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

Overview
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.

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 slant range.

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 uses.

Clipboard Support
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.

ITU Filings
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 down.

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.

Dual-Mode Optimizer
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.

Software Support
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.