System Requirements | What's New? | Transition Issues and Limitations | Online Help Resources

ODTK 4.0 Release Notes

Including Changes through Version 4.1.3

These release notes contain information on system and disk space requirements for installing and running OD Tool Kit; information on new capabilities and features introduced in the current version of OD Tool Kit, including issues resolved from the prior version; transition information -- cautions, workarounds and operational tips -- to help maximize your successful use of the product; and a brief introduction to online help resources.

Unless otherwise indicated, the information presented below reflects the state of OD Tool Kit as of version 4. Changes introduced in version 4.0.1, version 4.1, version 4.1.2 and version 4.1.3 are described in separate sections.

System and Disk Space Requirements

The following table sets out minimum and recommended system requirements for OD Tool Kit 4:

OD Tool Kit 4 System Requirements
Memory Disk Space Processor
Minimum 256 MB 1 GB 800 MHz
Recommended 512 MB 4 GB 2.0 GHz

An OD Tool Kit 4 installation requires 200-300 MB of disk space. Running a typical scenario, such as the Sapphire demo scenario that accompanies OD Tool Kit 4 (3 satellites, 5 trackers x 3 days), takes about 600MB disk space for simulator, filter and smother runs. During such a run the memory footprint of OD Tool Kit 4 is slightly over 110Mb.

What's New in OD Tool Kit 4?

Orbit Determination Tool Kit (OD Tool Kit) version 4 is built upon the same verified astrodynamics functions and coordinate conversions as STK and its modules. OD Tool Kit 4 is a matched set of modules, designed to provide orbit determination and analysis support for the entire life-cycle of satellite tracking systems. All phases of systems design can be supported with simulated tracking data, Monte Carlo analyses, and covariance analyses. OD Tool Kit 4 can produce results for satellite orbit parameters by processing one satellite at a time or multiple satellites simultaneously. OD Tool Kit is a stand-alone product, not an add-on module to STK.

The main products in this suite are a tracking data simulator, a state-of-the-art optimal sequential filter and a matched optimal sequential smoother. The sequential filter is designed to provide capabilities in support of routine satellite operations, including orbit determination, ephemeris prediction, and bias and maneuver/thruster calibration. The sequential filter produces a realistic covariance for system performance analyses, tasking optimization, and calculation of the probability of collision (in conjunction with STK/CAT). The optimal smoother provides high accuracy post-fit ephemerides in support of mission data products.

Particular care has been taken to ensure that regression tests to ODTK 3.0 are satisfied, that ODTK 3.0 scenarios will load and run in OD Tool Kit 4, and that ODTK 3.0 restart files will initialize in OD Tool Kit 4.

New Features

New features introduced with this release include:

GPS Phase Measurements

GPS Phase measurements have been added. Phase measurements are modeled as integrated Doppler in a unique (patent-pending) algorithm. Phase measurements can be processed as a single frequency measurement or in combinations of dual frequency (ionosphere corrected) and/or singly-differenced Doppler (receiver clock removed).

Satellite Attitude

Satellite attitude can be specified, either as an attitude file or as a set of constraints for body alignment. Given correct attitude information, the location of transponder and GPS receiver antennas can be defined in the satellite body frame and the effect of the offset from the center of mass will be correctly accounted for.

Finite Maneuvers

Several changes were made to finite maneuver processing. Multiple finite maneuvers can be specified for the same satellite with overlapping times, allowing the modeling of individual thrusters and thrust segments. Finite maneuvers can also be grouped under a permanent set of state parameters, so that the same thruster or thruster set can be calibrated over multiple maneuver events.

Atmospheric Density

Several choices for atmospheric density models have been included, including two variations of the MSIS model.

Multiple Antennas

GPS receivers can now support multiple antennas.

GPS Plugin

A GPS satellite selection plugin point has been added. This plugin point allows for the customization of the satellite selection algorithm during the simulation of GPS measurements.

Least Squares

Least Squares has been reworked. Least squares now recognizes thrusting between Stages, will process GPS measurements, and will process TDRS measurements (however, limited to one satellite in the least squares solution, with remaining satellites represented by reference ephemerides).

Filter Changes

A limited capability has been added to change filter states, model values, and process noise values at filter restart times. Satellites, facility bias states, and finite maneuver states can be added or dropped at restart times. Measurement biases, transponder biases, ballistic coefficient and solar radiation pressure coefficients can all be modified to revise the constant value to account for a persistent estimated bias, and the Gauss Markov sigma and the half-life can be modified. This new capability is intended to support operational applications where restarting from initial conditions is not an option.

TDRSS Forward Link Doppler

Forward link Doppler, also called 3L Doppler, has been added as a measurement type to complete the TDRSS measurement set. This data type is used by HST and TOPEX missions.

Capabilities Added and Issues Resolved From the Prior Release

The following table identifies limitations and issues that have been resolved in the current release, as well as new capabilities and improvements that have been added:

For convenience, this table includes all enhancements and resolved issues believed to be significant, including some that are discussed in more detail above.

