SATSOFT is used for communication satellite antenna design, analysis, and
coverage planning. Quickly assess antenna coverage and gain, conduct antenna trade studies,
develop shaped beam and multibeam antenna designs, and perform other satellite payload
engineering tasks. SATSOFT was written for the systems engineer as well as the antenna
specialist. Its graphical user interface was designed to enable users with even a basic
knowledge of antennas to use the software productively. Advanced tools will appeal to the
antenna specialist. If you need software to model satellite antennas, for GEO, LEO or MEO
constellations, SATSOFT was written for you. Please see our Products
page for the options that are currently available
SATSOFT Composite View
SATSOFT provides essential tools for planning your next GEO, MEO, or LEO satellite
communications system. SATSOFT has three basic types of views: Composite View has a
hierarchical tree in its left pane showing all objects that are currently modeled. The right
pane is a map of the earth showing antenna contours and polygons for all satellites.
Double clicking on an object in the tree opens either an Antenna View, for designing multibeam
antennas, or a Polygon View, for designing coverage polygons used in the design of the
antenna. Many tools are provided for various types of space-based communications systems
analysis and design. Basic features include map and contour plotting, coordinate conversions,
file import/export, boresight rotation, city pointing boxes, visibility contours, ground
tracks, EIRP tables, and other features. Context-sensitive help can be accessed at any time by
clicking on Help from any menu or dialog box.
SATSOFT Complements Your Other Software
SATSOFT is suitable for use by itself or with antenna modeling programs such as GRASP and
POS (TICRA Engineering Consultants,
Copenhagen, Denmark), or with your own modeling software. Although SATSOFT contains a powerful
set of analysis and design capabilities, the program is designed to interface to and
complement your other analysis software. Antenna patterns generated with SATSOFT may be used
with STK, for example.
|Simplified Antenna Coverage
Create a rectangular or triangular grid of beams over your coverage area, using the
Gaussian Beam Model provided with SATSOFT Standard, an optional reflector (SATSOFT/AR and SATSOFT/PO)
or array (SATSOFT/PAM) model,
or pattern data read from a file. Then create a grid of synthesis stations, and specify the
desired gain at each. Combine the component beams into a composite coverage using SATSOFT's
mini-max optimizer, which attempts to achieve the target gain at each synthesis station by
modifying the beam excitations. A dual-mode
optimizer is also available at additional cost.
A number of tools are provided to automate the coverage design process. Component beam and
synthesis station grids can be created automatically by filling a coverage polygon. A
graphical editor is provided to interactively add, delete, move, or re-specify the parameters
of single or multiple beams or stations just by pointing and clicking the mouse. What used to
take hours can now be done in minutes. What's more, computation is very fast, thanks to 32 bit
operation and highly optimized algorithms for drawing maps, contouring patterns, and computing
beams. Any number of component beams and synthesis stations can be handled simultaneously.
Every satellite may contain as many antennas as desired, and each antenna is a separate object
with its own design view. A tabbed workbook interface makes it easy to switch between views.
Contour Plots of EIRP, G/T, C/I, and Other Parameters
A fast contouring engine within SATSOFT produces plots quickly and accurately. Intelligent
auto-ranging and zoom-in/zoom-out functions make it easy to view a desired range of data. You
can also create plots at a precise scale for overlaying.
Conversion from directivity or gain to other parameters is accomplished by specifying a dB
offset to be applied to the antenna pattern prior to contouring. By applying slant-range loss
compensation, flux density contours can be computed. SATSOFT will also plot copol/crosspol
ratios for vector antenna patterns.
Maps From Any Altitude or Viewpoint
SATSOFT transforms antenna contours, geopolitical maps, coverage polygons, and other features
into any of nine different display coordinate systems, simply by making the desired choice.
The first four are variations of a perspective projection and correspond to the most commonly
used antenna coordinate systems. Two variations of Azimuth-Equidistant give true distance and
bearing from the map center to any point on the globe. Azimuth Equal-Area, Orthographic, and
Equirectangular (rectangular lat, long) projections are also provided.
Supports Antenna Data in (u,v), (theta,phi) ,Az/El, and El/Az Coordinate Grids
SATSOFT was designed to be very flexible in the type of antenna pattern data that can be
input. In addition to supporting the four major antenna coordinate systems, an input rotation
matrix allows you to exchange either axis of the input coordinate system. Thus, pattern files
written in terms of elevation or azimuth cuts, or u or v cuts, for example, can be
accommodated. Either axis can be inverted as well.
Antenna patterns can be calculated with SATSOFT, GRASP, POS or your own antenna modeling
programs. Patterns are imported from files and contoured in their own native coordinate
system. The contour points are then transformed to any of the nine coordinate systems
supported by SATSOFT. Whittaker/Shannon reconstruction of coarse input grids, if selected, is
performed automatically every time patterns are contoured. There are no extra steps to slow
you down. Use of this feature typically reduces disk storage and pattern computation time by
an order of magnitude or more.
Specify Antenna Boresight Rotation Interactively
Click and drag the antenna pattern to change its boresight. Alternately, the boresight may be
specified as a position on the map in terms of latitude and longitude, by specifying an
azimuth and elevation, or in terms of 3 Euler angles.
Slant-Range Path-Loss Compensation
This feature weights antenna pattern gain by a factor of (H/RS)2, where H is spacecraft
altitude, and RS is slant range to the point on the earth in the direction of the pattern
point. Flux density and carrier to thermal noise contours can be computed using this option.
