must be carried out with a high overlap (eg 80 % forward overlap / 60 % lateral overlap). A true orthophoto is an orthophoto with removed occlusions and no invisible spots.