New Capabilities and Resolved Issues
Tracking No. Description
00422 The Least Squares wizard default setting for start and stop times for a stage is now based on the times of available tracking data
05126 Several changes were made to least squares, including a new convergence criterion, optional divergence control, optional display of number of measurements, new optional data types (TDRS, GPS), and the option to stop the least squares process more easily.
05701 Least Squares run files now correctly set the Start and Stop time attributes.
05852 A problem with the modeling of multiple simultaneous finite maneuvers on the same satellite which could result in an incorrect computation of depleted mass has been resolved. The Initial Mass and Final Mass reported in the Finite Maneuver Summary report will reflect the total satellite mass expended across that interval due to all overlapping maneuvers.
08561 Customers can create a single large SP3 file from multiple smaller SP3 files using the new utility ConcatenateSP3Files.htm.

09825

When you load a scenario, it will now use the latest installed DynamicEarthData directory, thus picking up any changes you made with the Update Data Files tool.
11439 Support for one way (return link) TDRSS Doppler has been added.
12115 In addition to J2000 and True of Date, ODTK allows the initial state vector to be input in ECF (for Cartesian input only).
12171

The Uncertainity.ByComponent sigmas and the magnitude Uncertainity.MagnitudeAndPointing units for FiniteConstantThrust maneuvers were changed from acceleration units (m/s^2) to thrust units (kg*m/s^2).

Uncertainty units for Instant maneuvers were not changed; they remain in velocity units (m/s).

When an ODTK 3.0 scenario is loaded the user will see a MessageViewer warning that process noise acceleration units were changed to thrust units using the satellite mass.
12172 Renaming a report style in the static product builder while the report is being edited will generate an error concerning a bad filename. This indicates that the file is in use. The user can either rename the report style using Save As, or exit the editor and perform the rename through the static product builder.
12348 The IRI2001 is now up-to-date with the latest version from NASA. Simulations made with the ionosphere included will show slightly different results.

12456

The ODTK Least Squares capability now supports processing TDRSS measurements (4L Range, 5L Doppler) for a user satellite.
12493 ODTK now allows one set of finite maneuver states across multiple maneuvers, through the addition of a new satellite attribute, PermanentManeuverStates, and a new finite maneuver attribute, StateAssociation.
12523 The default step size for the custom simulation interval is now the simulator step size. Prior to this release it was fixed at 1 minute.
12567 Error messages have been updated to use the correct max length count (64 at present); now and in the future, as long as the coded constant AgCMaxNameLen is the only thing changed, the messages will use it (rather than having a hard coded value).
12597 The force model plugin feature has been modified and extended. Plugin models written for OD 3.0 will have to modified because the interface has changed. While it is not our practice to change interfaces, this change was necessary to prevent the application from aborting due to errors in the plugin script. New features have been added and a new section has been added to the online help.
12601 Multiple simulators in one scenario can lead to incorrect dynamic displays for "RIC Differences" and "diff" and "diff/sig" fields. To get the correct dynamic display, be sure that the only simulated measurements file that is Enabled under Scenario.Measurements.Files is the file to be used by the filter.
12786 The MeasurementProviders section of ODTK Prefs.xml now has a version number. ODTK will use the content of the section only if the version string matches exactly.
12596 A new capability has been added to the Initial State Tool to allow propagation of the satellite orbit forward or backward from the current epoch to a new epoch. The tool replaces the Orbit State in the satellite object properties with the satellite position and velocity at the new epoch time.

13198

In a custom graph, the initial date/time is no longer included in the X-axis label if you create a graph where the X axis is not time.
13564 The simulation and processing of space based two way range measurements was corrected to properly edit data based on the grazing altitude limit on the tracking satellite.
14028 ODTK now can display all residuals for one satellite in one graph, using a unitless ratio of residual to sigma.
14108 Satellite epochs and filter/simulator/smoother start/stop times (among others) can now be controlled by a set of attributes on the scenario object.
14206 A problem was fixed in the State History Dumper by increasing the precision carried in time strings. Time strings now have the format:
mm/dd/yyyy hh:mm:ss.sssssssss
14208 There is a new attribute in the STKEphemeris attribute section for filter, simulator and smoother objects named Acceleration, which is a Boolean flag that causes the acceleration to be written to the STK ephemeris (.e) file. This information is used during interpolation in STK 6.2 Additionally, the Acceleration attribute was added to the satellite object's EphemerisGeneration attribute section.

