DARTCOM POLAR ORBITER INGESTER RELEASE NOTES (November 29th, 2021) This file documents new features, changes and bug fixes up to the current release of the Dartcom Polar Orbiter Ingester software. The history is listed in reverse chronological order, with the most recent version at the top. If you discover any further bugs or have suggestions for changes or new features, please report them to the following address: bugs@dartcom.co.uk VERSION 5.1i An issue with AHRPT iDAP image outputs not being calibrated if the channel 3A/3B switchover occurred during the pass has been fixed. VERSION 5.1h Support has been added for additional types of downconverter. Layer parameters have been optimised to improve performance and reduce overheads. Optimisations have been made to TCP/IP and UDP/IP data sources to improve performance and reduce overheads. The missing data detection algorithms for HRPT and AHRPT have been improved to eliminate rare occurrences of excess missing lines being inserted. The navigation accuracy of AHRPT images has been significantly improved. The swathe angles for NOAA and Metop satellites have been updated to improve navigation accuracy. Frame synchronisation now times out after 5 seconds if no data is received from a data source. Several Orbit AL-72XX park modes would generate a spurious alarm. This has been fixed. The temperature monitor would occasionally generate a communications alarm. This has been fixed. Overlays on some HRPT and AHRPT images were missing a narrow strip at the top of images. This has been fixed. Redundant previews for ingested HRPT and DMSP data weren't being deleted leading to a build-up of temporary files. This has been fixed. The Microsoft Visual C++ 2019 runtime has been updated to the latest version (14.29.30135.0). Various other minor changes and bug fixes. VERSION 5.0d The path selection window now includes a new network enumerator that uses the Windows Shell API instead of the Windows Networking API which relied on SMB v1 being enabled. Various other minor changes and bug fixes. VERSION 5.0c Support has been added for additional types of receiver, downconverter and rotator. Due to the use of new Windows APIs present only in Windows 8 onwards, Windows 7 is no longer supported. The Microsoft Visual C++ 2019 runtime has been updated to the latest version (14.28.29914.0). The Dartcom USB drivers have been updated for compatibility with Windows 10 version 2009. Various other minor changes and bug fixes. VERSION 4.10b To allow support for additional rotators to be added and their settings accommodated, the Antenna tab has been redesigned slightly. A summary of the rotator settings is now shown, together with a Settings... button that allows the rotator settings to be changed. The park mode can still be changed within the Antenna tab itself. Under certain conditions, parts of the Polar Orbiter Ingester user interface wouldn't always redraw properly. This has been fixed. The Visual Studio 2019 runtime has been updated to the latest version (14.28.29334.0). Various other minor changes and bug fixes. VERSION 4.9g Antarctica was missing from the new default overlays, and also from the globe and image preview overlays, and has been added to all three. If you use the default overlays for outputs, after updating reset your overlay settings to defaults to include the Antarctica overlay. The GSHHG Antarctica overlays had spurious lines where they spanned the 0 degree and 180 degree longitude lines. These have been fixed in the associated Map Overlays Update (December 2020). The "Externally controlled" receiver type couldn't be selected. This has been fixed. Pass swathes spanning the South Pole weren't completely outlined on the globe. This has been fixed. AHRPT (Metop) passes had spurious Reed-Solomon errors in all data packets, though all were corrected. This has been fixed. Various other minor changes and bug fixes. VERSION 4.9c The separate Map Overlays Update must also be installed when upgrading from version 10.7h or older. This provides new, up-to-date, high-resolution overlays created from the GSHHG data set and broken down into coastlines, lakes and lake islands. Image previews will automatically use the new overlays, but to ensure continuity existing iDAP image outputs won't. The quickest way to make existing outputs use the new overlays is to change the default overlays by selecting iDAP image in the outputs tree, then click Settings, then Map overlays. To replace the existing overlays with the new standard set (green coastlines and lake islands, blue lakes, red political boundaries) click Reset to defaults. Alternatively, select appropriate GSHHG overlays to replace your existing World overlays. Map overlays created by this version will have smoother lines with fewer points, improving their appearance and drawing speed. The appearance of the graphical globe displaying details of the next pass, selected pass, sun and ground station has been improved, with new overlays created