Performance of medium format digital aerial sensor systems (original) (raw)

Ten Years Large Format Digital Aerial Cameras, a Review

Large format Digital aerial cameras were introduced 10 years ago in Amsterdam at the ISPRS Conference in July 2000. Only about 5 years later the digital large format aerial cameras had overtaken the majority of photogrammetric image production. The new technology did change the photogrammetric workflow, replaced well known components and made the end-to-end all digital production chain available to the photogrammetric community. Helpful if not essential was the development of computers, storage media, software products and other IT components which are the basis of any digital processing scenario. The development of large format digital aerial camera shows a specific evolution. Frame size, multi spectral capability, on board storage capacity and other details of such sensor systems are discussed within this contribution. The impact on the productivity of photogrammetric production units, the number of frames taken by one sensor during one year and the increasing appetite for geo data are as well topics of this article. Furthermore we discuss the development of photogrammetric software solutions and their ability to handle large volumes of pixel data. The need for automation and the introduction of new photogrammetric products are in focus. As a contribution to further discussions we try to give an outlook for the next few years and to ask ourselves the question if the photogrammetric community is well prepared for the next decade.

Digital Airborne Cameras-Status and Future

Proceedings of ISPRS Hannover Workshop, 2005

The traditional way of airborne photogrammetric imaging is undergoing major changes currently. With the advent and operational availability of digital (large-format) imaging sensors a strong and powerful alternative to the standard way of analogue imaging appeared. The ...

Airborne high-resolution digital imaging system

Journal of Applied Research and Technology

A low-cost airborne digital imaging system capable to perform aerial surveys with small-format cameras is introduced. The equipment is intended to obtain high-resolution multispectral digital photographs constituting so a viable alternative to conventional aerial photography and satellite imagery. Monitoring software handles all the procedures involved in image acquisition, including flight planning, real-time graphics for aircraft position updating in a mobile map, and supervises the main variables engaged in the imaging process. This software also creates files with the geographical position of the central point of every image, and the flight path followed by the aircraft during the entire survey. The cameras are mounted on a three-axis stabilized platform. A set of inertial sensors determines platform´s deviations independently from the aircraft and an automatic control system keeps the cameras at a continuous nadir pointing and heading, with a precision better than ± 1 arc-degre...

Results of a Performance Test of a Dual Mid-Format Digital Camera System

The low weight and the relatively low cost of medium format digital cameras have pushed the use of those units for aerial survey. These medium format cameras are often used as secondary sensors together with other aerial sensors like LiDAR systems. The rising number of pixels per camera leads to an increasing interest in medium format systems as main sensors, especially for smaller survey aircraft. While the number of pixels across flight direction is not critical for capturing linear objects, like power lines or pipelines, the relatively small number of pixels compared to large format systems increases the necessary flying effort for photogrammetric blocks. In case larger blocks have to be flown efficiently, it is possible to combine two or more of such medium format cameras (dual-or multi-head solutions). This combination of medium format cameras increases the possible image strip widths and therefore reduces the flying time and distance for block projects. A performance test of a...

The Z/I Imaging Digital Aerial Camera System

1999

With the availability of a digital camera, it is possible to completely close the digital chain from image recording to plotting. The key decision regarding the camera design in this case is whether a CCD sensor should be used on a line or a matrix basis. In view of the high geometric accuracy requirements in photogrammetry, Z/I-Imaging focused its development on a digital camera based on a matrix sensor. An essential aspect of this decision was not only the aerial camera system, but the entire photogrammetric process to the finished photo or mapping product was also taken into account. The approach chosen will also maintain the usual central perspective for the new digital images.

Medium Format Digital Cameras-A Eurosdr Project

2008

More medium format airborne camera systems are in operation globally than the well recognised large format digital imaging systems. EuroSDR has initiated a digital medium format project to investigate the market, the geometric and radiometric potentials as well as current trends and future developments. After a categorisation of small and medium format systems an in depth comparison to large format cameras is given. Beside the apparent differences in size and system cost, the special problems such as differences in the interior orientation, the minimum GSD and the photogrammetric workflow are addressed. Medium format cameras require geometric and radiometric calibration. Medium format cameras have established their own markets and application domains, such as strip mapping and the joint operation with a laser scanner. A market overview compares five different camera systems. A description of current trends and future developments concludes the paper.

Digital photogrammetric cameras: possibilities and problems

1999

Airborne digital sensors are about to widen the choices in photogrammetry. The transition from analytical to digital photogrammetry is well advanced and the dividing lines between photogrammetry and remote sensing grow increasingly blurred. One of the advantages of direct digital data capture in the air is the possibility of capturing multispectral data as well as panchromatic. Positioned between modern film-based aerial mapping cameras with their extremely high resolution and, at the other end of the spectrum, the forthcoming high-resolution satellite sensors, the new airborne devices can access a large market. Two technologies are available as the basis for airborne digital sensors - linear and area array CCDs. The performance of the latter is insufficient to offer swath widths and resolutions comparable to film cameras. The most promising alternative appears to be linear arrays, arranged in a triplet on the focal plane, one forward-, one nadir- and one backward-looking. When comb...

Is there an ideal digital aerial camera

2006

The IGN digital camera project was set up in the early 90's and the first research surveys were carried out in 1996. The digital camera was first used in production in 2000 when the DMC and ADS40 systems appeared on the market at the beginning of the 21 st century. Since then, two medium format systems (Applanix DSS322 and DiMAC system) and a third large-format system (Vexcel UltraCamD) appeared on the surveying market. Today, IGN's system could appear very underperforming in terms of possible swaths and frame rates compared with the ones offered by large format cameras ; and parts of our electronics have become obsolete. This is the reason why we recently reanalyzed the needs of IGN in term of digital imagery and confronted them to the main characteristics and capabilities of the different existing commercial systems. Considering that Bayer acquisition without a coupled panchromatic acquisition does not allow an image reconstruction of good quality and considering that an acquisition system based on CCD area sensors must be equipped with a Forward Motion Compensation (FMC) able to compensate dozens of pixels, we only focused on the three large-format systems that are : Intergraph's DMC, Vexcel's UltracamD, and Leica Geosystems' ADS40. Each of these three systems has its pros and cons and no one seems to bring an answer to all our needs.

Digitalne aerokamere velikog formata

The paper presents current situation of technologies in the field of airborne digital large format cameras. Design of different cameras is detailed described with their specificities.