14875

Least squares now processes maneuvers as specified in the satellite object. Least squares is not as robust as the filter in solving for the orbit in the presence of a known maneuver; however the option is provided forcompletenesss.
16143 If the user sets an estimated parameter to have zero sigma, then the filter will not include this parameter in state space. This change prevents matrix inversion errors in the smoother. The affected parameters are density scale factor, ballistic coeff sigma, SRP sigma, maneuver sigmas, facility location sigmas, transponder bias sigmas, measurement bias sigmas.
16427 An error in the tropospheric refraction model was corrected. The user may notice changes in residuals for low elevation data measurements.
16431 All measurement loader scripts that previously had "GetAppConfig = m_scope" in the GetAppConfig() method now need to have "Set GetAppConfig = m_scope".
16452 The simulator will include all estimated parameters in the state regardless of whether or not they are deviated during the run.
16486 The force model plugin interface was rewritten to trap script errors without causing the application to abort. Plugin examples supplied with version 3.0 will not work in version 4. You should use the version 4 sample plugins when writing your own force model plugins.
16552 The Static Product Builder now has scroll bars when parts of the Static Product Builder are clipped. Also, a menu button control that displays a popup menu has been added. The original seven buttons in the Outputs page have now been consolidated down to two menu buttons to conserve screen real estate. One menu button contains the Add Graph, Report and Export commands and the other contains the Edit, Copy, Copy To and Delete commands.
16734 The General Relativity Acceleration model has been updated to IERS 2003.
16791 An issue with ODTK requesting licenses associated with STK (PRO, Terrain,Advanced VO) which caused license conflicts in installations using network licenses has been corrected. ODTK no longer requests these licenses.
16883 An input for the maximum order of the geopotential to be used in the computation of the variational equations has been added. This capability improves the performance of the filter for GEO satellites whose motion is highly dependent on the tesseral harmonics. (A recommended setting for GEO satellites is degree = order =3.) Prior versions were limited to using only zonal harmonics in the variational equations.
16954 In ODTK 4 in Perl Script the OD Home directory attribute $ODTK->Children("STKHOME") has been replaced by $ODTK->Application->STKHome->Value. The following attribute will also work but os not recommended: $ODTK->Application("STKHome"). Also please note that the STKHome and STKDb attributes are now additionally available as InstallHome and UserHome, respectively. There is no intention of removing STKHome or STKDB.
16989 A problem with the estimation of multiple simultaneous finite maneuvers on the same satellite, which could result in ODTK crashing, has been resolved.
17223

OD Tool Kit provides a set of capabilities designed to help the analyst make changes to an operational scenario at a Restart time, without having to reinitialize the filter. These actions change the dimension and content of the Filter state space, and so are called Flexible State Space options. Several use cases define the Flexible State Space options that are supported. Assume that: a multi-satellite simultaneous filter and smoother have been running, a set of restart records exists for the filter, and the analyst wishes to modify the filter. Then the analyst may want to make any of the following changes to the scenario without having to reinitialize the filter:

  1. Add a new satellite - i.e. a new launch for the constellation
  2. Delete a satellite - i.e. satellite is deorbited or otherwise retired
  3. Replace a satellite position and velocity. (Maneuver data for the satellite that is maneuvered is not available, but the satellite operator can provide a new post-maneuver state vector.)
  4. Add a ground station or a GPS receiver - i.e. new terminal available
  5. Delete a ground station or GPS receiver - i.e. it is retired
  6. Change the solution vector - i.e. now solve for SRP/Drag/Bias or turn off the solution of SRP/Drag/Bias
  7. Change the state statistics - i.e. the half-life or sigma on SRP/Drag/Bias/Transponder/etc.
  8. Add a measurement type to the filter with new statistics
  9. Delete a measurement type altogether
  10. Add new finite maneuver events
  11. Remove obsolete finite maneuver events
  12. Change the constant bias and corresponding bias sigma for facilities or transponders

All of these capabilities are fairly easy to provide in a Filter application; one simply drops states from or adds states to state space, and if a state value is changed, the cross-correlations to other states are zeroed. The challenge is to maintain the integrity of the associated processes, such as Restart File, Smoother, and Reports and Graphs in the presence of a Filter state space that changes in size and content; otherwise the covariance will suddenly have zero cross correlations. As of the current version of OD Tool Kit, Flexible State Space events can only occur at a restart time. In general the analyst requests these actions by:

  • Editing the scenario object properties in the white panels
  • Restarting the filter at a selected restart time

Multiple flexible state space actions can be exercised at any one time; however, the same object cannot be added and dropped at the same restart time.
17285 When states are dropped or added between filter runs, and you want to smooth over multiple rough files with non-matching states, there can be no active finite maneuvers at the time of the state size change.
17627

The attribute type listed if the use-right clicks on the attribute name is usually correct. However for children of elements of lists, the attribute type may not be correct. For example:

  • If you get attribute information on Satellite.MeasurementStatistics it will be SET (which is correct)
  • If you open MeasurementStatistics box and get information on its root element it will be SET (which is now correct)
  • If you get attribute information on its "Element 0" it will show the type as SET, which is wrong; it should be SCOPE according to the Scripting Tool.
  • Attribute information for the children of the "Element 0" is correct.
17707 Do not use overlapping rough files with a state change if a finite maneuver is active.
18059 An error in the initial covariance for finite maneuver direction states has been corrected. The prior initial covariance was too large by a factor of the square root of two.
18060 The gauss markov sequences associated with the estimation finite maneuver states have been changed to remain active at all times during the execution of the filter and smoother. In prior versions of ODTK, the GM sequences for maneuver states were only active during the maneuver interval. This change, which will produce minor changes in the maneuver estimates, was made to establish consistency between maneuver estimates generated using permanent maneuver states and estimates generated using unique maneuver states.
18245 Please note that attributes such as Values under Filter.Restart.GaussMarkovUpdates that are typed as "Real" cannot be set in scripting with a "set". "Set" is used for Quantity types. For Real types, use direct assignment (list(a).BiasSigma = 270) or list(a).ConstantBias = ODTK.NewQuantity(270,"m").GetIn(list(a).BiasUnits).

Transition Matters and Unresolved Issues

This section presents transition issues of importance to the user, including operational tips and caveats to help smooth the path to successful use of OD Tool Kit, as well as a list of limitations and unresolved issues of which the user should be made aware.

Transition Matters

It is suggested that you review the following list of cautions, workarounds and operational tips before using the current version of OD Tool Kit:

  • Loading Scenario workbooks which have the scenario name followed by a .wsp extension may not work properly in some situations, for instance, if HTML pages referenced by that workbook have been moved or removed. By updating the windows when loading and resaving the scenario, the problems should be corrected. Alternatively the user, before opening the scenario, may manually delete the scenario .wsp file using Windows Explorer.

  • Currently the simulator does not simulate the effects of geopotential errors, but the filter error covariance does account for geopotential errors. This problem does not affect the processing of real data. If one looks carefully at the filter response to processing simulated data, the error magnitudes of filter orbit errors are smaller than is indicated by associated orbit error root variances.

  • As currently defined, the Atmospheric Density Estimate, Solar Radiation Pressure Estimate, Transponder Bias and Ballistic Coefficient graph styles do not generate sigmas for simulated data. However, if you generate one of these types of graphs with a simulation file as input, the legend will contain references to sigmas, and a straight line purporting to represent sigma values will appear in the graph. These should be ignored, since there is no sigma data in the input file. To remove the spurious references and the line from the graph, right-click on the graph, select Properties, select the Series tab, select the series to hide and uncheck the 'visible' box.

  • Help on the OD Tool Kit Report Viewer is not available directly from that interface. However, access to the Crystal Reports Help system is provided via the OD Tool Kit Help system. In the Contents tab, select Reports & Graphs -> Reports -> Static Reports, and click on the link to Crystal Reports.

  • For optimal performance, only single-table reports should be generated. Graph styles support a single table only.

  • Troposphere range refraction error is currently modeled in the filter, but deviates are not applied by the simulator. Consequently, filter range residual ratio histograms derived from simulated range data will be somewhat peaked, when compared to the Gaussian density function. However, troposphere range refraction is modeled in both the filter and the simulator.

  • The control of GPS measurement types in the current release is subject to certain limitations. The selection of measurement types must be made in the satellite attribute MeasTypes. The filter can model GPS measurements exactly as simulated, which is the simplest case. However, the filter can process these measurements in different ways, as single differencing (SD), and/or as dual-frequency (DF) corrected measurements. These alternative methods require more manual input by the user, requiring that MeasTypes have one setting to run the simulator and another to run the filter. In addition, various combinations of pseudo-range cannot appear in MeasTypes simultaneously; see the online Help system for the matrix of valid combinations.

  • If you create your own tracking data providers, it is necessary to update them, since the Measurement Provider Script interface has changed. Otherwise, the old tracking data provider scripts will not work. This change was made in order to accommodate the new GPS measurement types and improve general flexibility related to measurement modeling. Reference the several sample scripts in
<Install Directory>ODTKD\AppData\Scripts
as well as OD Tool Kit Help for examples and descriptions. Specific changes include two changes in the measurement type enumeration. Custom scripts must be updated according to the following if GPS navigation solutions are being loaded:
Meas Type Description Old Value New Value
eMTGPSNav_C1 CA Nav Solution 61 81
eMTGPSNav_DF Dual Freq Nav Solution 62 82
  • If you load a scenario saved with OD Tool Kit version 3.0 or a prior version, and then save it, it will be saved as an OD Tool Kit version 4 scenario and cannot be loaded back into prior versions.

  • The addition of the ground-based range representation options OneWay and TwoWay have a potential impact on running IOD. If you read an IOD object from an OD Tool Kit version prior to 3.0, in order to run the IOD process you must be using the OneWay representation. Since the default in OD Tool Kit 4 is OneWay, this will not be an issue unless you specifically change the value to TwoWay.

