|Analytical Graphics, Inc.
||STK Components is a family of class libraries that
leverage the STK desktop product by using its algorithms and file formats and
building off its analysis. The libraries are verified and validated against STK
as the benchmark. AGI expects Components to achieve the same numerical accuracy
as STK, and a large part of the test suite is dedicated to ensuring that. More
than 3,000 individual tests are run on every build of components using NUnit as
the framework. NCover informs the test group of any code that goes untested. If
a feature cannot be tested with STK, other methods are used. For instance, AGI
does limited testing against other data sources such as the Astronomical
Almanac. Engineers also test for specific well-defined results and for edge
cases (correct error handling, pathological cases, etc.) All told, AGI’s code
coverage is more than 90% with the remaining 10% tending to be error handling.
All AGI tests have built-in acceptance criteria on a pass-fail basis: AGI does
not ship unless all tests pass.
|Analytical Graphics, Inc.
||This document extends the Independent Verification and Validation (IV&V)
technical report prepared by the Aerospace Corporation, and shows that STK 9
meets or exceeds the benchmark specifications for STK 4. This document is limited
to tests of the High Precision Orbit Propagator (HPOP) and parameter and
coordinate-frame transformations, using test cases commensurate with those
published in the original Aerospace Corporation IV&V report. The software settings
that provide maximum compatibility with STK 4 as originally used with
Aerospace Corporation’s baseline tools are also discussed. The results show
that, using these software settings, the differences in results between STK 4 and
STK 9 remain at or below the suitability criteria used for STK 4 against Aerospace
|University of Colorado
||The University of Colorado has produced evaluations of the effectiveness of ODTK for performing orbit determination based on GPS measurements. Four reports have been completed to date covering the use of pseudo-range and carrier phase measurements inclusive of satellite attitude modeling and the use of navigation solutions as measurements in ODTK versions 1.1, 2.0, 3.0 and 4.0.
||2007 (v4.0) 2004 (v3.0) 2004 (v2.0) 2003-04 (v1.1)
||Sensis Corporation performed a Validation and Verification of AGI's aircraft flight-path modeling tool, Aircraft Mission Modeler,
by comparing a flight trajectory created within STK to an externally generated trajectory model. According to Sensis, "The Aircraft
Mission Modeler in STK provides the capability to accurately represent the flight trajectory of any aircraft based on user-provided
flight paths." Read more.
|Center for Space Standards & Innovation (CSSI)
||CSSI analyzed state vector propagation using differing flight dynamics programs:
GEODYN (Goddard, NASA, NRL, other)
GTDS (Goddard Trajectory Determination System, MIT)
HPOP (Analytical Graphics Inc., Satellite Tool Kit)
|John Draim, Aerospace Consultant
||In his paper "Satellite Constellations," presented at the 55th International Astronautical Congress, Draim compares STK to six other satellite orbit and constellation development tools. He calls it "without a doubt the most
advanced commercially available and reasonably priced computer product available to the satellite constellation designer. Draim generated all analytical figures for his paper using the freeware version of STK.
||The WMAP mission to the L2 libration point used STK/Astrogator for trajectory design, including calculating the launch windows, designing the phasing loops, targeting orbit insertion, operational maneuver planning, engine calibration, and contingency planning.
|The Aerospace Corporation performed an independent Verification & Validation of STK functions: high-precision orbit propagation, orbital parameter and coordinate-frame transformations, and access and visibility calculations.