Services

Vertical Aerial Photography is taken with a special mapping camera system mounted in the bottom of the aircraft pointed straight down.  The camera system is equipped with image-motion compensation and distortion-free lenses.  The altitude of the aircraft can vary depending on the area coverage and resolution required.

Oblique Aerial Photography can be taken as either “low” or “high” obliques with a view of the ground that is not vertical.  Low obliques are a great way to highlight a close-up but not enough to include the horizon in the photo.  High obliques capture a wider view of a large area which shows the horizon line due to angle of view.

Land Surveying
Surveying can perform the necessary pre-photography mapping ground control survey by using our Trimble G.P.S. Total Station.  With the Trimble G.P.S. Total Station we can generate coordinate points within one centimeter tolerance.  The ground control survey involves planning and placement of control points with a reliable framework in reference to the surrounding terrain.  The ground control survey reconnaissance, field data collection and documentation are necessary to provide the horizontal and vertical position of the specific ground control points necessary to set up a stereo model.

Analytic Aerotriangulation
The Analytic Aerotriangulation (AT) is typically used to expand the ground control.  It reduces the number of ground control points necessary to orient a stereo model, and it ties stereo models and flight lines together as a block to create a consistent photogrammetric solution throughout the project.  This procedure enhances the use of few actual high order ground control points with additional analytic points to provide the supplemental control points necessary to set up a stereo model.

Digital Topographic Mapping
Our photogrammetric services are prepared with our Zeiss Plainicomp P3 analytic stereoplotter equipment to collect digital planimetric, digital elevation model (DEM), and digital terrain model (DTM) data.  The stereoplotter is an instrument which an operator can see a three dimensional image from two successive film diapositives overlapping each other by 60 percent to produce stereoscopic coverage in the overlap area, and it requires rigorous solutions such as camera calibration, ground control and model orientation to draw planimetric features and contours.  Our analytic steroplotter is directly interfaced with interactive graphic systems used for precise digitizing mapping, and the map data is captured directly in AutoCAD.  Each project is planned according to our client’s specification to ensure that the desired accuracies are accomplished.  After compilation the cartographic editing is performed and contours are determined from the DTM data, labels are added, necessary sheet size are determined, hard copies are either produced on vellum or double matte polyester base film, and drawing files are prepared on a CD-ROM.

Digital Orthophotography
The Digital Orthophotography is a computerized photo imagery (digital raster imagery) corrected through a digital imaging process that visually corrects distortion due to aircraft movement and variations in the elevations of the terrain. It requires photogrammetrically rigorous solutions similar to digital topographic mapping in terms of camera calibration, ground control and model orientation.  The digital terrain model (DTM) is applied to the imagery to remove the displacement effects of terrain variations so the final differential corrected image is as accurate as a conventional topographic map, and precise measurements can be made from the Digital Orthophotography.

Non-Rectified Digital Imagery
The Digital Imagery is an image that is scanned from the original aerial negative, and will be a non-rectified image which may have some distortions due to camera tilt and etc.  A non-rectified image is not accurate, does not place ground features in their true map position, and you can not make precise measurements. 

Photographic Reproduction
A Photographic Reproduction can be reproduced from the original aerial negative, digital ortophotography imagery, and non-rectified digital imagery.  We can provide aerial photo print enlargements in various sizes, add graphics to your enlargements, laminate, and mount on foam board.

Aerial Photo Archives
Western Photogrammetrics maintains a collection of current and historical aerial photography for Bakersfield, California and within Kern County California, and a collection of aerial photography for other areas.

For more information on how we can be of assistance in providing current or historical aerial photography for your project please contact our office at (661) 834-4814 or send an E-Mail.