from the GSHHG data set, and a revised colour scheme. The Calibrate... button in the Antenna tab is now available when the access level is set to Advanced. However the full range of calibration facilities are only available when the access level is set to Engineer. With Advanced access, the rotator calibration can be checked but not altered. If the Default map overlays option was selected for an iDAP image output, the default overlays weren't used. This has been fixed. The overlay selection drop-lists in the Overlay settings windows didn't have vertical scroll bars, and deleting an overlay didn't always work correctly. These issues have been fixed, and the drop-lists are now wider to accommodate longer overlay names. Recompiled using Microsoft Visual Studio 2019 with the latest Windows 10 SDK. Various other minor changes and bug fixes. VERSION 4.8h The current rotator position is now checked in Track or Ingest modes before tracking a pass or updating the park position. If found to be outside the normal range, an alarm is generated and the rotator is automatically reset. In many cases (other than mechanical failure) this provides automatic recovery from that situation, whereas previously manual intervention was needed. The default prediction data file URLs all now use the HTTPS protocol due to security concerns with the FTP protocol. An issue with the first-run default paths being incorrect or empty has been fixed. The Dartcom USB drivers have been updated for compatibility with Windows 10 version 2004. Various other minor changes and bug fixes. VERSION 4.7i An issue with the software housekeeping routines not running under certain circumstances has been fixed. Various other minor changes and bug fixes. VERSION 4.7h The concept of an "ingest device" has been renamed to a "data source" as part of broadening the types of data stream supported. Instead of a data source (formerly ingest device) being chosen directly in the settings tab for each data type (e.g. AHRPT, Terra), the current data source settings are shown in the Data source area, together with a Settings... button that displays the Data source settings window. The button is only available when the access level is set to Advanced or Engineer. Support for TCP/IP data sources (client and server) has been added. Support for UDP/IP data sources (unicast and multicast) has been added. Performing a receiver status check with the Quorum HRD-200B receiver immediately after powering it up no longer fails. To ensure USB devices can be reselected if disconnected or switched off, all serial port and USB ingest device drop-lists are now enabled in Normal access mode. Various other minor changes and bug fixes. VERSION 4.6a The type of ingest device can now be selected, and the Quorum LRD-200B receiver USB interface is now supported for HRPT, AHRPT and DMSP ingest. Various other minor changes and bug fixes. VERSION 4.5b The DMSP-5D2-F14 satellite has been decommissioned and therefore removed from the list in the Satellites tab. Various other minor changes and bug fixes. VERSION 4.4b Ingest time windows for the entire pass schedule can now be specified in the Scheduler tab. These are in addition to any ingest time windows set up for each satellite in the ingester tabs. Passes from a satellite will only be ingested where its time windows overlap with the schedule time windows. Support has been added to the antenna calibration window for the new Dartcom antenna alignment inclinometer used with the Orbit AL-7200 series of gyro-stabilised platforms. This is only normally used by Dartcom engineers when installing the antenna, but is also required if one or both axis encoders are replaced for any reason. A small change has been made to the Motorola Oncore M12+ GPS receiver initialisation sequence to ensure it is in polled mode. This has added about a second to the time required to initially open communications with the GPS receiver. The Dartcom USB drivers have been updated for compatibility with Windows 10 version 1909. A crash problem when closing Polar Orbiter Ingester after data has been output to the NASA RT-STPS software has been fixed. Various other minor changes and bug fixes. VERSION 4.3n CPU usage by Polar Orbiter Ingester while ingesting X-Band EOS data is now significantly lower. FengYun-3D ingest is now fully supported with the Quorum HRD-200B receiver. Your receiver will require firmware updates for it work correctly - please email support@dartcom.co.uk for more information. The Dartcom USB drivers have been updated for compatibility with Windows 10 version 1903. Various other minor changes and bug fixes. VERSION 4.3j The PCI Geomatica, ERDAS IMAGINE, ENVI/IDL and GeoTIFF outputs had not worked correctly since version 4.0 - all the raw and calibrated planes contained the same data. This issue has now been fixed. The ERDAS IMAGINE output did not work if additional data was selected without also selecting calibrated data. This problem has now been fixed. The