What does the term "Aerial photography scale" mean ?

The aerial photography scale indicates the approximate relation between the size of an object as it appears on an image and its real size on the ground. For example in a 1:5.000 aerial photograph, a distance of 1mm on the photograph stands for a 5.000mm or 5m distance on the ground. The aerial photography scale is always approximate, because it varies within a single photograph with the ground elevation.

What does the term " 2X, 4X, 5X Enlargement" mean ?

It means 2 times (2X), 4 times (4X) or 5 times (5X) enlargement of a photograph.

What is the size (format) of an original aerial photograph for surveying purposes ?

Aerial photographs for surveying purposes are taken using special cameras of large format (called surveying cameras), producing original film negatives at a size of 23 X 23 cm.

Up to which size can you enlarge an entire aerial photograph or a part of it ?

Aerial photographs provided by Geomatics have been acquired using high-resolution aerial film and superior technology aerial photography systems. An aerial photograph with an original size (format) of 23X23 cm can be enlarged up to twenty times, reaching a giant poster's dimensions (4,60X4,60m). That is, if we have an aerial photograph at a scale of 1:5.000, we can enlarge part of or the entire photo up to a scale of 1:250.

How can I indicate the part of the aerial photograph that I wish to enlarge ?<

After choosing the aerial photograph which answers to your needs, please contact us to get a copy of it at a digital form, on which you will then indicate your area of interest and the desired enlargement factor.

Which is the difference between AeroHELLAS Basic and AeroHELLAS Pro products ?

AeroHELLAS Basic products are aimed at users who need aerial photographs not for mapping purposes, but rather for imaging, recognition and photo interpretation purposes and users interested in a poster, an enlargement of some part of an aerial photograph or just an aerial photo at a digital form.

AeroHELLAS Pro products are aimed at engineers and technical professionals in general, who wish to use stereoscopic aerial photographs for surveying and mapping purposes. AeroHELLAS Pro products are aimed at photogrammetric use and are available in form of either high-resolution digital images produced by photogrammetric scanners or diapositives on polyester based film which can be used on analytical stereoplotters. They are accompanied by all data necessary for documentation such as camera calibration data.

Both products are offered either as single (non-stereoscopic) or as stereoscopic images with a 60% overlap.

Which are the available formats of the digital aerial photographs ?

AeroHELLAS Basic products are available in JPEG format and 1.200 dpi resolution. AeroHELLAS Pro products are available in TIFF uncompressed format at a resolution of 14 μm (1814 dpi). In both cases aerial photographs are available in either CD-ROMs or DVD-ROMs.

What do the terms "digital printing" and "photographic printing" mean ?

The term "Digital Printing" means printing in plotters on photographic quality paper. The term "Photographic printing" means printing in a LAMBDA digital photographic printing system, on photographic paper, which is then developed according to the usual photographic procedures. Photographic printing produces much higher quality results.

Is it allowed to download aerial photographs from the site ?

Downloading aerial photographs from the site is not allowed.

Is it allowed to publish aerial photographs ordered through the WEB ?

Aerial photographs purchased through the WEB are GEOMATICS' intellectual property and are available for limited use only. Publishing aerial photographs or commercially using them in any way is not allowed unless a written permit is provided by GEOMATICS.

What do the terms "orthophoto image" and "orthophoto map" mean ?

An orthophoto image is an aerial photograph, which has been orthorectified, so as to have a uniform scale and geo-reference (meaning that it is connected to a system of coordinates). An ortho-photograph is produced by mosaicking orthorectified aerial photographs.

An orthophoto map consists of various ortho photographs integrated with vector data, such as contours, road or property outlines, location names e.t.c.

Ortho photographs as well as orthophotomaps are always available with georeference data and optionally with DTM data.