  • As part of transitioning OD Tool Kit scenarios from one version to the next, you should pay special attention to files being used for EOP, solar flux and ionosphere modeling. These files are specified in the EarthDefinition section of the scenario attributes. If you load a scenario created in OD Tool Kit 3.0 or a prior version into OD Tool Kit 4, the files specified in the older version will be found and will continue to be used. While this is desirable for some cases, such as performing regression tests, you will probably want to update these file locations to point to files associated with OD Tool Kit 4. These newer files are the ones which will be updated by the Update Data Files tool in OD Tool Kit 4.

  • From release to release, the contents of database tables used in the definition of report and graph styles may change, usually through the addition of new elements to the record definitions. These changes can impact the content of custom reports styles created by the user. Before attempting to use a report style generated with a OD Tool Kit 3.0 or a prior version with OD Tool Kit 4, a Verify Database operation should be performed and a new copy of the report style should be saved to a new directory. Overwriting the old style will cause that style to work incorrectly with the prior version of OD Tool Kit. The Verify Database operation is performed by highlighting the report style in the Static Product Builder, clicking on the Edit button then right clicking on the Database Fields and selecting Verify Database.

  • Since OD Tool Kit 3.0 graph styles are not compatible with OD Tool Kit 4, a tool has been provided to convert your 3.0 custom graph styles to 4.0 graph styles. The tool is called ODTK_Style_Update30To40.pl, and is found in your install area under AppData\Scripts. This tool will convert all graph styles in the designated directory and store them to a new directory. It is recommended that you use a different folder for output, so that your 3.0 graph styles are not overwritten.

  • Large file limitations in graphing: Due to an addressing limitation in WIN32, graphs can fail when any data file size exceeds 2 GB. This limitation applies to any file, including the input database or the intermediate file constructed by ChartFX from the database. If the intermediate file is too large, the suggested recourse is to use data limiting or reduce the time period on the inputs tab of the Static Product Builder.

  • During simulation of GPS measurements, if a GPS selection plugin is being used, but fails, the simulator will continue with a default selection which simply picks the first 4 satellites. When using a GPS selection plugin to simulate measurements, check the message viewer carefully for plugin failure messages.

  • If you change the Gauss Markov parameters or the Constant value of a state variable in the GaussMarkovList during Restart, then the corresponding object properties (e.g. tracker MeasurementStatistics, satellite ForceModel parameters, transponder bias) are also changed to match the Restart state values. You must save the scenario to preserve the object properties settings and restart file settings; failure to do so will result in modeling errors in subsequent filter runs.

  • The following table shows changes in the tracking data interface between version 3.0.3 and the current version:

ODTK 3.0.3

ODTK 4.x

ODTK.Application

ODTK.Application

ODTK3.Application

ODTK4.Application

AgAttrAutomation6.AgAttrBuilder

AgAttrAutomation6.AgAttrBuilder

AgMach10_4.OLEDBDataSource

AgMach10_6.OLEDBDataSource

AgMach10_4.AgODObsSet

AgMach10_6.AgODObsSet

AgMach10_4.AgODObsSetCollection

AgMach10_6.AgODObsSetCollection

AgOD4.AgODTrackingIDList

AgMach10_6.AgODTrackingIDList

AgMach10_6.AgODRealList

AgOdtkPlugin6.AgOdtkPluginSite

IAgODProvideTrackingData4.AgODGenericObs

IAgODProvideTrackingData6.AgODGenericObs

IAgODProvideTrackingData4.AgODProvideB3TrackingData

IAgODProvideTrackingData6.AgODProvideB3TrackingData

IAgODProvideTrackingData4.AgODProvideCobTrackingData

IAgODProvideTrackingData6.AgODProvideCobTrackingData

IAgODProvideTrackingData4.AgODProvideGenericTrackingData

IAgODProvideTrackingData6.AgODProvideGenericTrackingData

IAgODProvideTrackingData4.AgODProvideGeoscTrackingData

IAgODProvideTrackingData6.AgODProvideGeoscTrackingData

IAgODProvideTrackingData4.AgODProvideGPSNavTrackingData

IAgODProvideTrackingData6.AgODProvideGPSNavTrackingData

IAgODProvideTrackingData4.AgODProvideILRSTrackingData

IAgODProvideTrackingData6.AgODProvideILRSTrackingData

IAgODProvideTrackingData4.AgODProvideLanceTrackingData

IAgODProvideTrackingData6.AgODProvideLanceTrackingData

IAgODProvideTrackingData4.AgODProvideRINEX_SD_TrackingData

IAgODProvideTrackingData6.AgODProvideRINEX_SD_TrackingData

IAgODProvideTrackingData4.AgODProvideRINEXTrackingData

IAgODProvideTrackingData6.AgODProvideRINEXTrackingData

IAgODProvideTrackingData4.AgODProvideUTDFTrackingData

IAgODProvideTrackingData6.AgODProvideUTDFTrackingData

AgHtmlServer.AgHtmlServerInitOD30

AgHtmlServer.AgHtmlServerInitOD40

HTML Utilities that are run inside ODTK:

window.external.CreateObject("AgHtmlServer.AgHtmlServerInitOD30")

window.external.CreateObject("AGI HTML Server")

Users that have custom scripts can either update them with new ProgIDs or use the *.wsc examples under AppData/Scripts to change their code to dynamically read ProgIDs from ODTK\AppData\Scripts\MeasProviders\WindowsScriptComponents\CreatODDBObjects.txt, which we update with the latest ProgIDs for every release.