default set of prediction data files has been updated to use https for the DRL.tle file as FTP access to that file is now blocked by NASA. You will either need to reset your prediction data files to defaults, or edit the URL for DRL.tle and replace ftp with https. The delete icon used in various windows has been changed from a cross to a dustbin. Various other minor changes and bug fixes. VERSION 4.2i A new option has been added to map options that causes the projection to be automatically centred on the current station position. This is intended for moving vessels, so map options "follow" the vessel. It can be switched on or off using the Automatically centre on station tick box in the Map options manager window. It can only be switched on in Easy mapping mode and cannot be used with the Hammer, Miller Cylindrical, Mollweide, Robinson, Sinusoidal or Wagner projections. Colour selectors now have a new look that fully utilises Windows themes. Support for the new COMS LRIT (64kbps) mode in the Quorum LRD-200B and HRD-200B receivers has been added. Your receiver will require a firmware update to enable the new mode - please email support@dartcom.co.uk for more information. Initial support for the new FengYun-3D inverted spectrum mode in the Quorum HRD-200B receiver has been added. Your receiver will require a firmware update to enable the new mode - please email support@dartcom.co.uk for more information. Various other minor changes and bug fixes. VERSION 4.2g Various minor changes and bug fixes. VERSION 4.2e If the GPS type is set to None, the status can now still be exported to a file and the station position entered in the General tab will be exported instead. The recently launched FY-3D and JPSS-2 satellites have been added, including support for the special receiver modes required for them. Receiver firmware upgrades are also required - please contact Dartcom to arrange this. Due to the increase in data rate for FY-3D, the FY-3 X ingester now assumes all of the FY-3 series uses the higher data rate. This may cause slower frame synchronisation after a noise burst with FY-3A to FY-3C. A crash problem with the PCI Geomatica, ERDAS Imagine, ENVI/IDL and GeoTIFF outputs has been fixed. Various other minor changes and bug fixes. VERSION 4.1i The icons in path selection windows now match those in the Windows version on which the software is running. Metop-C has been added to the satellites database, with pre-launch calibration coefficients until the satellite is declared operational and the final coefficients published. The Dartcom USB drivers have been updated for compatibility with Windows 10 version 1809. Various other minor changes. VERSION 4.0f iDAP image outputs now produce the new iDAP file format (see the release notes for iDAP/MacroPro). This has reduced the amount of memory used by Polar Orbiter Ingester while producing these outputs, at the expense of increased use of temporary storage. Multi-plane image files will use about 33% more storage than the old file format. The AHRPT ingester was not deleting some of its temporary files, leading to a build-up over time. This has been fixed. The AHRPT ingester was logging false archiving errors related to previews. This has been fixed. An issue with missing lines being recorded incorrectly in AHRPT raw data files has been fixed. This led to a problem with repairing lines not producing the expected results. Various other minor changes and bug fixes. VERSION 3.6m Support for the Orbit AL-7205 and AL-7207 antenna platforms has been added, with improved reporting of system messages for all AL-7200 series platforms, and in increase in position update frequency for the AL-7205 platform to ensure accurate tracking of X-Band passes. Various other minor changes and bug fixes. VERSION 3.6i Support for the new Dartcom temperature monitor module has been added. This monitors up to 3 temperature probes and can disable tracking if limits are exceeded, to protect the antenna system from damage. A pop-up status window can be shown using the new temperature monitor status icon in the bottom right corner of the main window. This provides detailed status information, current readings and a graph showing the last 24 hours. The General tab has been redesigned so more prediction data files are visible. The default set of prediction data files has also been updated to include those available from Celestrak and NASA, covering all current satellites. To use the default prediction data file set, click Reset to defaults. After doing that we advise checking the prediction data file and satellite name for each satellite in the Satellites tab, reselecting them where necessary. The GPS status has been moved out of the General tab into its own pop-up status window. This can be shown by clicking the GPS status icon in the bottom right corner of the main window. The Scheduler tab has been redesigned to incorporate an Overrides area. This currently allows the temperature monitor to be overridden if