SATSOFT fully accounts for spacecraft position and non-zero boresight angles when computing
Analytical Beam Generation
A Gaussian beam model is provided with SATSOFT Standard. Gaussian beams provide a very simple,
generic model for representing circular or elliptical antenna patterns. These have a parabolic
gain function in terms of dB. For accurate directivity and sidelobe prediction of reflector
antennas, however SATSOFT/AR and/or SATSOFT/PO should be used.
SATSOFT/AR is an analytic reflector model available at additional cost. This model represents
beams produced by an offset-paraboloidal reflector fed by an array of small, fundamental mode
circular or rectangular horns. The effects of illumination taper and spillover loss are
accounted for, but scan aberration and cross polarization are neglected. The model is useful
for preliminary work in shaping patterns, determining reflector size, minimum coverage area
gain, and average sidelobe level. It will most closely approximate offset reflectors with
large F/D ratios or small scan angles.
A physical optics reflector model
and analytical phased array model
are also available at additional cost.
User-Defined Coverage Polygons
Polygons can be created, imported, and edited in Polygon View. An extensive set of editing
functions is provided, enabling you to add, delete, rotate, copy, and move polygons or points
within a polygon. With SATSOFT Professional, Coverage polygons can be automatically expanded
by the pointing error of the satellite.
Coverage polygons can be created in any of the nine coordinate systems that SATSOFT supports.
Polygons can be fixed relative to the map, as with Equirectangular (longitude, latitude), or
can move with spacecraft position, as with perspective or azimuthal coordinate systems.
Digitize Existing Antenna Contours
Polygon View can treat polygons as either coverage polygons or as antenna pattern contours.
This enables contours of existing plots to be digitized and manipulated with SATSOFT, an
invaluable feature if pattern data is available only in hardcopy. For example, suppose an
existing on-orbit spacecraft is moved to a new orbital slot. What will the coverage look like?
What adjustments to antenna boresight will be necessary? Using a digitizing tablet with
SATSOFT, you can accurately copy antenna contours into the program. The procedure is first to
select the map projection and orbital slot corresponding to the hardcopy plot, and then apply
SATSOFT's three-point registration system to align it. Once entered, the data can be plotted
from any orbital slot, in any projection, with antenna boresight rotated as necessary to
obtain the desired coverage.
World City and Map Databases
A world map database containing political and geographical data is provided. Meridians and
parallels can also be plotted at arbitrary intervals.
A database of over 1600 of the largest cities in the world is also provided. Just point and
click to select the desired cities. A pointing box and/or designator can be plotted at each
city location if desired.
Visibility (Elevation) Contours
Any number of visibility contours may be drawn in any SATSOFT view. For each contour,
elevation to the satellite in degrees is entered. Specifying 10 degrees, for example, plots
the locus of points where the satellite is 10 degrees above the horizon. A sin space unit
circle may also be drawn.
Circular, Elliptical, and Rectangular Pointing Boxes
Pointing boxes are sized to represent pitch, roll, and yaw errors of the spacecraft. Points
are transformed so that they always form a locus on the map corresponding to the pointing
error of the satellite they are referenced to, regardless of the map projection selected.
Although generally elliptical in shape (in a perspective projection), SATSOFT will draw
circular and rectangular boxes of any size as well, providing flexibility for a variety of
Any view can be copied to the clipboard for pasting into any windows application that supports
windows metafiles (wmf), which includes Microsoft Office and many other applications. The
graphics are in vector format, so that the plots may be resized without loss of quality.
Screen graphics may also be written to a file in Windows Enhanced Metafile format.
Antenna patterns may be exported in ITU GXT format for filing electronically with the International
Telecommunications Union (ITU). GXT files may also be imported so that pattern contours
from the ITU's Space Radiocommunications Stations CD ROM database can be used with SATSOFT.
TICRA Software Compatibility
For antenna designers using TICRA modeling software, SATSOFT is the perfect complement,
providing support for GRASP antenna pattern and reflector geometry files (SATSOFT/AR or
SATSOFT/PO required for GRASP7 reflector geometry export). For custom developed or other
third-party software, pattern files are easily created to be compatible with SATSOFT, in
either ASCII or binary formats.
Use SATSOFT as a front and back end for multibeam GRASP7 simulations. Quickly set up the
reflector geometry using SATSOFT/AR or SATSOFT/PO, then export the geometry to a GRASP7 input
file. Import the resulting antenna patterns for further analysis with SATSOFT. You can import
a file of component beams produced by GRASP, then produce shaped coverages using SATSOFT's
mini-max optimizer and synthesis station layout tools.
Speed up your analysis and reduce storage an order of magnitude by using coarse pattern grids.
SATSOFT's built-in Whittaker Reconstruction feature can then be used to produce smooth
patterns. This requires only a single menu selection, and automatically performs the
reconstruction every time the patterns are contoured. There are no extra steps to slow you
SATSOFT can be used as an interactive front-end for POS reflector shaping software as well.
Create POS compatible PO-coverage grid files using SATSOFT's extensive graphics facilities.
Synthesis station properties including location, desired gain, weight, and polarization are
fully supported at multiple frequencies and polarizations. Then plot the resulting antenna
pattern contours with SATSOFT, overlaying the synthesis stations if desired.
A dual-mode optimizer is
available for multi-beam antenna designs which must accommodate a non-contiguous output
multiplexer. Beam excitations are constrained to be orthogonal, which is necessary for
lossless realization of dual-mode feed networks.
Many improvements to SATSOFT are being developed, so make sure to order an annual support and
upgrades (ASU) contract when you purchase the software. This provides automatic software
upgrades and technical support.