Unresolved Issues Affecting the Current Release

The user should be aware of the following limitations and unresolved issues affecting OD Tool Kit as of the date of this release.

Unresolved Issues
Tracking No. Description
16334 Smoother does not work on filter solutions containing only GPS receiver clock states.
17253 Changes to user plugin attributes provided through scripting may not be recognized. User provided plugin scripts can declare parameters which are then available for editing through the normal ODTK object properties interface. If these parameters are modified from scripts via the ODTK automation interface instead of through the object properties interface, they may not properly configured when the plugin is called.

Changes Introduced in Version 4.0.1

The following information applies to OD Tool Kit version 4.0.1.

Capabilities Added and Issues Resolved in Version 4.0.1

The following table identifies limitations and issues that have been resolved in the current release, as well as new capabilities and improvements that have been added:

New Capabilities and Resolved Issues in Version 4.0.1
Tracking No. Description
18763 Minimum values for doppler, 3L, 5L doppler count intervals were increased from 1.e-6 sec to 0.001 sec to prevent occasional problems due to loss of precision in interpolating reference ephemerides.
18790 A problem was corrected loading ODTK 3.0 workbooks, which would occasionally cause Welcome and Start page errors.
18822 A problem with default GPS receiver boresight calculation, which was used when there was no antenna on the receiver, has been corrected.
18947 A PERL script example is now included in ODTK installs.
19022 A problem in the filter that resulted in the inability to generate smoother information after the time period for objects in the scenario had been changed by a large amount (several years) has been corrected.
19121 The SP3_to_Ephem utility no longer requires the analyst to enter leap seconds; the data is retrieved automatically.
19177 An error in the conversion of dates at the start of the leap second (limited to the instant of the start of the leap second) has been corrected.  Prior to this correction, tracking data with a time tag exactly at the instant of the start of the leap second would have been interpreted as having occurred at the end of the leap second. The probable result of this would have been the rejection of the tracking data at that instant by the filter.
19202 A problem in sorting data for reports in the presence of a leap second has been corrected.
19232 A problem that arose when running the filter in restart mode across a leap second (abnormal termination of ODTK) has been corrected.
19252 A problem was corrected involving incorrect accelerations in ephemeris files. The two-body accelerations are now added into the values in the ephemeris files.
19324 The use of local times for input in the vicinity of leap seconds using the Gregorian LCL (LCLG) and Julian LCL (LCLJ) date formats has been corrected. Times after the start of the leap second until the end of the local day were previously interpreted incorrectly in these formats such that the leap second was assumed to be at the end of the local day. The leap second is now correctly interpreted based on the UTC time of the leap second.
19348 The Saphire demo scenario now outputs truth and filtered ephemeris to the correct directory.
19416 The local time zone for ODTK was not previously set, which resulted in local time inputs (LCLG, LCLJ) being interpreted as GMT. This has been corrected.

Changes Introduced in Version 4.1

The following information applies to OD Tool Kit version 4.1.

Installation on a Network Fileserver

A PDF document with instructions for installing OD Took Kit on a network fileserver accompanies this release.

Capabilities Added and Issues Resolved in Version 4.1

New features in OD Tool Kit 4.1 provide some of the fine details in modeling required by very high accuracy missions. These include:

  • facility motion models
  • force models for smaller effects
  • a new atmospheric correction model

IERS standard facility motion models have been added, including:

  • tectonic plate drift
  • displacement due to solid earth tides and polar tides
  • displacement due to ocean loading.

Earth albedo and thermal radiation pressure has been added to the force model suite. The Marini-Murray atmospheric correction model has been added to be used in laser ranging applications. We have extended the ILRS (International Laser Ranging Service) definition of Merit II format to allow for infrared lasers. A new measurement type has been added for Normal Point Range (NPRange) to accommodate ILRS Normal Point data in support of satellite laser ranging operations.

Space Based Azimuth and elevation (SBAzimuth and SBElevation) have been added to support future space based radar studies. SBElevation is the angle from the local horizontal plane (the Plane normal to the radius vector), positive above the plane. SBAzimuth is defined in the local horizontal plane, measured from the instantaneous earth fixed north, positive to the east.