it has disabled tracking. Overrides can only be switched on or off at Advanced access level. The Antenna tab has been redesigned to incorporate settings for the new temperature monitor module. They can only be changed at Engineer access level. A pop-up status window has been added showing the prediction data status. This can be shown by clicking the prediction data status icon in the bottom right corner of the main window. The positions and sizes of the main application window and pop-up status windows are now remembered between sessions. The Dartcom USB drivers have been updated to fully support the latest Windows 10 updates. Various other minor changes, bug fixes and enhancements. VERSION 3.4e Various minor changes, bug fixes and enhancements. VERSION 3.3d A JPSS-1 ingester has been added to support the newly launched JPSS-1 satellite. Various other minor changes and bug fixes. VERSION 3.2i Various minor changes, bug fixes and enhancements. VERSION 3.1i The format of iDAP/MacroPro files (.did/.dmd) has changed slightly and the version number has therefore been increased to 24. Please ensure all other Dartcom software is updated to use the same file format version. The supported version is shown in the About window (Help > About). Various other minor changes and bug fixes. VERSION 3.0f Issues with files produced by GeoTIFF outputs not being recognised by some third-party software packages have hopefully been resolved. The format of iDAP/MacroPro files (.did/.dmd/.dfd) has changed slightly and the version number has therefore been increased to 23. Please ensure all other Dartcom software is updated to use the same file format version. The supported version is shown in the About window (Help > About). The Windows SDK has been updated to version 8.1 which supports Windows 7, 8 and 10. Earlier Windows versions (including XP and Vista) are no longer supported. The Dartcom USB drivers have been updated to fully support Windows 10. Third-party libraries have been updated to their latest available versions. A problem with occasional mis-identification of the source satellite for FY3 data that caused knock-on problems with the FY3L0pp processing software has been fixed. Various other minor changes and bug fixes. VERSION 2.4i Problems with overlay misalignment on very large images have been fixed. To correct the overlays on existing images, open them in iDAP, go to Navigation > Overlay Settings... and click OK. This causes the overlays to be redrawn with correct alignment. Various other minor changes and bug fixes. VERSION 2.4h In automatic scheduling mode passes were not being removed from the on-screen schedule after tracking or ingest. This has been fixed. Various other minor changes and bug fixes. VERSION 2.4f Changes to the ingester settings were still not always taking effect if the PC time had changed between clicking Apply Settings and pass ingest starting - this has been fixed again. The FY3L0pp, NOAA level 1B, EPS level 0 and HRPT raw outputs were only producing the first output for each pass if multiple outputs had been set up - this has been fixed. Various other minor changes and bug fixes. VERSION 2.4b The FY-3 L-Band ingester now uses the built-in LRD-200B receiver USB interface module instead of an AHRPT/LRD USB interface module in the receiver rack. The .exe file is now digitally signed with Dartcom's code signing certificate. VERSION 2.3c The receiver mode can now be configured for each satellite using the Mode box in the Satellites tab. The default settings for existing users will be correct for all satellites except Feng Yun 3C L which requires a special mode due to the non-standard data rate used on the L-Band service on that satellite. Users with an LRD-200B receiver will also need a firmware upgrade to enable the new mode in their receiver. The CHRPT ingester tab has been removed due to the last remaining CHRPT satellite, Feng Yun 1D, being declared non-operational (source: http://www.wmo-sat.info/oscar/satellites/view/104). NOAA 16 has also recently been decommissioned (source: http://www.wmo-sat.info/oscar/satellites/view/338). Therefore both it and Feng Yun 1D have been removed from the default satellites list created by fresh installs. However existing users will need to manually remove both satellites from the list in the Satellites tab. The extension used for data files produced by the FY3L0pp outputs has been changed from '.vcdu' to '.org' to resolve a compatibility issue with the FY3L0pp software. Various other minor changes and bug fixes. VERSION 2.2c In manual scheduling mode, changes made to the schedule are now preserved if Polar Orbiter Ingester is restarted for any reason. Support has been added for controlling the feed polarisation with the Dartcom XDC downconverter. During a group of overlapping passes, the correct next pass was not always shown on the globe if the enabled pass was not the one which ended last - this has been fixed. Various other minor changes and bug fixes. VERSION 