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Glossary
A - B - C - D - E - F - I - L - M - N - O - P - R
A
Enlargement
A photograph enlargement allows to enlarge a specific zone of a photograph at a larger scale to get more details.


B
Scanning
Scan of an aerial photograph from the original film.


C
Thematic Map
Sort of map according to a specific theme, which illustrates the spread of data in a region. The map can be of a qualitative or quantitative nature.


Topographic Map
Map representing the relief of a region by showing the concret topographic observations, fixed and durable, natural or artificial, visible on the territory.


Collection
A collection is a set of photographic products and these products contain the same project characteristics: scale, emulsion, GSD, data, etc.


D
Diapositive
A diapositive is a photograph on a transparent base and met to be viewed directly or with a projector.


E
Scale
The ratio between the camera’s focal length and the plane’s altitude above the ground being photographed.


Emulsion
Photographic emulsion are made of a gelatine film with silver bromide crystals in which are the photosensitive elements. The name dates of the first years of the photography when a photosensitive emulsion was spread on a glass support before taking a photograph.


F
Map
Maps covering Quebec’s territory and showing the physiographic components and land use at a scale of 1:20,000 or 1:100,000. The represented data on these maps or maps sheet have been extracted from aerial photograph at a scale of 1:40,000.


Matching Charges
Charges are added when one of our laboratory technician has to confirm that the chosen photograph covers the same territory as another photograph.


I
Contact Print
Paper version (contact prints) of a photograph in a 23 cm X 23 cm size.


Photographs Digital Index
Flight Index at scale of 1:250,000 in a PDF format.


Flight Index
A graphical representation of all photograph’ centres, which are represented by small circles connected by straight lines (flight lines). It allows to relate the photographs to their geographical location.


Infrared
Aerial photograph acquired with a photographic emulsion hypersensitized to infrared radiance.


INPA BDPA
Databases owned by the Ministry of Natural Resources and Wildlife. One contains all aerial photograph acquisition details and the other their graphic representations.


L
Letter of Authentication
Letter confirming the ownership, the scale and the acquired date of an aerial photograph.


M
MiraPay
MiraPay is an electronic credit card paument service. It is a secure and easy to use website.


N
Negative
The negative of an image is obtained by reversing the colors of this image. It can also refer to a photographic film.


O
Orthophotograph
An orthophotograph is an aerial photograph geometrically corrected (orthorectified) such that the scale is uniform. Unlike an uncorrected aerial photograph, an orthophotograph can be used to measure true distances, because it is an accurate representation of the earth’s surface.


P
Aerial Photograph
An aerial photograph is an image taken vertically by a specialized camera, installed in an airplane equipped for this kind of work.

The aerial shots are always performed so as to have a forwardlap and sidelap between two photographs. This overlap allow the possibility to see the territory in 3D, with a special device. The optical phenomenon, which enable to see in 3D is called stereoscopy.


R
Camera Calibration Report
Report providing distorsion errors caused by the lens.


Resolution
An image resolution defines the number of pixels per lenght unit (either centimeters or inches). The resolution is referred to in DPI (dots per inch) or in PPI (pixels per inch). The higher the resolution, better the image quality will be.


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