The following table identifies limitations and issues that have been resolved in the current release, as well as new capabilities and improvements that have been added:

New Capabilities and Resolved Issues in Version 4.1
Tracking No. Description
18139 The user can sort the elements of FiniteManeuver and InstantManeuver. The Finite Maneuver list is sorted into chronological order, using maneuver start time. Impulsive maneuvers are sorted into chronological order using CentroidEpoch.
19464 The option "/prec" has been added to ODTK.InitialStateTool function. Example: ODTK.InitialStateTool("EPH",ephFileName,"","/prec 0.000001")
20150 A problem viewing Dynamic Displays in single-step mode has been corrected.
21113 It is now possible to reset the current user, which will allow the designation of a new User area.
21276 A new measurement type called NPRange is provided, which assumes ILRS standard Normal Point laser ranging data. The Marini-Murray atmospheric correction model has been included which requires temperature, pressure, humidity and laser wavelength embedded in the tracking data. Attributes have been provided to allow simulation of NPRange data, allowing the user to specify default values for temperature, pressure, humidity, and laser wavelength.
22299 The complete IERS 2003 station motion model has been added as an option for modeling the location of ground facilities. This model includes the effects of tectonic plate motion, solid Earth tides, ocean tide loading and the pole tide.
22305 The Static Product Builder's Stop button will stop any product during generation, and if a data product list is being executed, the Stop button will halt execution of the entire data product list.
22320 A new utility has been defined to convert ILRS Normal Point format to Merit II format and to sort the data.

Unresolved Issues Affecting Version 4.1

Issues affecting the current version include the following:

  • When running a script to modify white panel objects, it is a good practice to close the white panel object first. This is particularly true of sub-sub panels such as finite maneuvers, IOD, Least Squares, etc. White panel refresh rates conflict with script execution rates.
  • Execution of an invalid scripting command can cause white panel errors for which the only recovery is to close the application and reopen. The use of debugging scripts with small dummy scenarios to prevent loss of valuable data is recommended.

The user should be aware of the following additional limitations and unresolved issues affecting OD Tool Kit as of the date of the 4.1 release.

Unresolved Issues in Version 4.1
Tracking No. Description
20808 Because of various issues affecting the use of the State Transfer Tool Wizard in situations involving multiple filters and GPS clocks, this tool will be discontinued in the next release of OD Tool Kit (version 5.0). Users with questions should contact AGI technical support.

Changes Introduced in Version 4.1.2

The following information applies to OD Tool Kit version 4.1.2.

Capabilities Added and Issues Resolved in Version 4.1.2

The following table identifies limitations and issues that have been resolved in the current release, as well as new capabilities and improvements that have been added:

New Capabilities and Resolved Issues in Version 4.1.2
Tracking No. Description
22431 The internal OASYS tracking data provider (reader only) is now available.
22431 The ephemeris generation function of satellite objects has been modified to always use the initial state of the satellite as the initial condition for ephemeris generation. Prior versions would simply interpolate the specified reference trajectory if the EstimateOrbit flag on the satellite was set to false. The behavior of the satellite ephemeris generation function has not changed the case where the EstimateOrbit flag is set to true.
23656 The ephemeris generation function of satellite objects has been modified to always use the initial state of the satellite as the initial conditiona for ephemeris generation. Prior versions would simply interpolate the specified reference trajectory if the EstimateOrbit flag on the satellite was set to false.  The behavior of the satellite ephemeris generation function has not changed the case where the EstimateOrbit flag is set to true.
24182 A condition which resulted in an abnormal exit of the application, when a simulator run was performed with orbit and density deviations turned off and ballistic coefficient deviations turned on, has been corrected.
24183 Incorrect checks during simulation on the simulator ErrorModeling.DeviateTranspDelay and ErrorModeling.DeviateMeasBiases setting, which could erroroneously result in zero initial deviates, have been corrected. Simulations could only have been affected if one or both of these settings were set to true and the ErrorModeling.DeviateSolarP was set to false. The addition of process noise related deviations throughout the rest of the simulation was not affected.
30312 A memory leak of HPOP's reflection model name has been corrected.
31148 ODTK is now compatible with Internet Explorer version 7: Running Installed Utilities on the Start Page no longer generates an error message.
31258 An error in the application of finite maneuvers that span the filter stop time, for the case where ephemeris prediction is requested as part of the filter run, has been corrected. In prior versions, the finite maneuver was not continued after the end of the filter span into the prediction interval. Note that this problem only affected the ephemeris prediction for the run that ended during the finite maneuver. Subsequent filter runs starting from restart records correctly applied the remainder of the finite maneuver.
31283 The application no longer aborts on restart during a finite maneuver.
31289

An error in the configuration of the force model used to generate acceleration values for generated ephemeris files has been corrected. The error affected reported acceleration values from a restarted filter when an estimated finite maneuver was active at the restart time. The error also affected the reported acceleration values from the filter after measurement updates.

In addition, an error in the configuration of the force model used during Doppler processing has been corrected. The error affected Doppler tracking data processing during an estimated finite maneuver.