2.1n To fix an issue with map overlays not aligning with reference points in iDAP at high zoom levels, overlays are now created at a slightly higher resolution, requiring slightly more disk space as a result. VERSION 2.1m An issue with certain overhead passes not being tracked correctly with the MAD Turbo rotator has been fixed. ASCAT data was incorrectly reporting packet sequence errors in the AHRPT detailed status window - this has been fixed. Changes to the ingester settings were not taking effect if the PC time had changed between clicking Apply Settings and pass ingest starting - this has been fixed. Changes have been made to the rotator calibration window to improve its functionality. Various other minor changes and bug fixes. VERSION 2.1h The format of iDAP/MacroPro files (.did/.dmd/.dfd) has changed slightly and the version number has therefore been increased to 22. Please ensure all other Dartcom software is updated to use the same file format version. The supported version is shown in the About window (Help > About). The online help is now fully up-to-date. More than one RT-STPS output can now be set up, so a single ingester can feed multiple processing systems if required. The scheduler now handles groups of overlapping passes more intelligently, analysing them to find non-overlapping sub-groups, and enabling the appropriate pass in each sub-group according to the scheduler settings. This results in more passes being included in the schedule. Previously only one pass in a group of overlapping passes would have been enabled, even if there were other passes in the group that did not overlap with it. The reliability and performance of the DMSP ingester has been improved. Missing lines in DMSP images are now shown in black on previews rather than the software attempting to repair them. This makes it clearer where the missing lines are. However they can still be repaired by outputs. DMSP images now navigate correctly - previously the end of a pass may not have been navigated. Night-time DMSP images now have the correct channel assignments - previously the infra-red and visible channels were transposed in some cases. DMSP images are now calibrated correctly - previously the raw read-outs for infra-red channels were inverted in some cases, causing incorrect temperature read-outs. Various other minor changes and bug fixes. VERSION 2.0r Support has been added for ingesting raw X-band data from Terra, Aqua, SUOMI NPP and Feng Yun 3A/B/C satellites. To allow this, the Quorum HRD-200B receiver and new Dartcom XDC programmable X-band downconverter are now supported. File and TCP/IP socket outputs have been added for raw X-band data allowing it to be fed into processing software such as RT-STPS and FY3L0pp for generating level 1 data and products. Support has been added for ingesting raw L-band data from Feng Yun 3A/B/C satellites, together with a file output allowing it to be fed into the FY3L0pp processing software for generating level 1 data and products. The Dartcom USB interface drivers and associated ingest subsystems have been completely redeveloped and are now compatible with 64-bit versions of Windows (as well as 32-bit). Reed-Solomon decoding is now performed in its own separate layer, ensuring continuous, reliable ingest even during noisy data requiring significant error correction. The "Receiver" area in each ingester settings tab has been altered to just display the current settings. To edit them, click the "Settings..." button (requires "Advanced" or "Engineer" access). The downconverter can now be selected separately for each ingester rather than globally in the "Antenna" tab. This is to allow X-band and L-band data to be ingested on the same PC. The previous global downconverter setting will be set as the default for all ingesters (where supported) if upgrading from a previous version, but please check it is selected correctly in each ingester settings tab after upgrading. A "Track passes" tick box has been added to each ingester settings tab, allowing passes to be tracked but without ingesting data. This is to allow a distributed ingesting setup with multiple instances of Polar Orbiter Ingester running on different machines (or virtual machines). The GPS receiver time synchronisation has been greatly improved and should now keep the PC clock within 20 milliseconds of the correct time. This will produce a significant improvement in rotator tracking accuracy. The rotator tracking accuracy has been further improved on the Winter 1020, Winter 1037, MAD XPA and MAD Turbo rotators through more frequent position updates. The "Invert" button in the "Antenna" tab now functions as a switch, so all positions commanded using the sliders in the "Manual control" area and the "Track Sun" and "Park" modes will be inverted if the "Invert" button is switched on. Many other minor changes and bug fixes. VERSION 1.9e The overhead pass tracking algorithm has been rewritten to greatly improve pointing accuracy, especially