| (Data) Product |
An object that contains remote sensing data for a well known
scene on the earth. Within the Sentinel Toolbox, a product can
contain meta-data, geo-coding information, tie-point grids and
bands. All band raster datasets within a product have the same
pixel resolution and share the same geo-coding. |
| Band |
A spectral or geophysical raster dataset of a product. The
band's sample values are usually the measurements of a sensor. |
| Tie-point grid |
An auxiliary (geophysical) raster dataset of a product.
Tie-point grids usually provide less sample values than a band.
Missing values, with respect to the full pixel resolution of a
product, are obtained by a linear interpolation. The tie-point grid
data does normally not originate from the sensor which provided the
product's measurement data. |
| Geometry |
A geometric shape (point, line, polyline or polygon).
Geometries can be drawn on a scene view. |
| Mask |
Marks a region of raster dataset. Masks can be derived from an
expressions, a value range or a geometry. |
| Flag-Dataset |
A special band type which contains quality flag information.
Flag datasets always have an unsigned integer data type (8 to 32
bit). Flag values are encoded through one or more bits: A flag is
considered as set when a specific bit combination is met. Each
flag's metadata is stored in a corresponding flag coding
object. |
| Flag-Coding |
Flag codings are used to specify the bit positions of single
flags within an integer sample value of a quality flags dataset.
Each element in a flag coding provides the metadata for a flag such
as the name, description and a bit-index. |
| Index-Coding |
Index codings are used for classification bands. It maps a
sample value of the band to a class by using the value as index.
Each element in an index coding provides the metadata for a class
such as the name, description and the index. |
| Geo-Coding |
Provides the geodetic co-ordinates for a given pixel of a
product. An image is geo-coded if it is somehow possible to find
the geographical latitude and longitude values for any pixel. SNAP
products store their geo-coding information in tie-point grids or
bands. If a product has been map transformed, it is known to be
geo-referenced and as such, tie-point information is no longer
required. |
| Geo-Reference |
An image is geo-referenced, if any point in the image can be
found in a corresponding reference map by a linear transformation.
Every pixel in the image has the same size if expressed in map
units. Geo-referencing a geo-coded image includes image warping,
applying a well known map projection and pixel re-sampling. |
| Map |
Graphic representation of the physical features (natural,
artificial, or both) of a part or the whole of the Earth's surface,
by means of signs and symbols or photographic imagery, at an
established scale, on a specified projection, and with the means of
orientation indicated. |
| Map Projection |
Orderly system of lines on a plane representing a corresponding
system of imaginary lines on an adopted terrestrial or celestial
datum surface. Also, the mathematical concept for such a system.
For maps of the Earth, a projection consists of a graticule of
lines representing parallels of latitude and meridians of longitude
or a grid. |
| Graticule |
Network of parallels and meridians on a map or chart. A
geographic graticule is a system of coordinates of latitude and
longitude used to define the position of a point on the surface of
the Earth with respect to the reference ellipsoid. |
| Grid |
In connection with maps: a network of uniformly spaced parallel
lines intersecting at right angles. When superimposed on a map, it
usually carries the name of the projection used for the map that
is, Lambert grid, transverse Mercator grid, universal transverse
Mercator grid. |
| Pixel coordinates |
In the Sentinel Toolbox, pixel values always refer to the upper
left corner of the pixel. Pixel co-ordinates are always zero based,
the pixel at X=0,Y=0 refers to the upper left pixel of
an image and the upper left corner of that pixel. |
| Pixel value |
In general a composite of red, green and blue sample
values resulting in a colour as part of an image. Within the
Sentinel Toolbox, often synonymously referred to as the single,
geophysical sample value of a band or tie-point grid. |
| Geodetic co-ordinates |
Geodetic co-ordinates are given as latitude and longitude
values and always refer - if not otherwise stated - to the WGS-84
ellipsoid. The geodetic co-ordinates of a pixel, always refer to
the upper left corner of the pixel. |