31521 GPSCatalog.txt has been updated to the December 1, 2006 status of the GPS constellation.
31523 Dynamic Earth data files have been updated to December 1, 2006.
31570 The minimum grazing altitude constraint associated with TDRSS relay satellites is now considered during the simulation and processing of 4 Legged Range, 5 Legged Doppler and 3 Legged Doppler measurements. Previously, a hard coded value of 64 km was used.
31571 Ephemeris processing has been speeded up, with a reduction in the pause at the end of long simulator, filter and smoother runs.
31572 A memory leak when reading the flux file reader class has been corrected.
31574 A memory leak was fixed in HPOP plugin calls that returned data through the use of an array.
31575 An error in the measurement partials for Doppler measurements for deep space satellites has been corrected. This error only affected satellites orbiting at distances greater than 10 Earth Radii, which is well beyond the geostationary belt.
31576 DOP computations performed by the GPS Satellite Selection Plugin now work correctly.
31577 The GPS SatSelect plugin Date_Array function now returns the hour correctly.
31578 Aberration computations have been added to the ground based AzEl measurement models. The facility aberration setting will be honored by the measurement model when the 'use light time delay' flag on the measurement statistics attribute is set to true.
31580 An error in the diurnal aberration computation for ground based right ascension and declination measurements has been corrected.
31581 The loading of Herrick Gibbs IOD objects has been speeded up.
31848 Data limiting for Differenced measurements now works properly.
31850 Data Provider performance has been improved when retrieving MeasHistoryElement data.
31851 Performance when processing multiple measurement files has been improved.
31852 A memory leak in Initial State Tool ephemeris generation was fixed.
31854 The simulator will no longer abort if the HPOP integrator throws an exception when a satellite is below the perigee limit or atmosphere cutoff.
31855 The Data Provider calculation of the "Total Atm Density Est" value in the SatelliteState Table has been corrected.
31859 A problem with processing simulated TDRS 4 way range when the observations were saved to the generic obs format (.gobs) and the EditOnDoppler attribute of the 4 way range measurement statistic was turned on has been resolved. In prior versions, the 4 way range measurements would have been rejected citing invalid doppler measurements.
31864 Smoother instant maneuver names in the summary report have been corrected.

Unresolved Issues Affecting Version 4.1.2

The user should be aware of the following additional limitations and unresolved issues affecting OD Tool Kit as of the date of the 4.1.2 release.

Unresolved Issues in Version 4.1.2
Tracking No. Description
31740 Only SP3 GPS ephemeris sources are supported in ODTK 4.1.2. SEM and YUMA support will be provided in ODTK 5.

Changes Introduced in Version 4.1.3

The following information applies to OD Tool Kit version 4.1.3.

Capabilities Added and Issues Resolved in Version 4.1.3

The following table identifies limitations and issues that have been resolved in the current release, as well as new capabilities and improvements that have been added:

New Capabilities and Resolved Issues in Version 4.1.3
Tracking No. Description
33143 An issue has been fixed where the smoother would abort if a particular combination of events were encountered: (1) when smoothing across multiple rough files, (2) with state space changes during that time, (3) using an acceleration history file for a maneuver, and (4) the smoother performed a prediction.

Online Help Resources

The current version of OD Tool Kit is shipped with the following online help resources:

The OD Tool Kit Help System

The OD Tool Kit Help system appears in the Microsoft HTML Help Viewer, which uses components of the Microsoft Internet Explorer to display help topics and navigational tools. The latter are accessible from the following tabs:

  • Contents - Click on the book and page icons to find the topic of interest.
  • Index - Scroll down the list or begin typing the name of the index item in the textbox. When the item you are seeking appears in the list, double-click it or highlight it and click the Display button. If the item is found on more than one help page, a window listing the applicable pages will display.
  • Search - Type in the word or phrase for which you wish to search. To specify an exact phrase, enclose it in double quotes; otherwise, any page containing all of the words in the phrase (not necessarily contiguous) will be listed. After typing in the search term, either press the Enter key or click the List Topics button.
  • Favorites - This tab lets you bookmark help topics to which you might want to refer frequently. Clicking the Add button places the name of the currently displayed help topic in the list. To delete a topic from the list, select it and click the Remove button.

Context-Sensitive Help

F1 Help for OD Attributes

To display context-sensitive help for a property of an OD object, select it in the Object Properties window for the object and click the F1 key.

Help Buttons for Report and Graph Windows

Help buttons are available for the Static Product Builder, the Dynamic Product Selector, the Graph Designer and the Report Designer. Click these buttons for context sensitive help on the functionality in question.

Printable (PDF) Documents

Several printable (PDF) documents accompany this version of OD Tool Kit, including a set of tutorials (Getting Started with ODTK), a scripting guide, and documents explaining the mathematical and scientific background of OD Tool Kit. To access these documents, go to the manuals page.