International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 1
Number 2
June 2007
Multidimensional Presentation of Radar Image
M. Waz
Polish Naval Academy, Gdynia, Poland
T. Stupak & A. Szklarski
Gdynia Maritime University, Gdynia, Poland
ABSTRACT: The modern navigation radar has no 3D visualization creation possibility. Digital signal
processing technology progress gave the new possibilities in radar data transforming process to many kinds of
digital picture representation. The picture saving methodes was upgraded last time and tools used during
picture transformation become popular and useful. For instance the RSC (Radar Scan Converter) digital
radar picture recording and transforming tool can be used to create new picture on line. The 3D radar picture
creating become easy and fast because of modern computer graphic techniques. The radar 3D digital picture
creating should be standardized with 3D digital chart creating by IMO, because the navigation near future will
be probably based on digital information created in digital devices.
The 3 dimension visualization is used in marine
navigation systems. Echosonders and sonars working
in hydroacustic systems under water environment
present in three dimensions.
Often vector map used multidimensional
presentation occurs. This presentation is used in
aviation and under water navigation. The producers
offered wider package of 3D chart conform to IMO
requirements. In the nearest future 3 dimensions
presentation maybe obligatory presentation on
navigation systems display. Part of these systems
work with radar and radiolocation data is sending in
digital form. 3D presentation of radar picture require
new technology of radar target build. In first step is
necessary compile digital form of radar signal.
The most of modern marine radars present digital
visualization in Cartesian coordinate axes. R
The radar picture is projected on computer or
liquid screen in form of square matrix with the same
numbers of pixel in lines and columns. This is the
raster form and it is reading in computer memory
like bitmap. BMP- is the bitmap net presenting one
or three color layer (one 256 level of gray; three
256 level of: red R, green G, blue B). In
CMYK computer graphic is possible to picture
record in four layers of colors. In modern marine
radars are used two or three basic color for marine
radar elements (target, water) and eventually one to
rest information (movement vector, boundary of
Radar picture storage in computer memory like
raster is continues data compilation which is
observation place function and it is changing with
hydro meteorological conditions, seaside line and
different objects. Continuous data compilation may
be a regular point net presentation, recorded like a
vector. Net points take steady balance on radar
screen and have steady geographical coordinates.
Each point of radar picture is shown like following
vector coordinate which gives information about
target. More convenient is radar picture built like un
regular points net with discreet value, which in next
step can create lines or areas.
All coastal lines and points describes
characteristic elements of the marine area create
representative radar picture matrix [3], [4], [5], [6].
The basic task to 3 dimension picture create is
digital radar signal storage which each pixel
coordinates give. This radar picture will be storage
like vector collection for 3D representative:
( )
ϕ, λ – pixel coordinate;
W gain level of radar target.
Or for picture in pole coordinate system:
( )
bearing (NR);
d distance (d
The basic task during 3D radar picture create will be
third coordinate build. Marine radiolocation station
gives information about altitude coordinate of
observed and tracked targets, but the radar picture is
created in 2D coordinate system map with target
altitude information. The sample of 3D screen is
small dimension mobile radiolocation station
MMSR 3D (made by RADWAR) shown on Fig. 1.
3 dimension radar presentations required digital
form signal transformation and 3 dimension graphic
application (i.e. OpenGl)
Fig. 1. Radiolocation station MMSR 3D (RADWAR)
Modern navigational radar is working like 2D
unit. In this unit isn’t possible to altitude information
used. Is target altitude information necessary for
marine navigation purpose? Gain of target echo
depends of cross section. This parameter non linear
depends from target dimensions. Third dimension of
target can be received radiolocation power signal.
This solution gives better capability of radar picture
visualization and presentation. Digital signal
registration (i.e. HP 54501A Navigation Department
M.U. in Gdynia) used can take digital information
about altitude characteristics from true object.
Digital analyze of these information give possibility
of plotting, tracking or searching object. Modern
computer visualization technique facility this
process. Radar picture can be stored in digital form
like vector with coordinates (α, d, W), where α and
d is bearing and distance to the elementary cell of
radar signal and W coordinate is amplitude of pixel
identity like radar target.[1]
Fig. 2. Video radar signal and its digital form
Radar picture digital form storage gives possibility
of its visualization. Present computer visualization
technique opens a wide range of its solution.
Presented picture can be shown with important
elements gain from research or used points of view
(special color). In multidimensional visualization
important points are well visible on the screen by
Bellow (Fig.3) 3D radar form of Gulf of Gdańsk
is compared with its 2D radar screen form. There are
shown weak and strong target. On the 3D picture
weak echo created by sea waves (noise) is visible
and it isn’t detected on 2 d screen. Gain level on
both figures is the same. Probably part of radar
picture elements important for research will be easer
detect on multidimensional presentation.
Fig. 3. 3D radar form
Multidimensional visualisation must be done in
real time. Its need computer program created 3D
pictures shorter then one radar scanner rotation (3 s).
The usage of OpenGL, DirectX library makes this
process possible.
If the radar signal is storage in 3D form for created
3D visualisation are used packed and programmable
interface (API Application Programming Interface).
Thanks for it is possible 3D code application create
working operation system control. These API are
DirectX graphic library made by Microsoft It working
in accordance with vector graphic principles. One
object is described by same triangular (in program
DirectX) and its coordinates.
The most important is order all objects from
farthest to nearest. DirectX program offered Z-
Buffer algorithm done this task. It is memory
structure storage coordinate Z (W for radar picture)
each pixel. For each screen parameter W in the pixel
is compared with this value from previous screen.
Next step is texture mapping its mean added 2D
bitmap to 3D triangular objects. Minimum two
different dimension bitmap are used. When objects
closed to observatory is used bigger bitmap and
when distance to the object growing up the bitmap is
changing for smaller. The library builds faster radar
pictures in 3D structure.
Fig. 4. Gulf of Gdańsk 3D radar screen
Modern navigational radar gives possibility 3D radar
picture visualization. Digital transformation of
electronic signals programs development created
possibility of radar data transformation to the
different digital form.
Used Radar Scan Converter radar picture can be
registered and transformed in real time.
Computer graphic application created easy
transformation radar picture to 3 dimension form.
3 dimension radar signal maybe used to radar
chart build in important for navigation safety areas.
These applications are needed to improve radar
visibility of small objects during meteorological
disturbances and created improvement of marine
safety used radar.
Stupak T., Wawruch R., Verification of the radar visibility of
small objects. Third International Congress on Maritime
Transport “Maritime Transport 2006”, Barcelona 2006,
Department of Nautical Science Technical University of
Catalonia, Proceedings, ISBN 84-689-8505-8, pp.1157-
Wawruch R., Stupak T., Radar Detection of Small Sailing
Yachts. 2nd Microwave & Telecommunications Research
Institute, German Institute of Navigation, Warsaw
University Radar Week in Poland, International Radar
Symposium „IRS2006”, Kraków 2006, of Technology,
Hamburg Hamburg University of Technology,
Proceedings, IEEE Catalog Number: 06EX1284, ISBN: 83-
7207-621-9, Warsaw 2006, pp. 523-526.
Wąż M., Methods of transformation radar pictures in compa-
rative navigation. XII Międzynarodowa, Konferencja
Naukowo-Techniczna INiHM AMW, Gdynia, 2000
Wąż M., Wykorzystanie obrazów radarowych w nawigacji
morskiej. Konferencja Naukowa WAT, Urządzenia i
Systemy Radioelektroniczne UiSR 2005
Wąż M., Nowak D., Wektorowy obraz radarowy. VI
Sympozjum Nawigacyjne. Akademia Morska w Gdyni,
Gdynia 2005r.
Wąż M., 3D Picture display for navigation radar. Annual of
Navigation No. 11; Gdynia 2006