within the second half of passes. Support has been added for the new MAD Turbo rotator and Quorum LRD-200B receiver. The pass schedule can now be copied to the clipboard in text format using the small icon above the scroll bar. The SeaWiFS ingester has been removed due to the complete failure of the SeaStar satellite with no scheduled replacement. We recommend you delete SeaStar from the list in the "Satellites" tab. A problem with loss of DMSP reception during significant periods without valid data has been fixed. The prediction data was updated every time the software was started even if automatic updating was switched off - this has been fixed. The pass schedule was calculated twice every time the software was started - this has been fixed so it is only calculated once. A problem with the "Calibration Editor" window following import and export has been fixed so it now correctly reports the planes imported or exported. Various other minor changes and bug fixes. VERSION 1.8m The EPS level 0 exporter has been revised to output a single file for each product type, as required by the AAPP processing package. Support has also been added for the Multi-Mission Admin Message and various issues have been fixed. A problem where communications were sometimes lost with the Orbit AL-72XX antenna platform controller using TCP/IP has been fixed. A crash problem with the "Archive Browser" window when a new pass was archived while the pass list was being refreshed has been fixed. The GeoTIFF output was not archiving files even if archiving was switched on. This has been fixed. A problem with the new frame synchroniser which caused occasional missing or corrupted lines in good data on HRPT/CHRPT/SeaWiFS images has been fixed. A problem with single plane AHRPT iDAP image outputs which caused incorrect grey values has been fixed. Various other minor changes and bug fixes. VERSION 1.8b The frame synchroniser has been completely rewritten to improve its tolerance of noisy or weak satellite signals, resulting in fewer missing/corrupted lines or segments, faster resynchronisation following bursts of noise and reduced processor usage overall. The online help is now fully up-to-date. GOME-2 data from Metop will now be ingested correctly. Various other minor changes and bug fixes. VERSION 1.7k AHRPT (Metop) data can now be output in EPS Level 0 format for use with the AAPP processing package and other third-party software. A licence key is required - please contact Dartcom for more details. The list of outputs for each data type is now sorted differently, with the most commonly used ones at the top for convenience. Support has been added for the new Dartcom MAD XPA rotator now supplied as standard with 1.2m and 1.5m land-based L-Band Polar Orbiter systems. The GPS receiver type can now be set to "None" to suppress GPS update errors if no GPS receiver is connected to the system. AHRPT (Metop) data will now have improved navigation accuracy towards the edges of the image. A small error in the headers produced by the ERDAS outputs has been fixed - the pixel resolution was in kilometres instead of metres. GPS updates erroneously continued to occur in Manual mode. This has been fixed and they will now only occur in Track or Ingest modes. Clicking the "Refresh Files" button in the "Satellites" tab with a satellite selected would cause the selected TBUS file to change to the SGP4 file and the TBUS name to be blank. The same thing would also happen if a satellite was selected during a prediction data update. This has now been fixed. Various other minor changes and bug fixes. VERSION 1.6e A problem with the Other raw format output where the resulting files were sometimes missing data from the end of the pass has been fixed. Various other minor changes and bug fixes. VERSION 1.6c Single plane images created by the iDAP image output now have the full 256 greyscales. Previously they were quantized to 128 greyscales because the other 128 colours in the palette were reserved for the Processing > Formula palette function in iDAP. However this has been rewritten to remove that requirement. Support for the new MAD XPA rotator has been added. The allowable frequency range for DMSP satellites has been extended to support the new frequencies. The demodulator status for the Quorum MetCom/LRD-100 receivers was shown as "unknown" if the status was FR (frames detected). This has been fixed. Various other minor changes and bug fixes. VERSION 1.4e: Problems with incorrect navigation and output of northbound AHRPT images have been fixed. Various other minor changes and bug fixes. Recompiled using Microsoft Visual Studio 2010. VERSION 1.3h: A GeoTIFF output has been added. A licence key is required to use it - please contact Dartcom for more details. The drivers for Dartcom USB HRPT/CHRPT/SeaWiFS, AHRPT/LRD and DMSP interfaces have been updated to resolve occasional problems with data buffer overflows on Windows 7. Various other minor changes and bug fixes. VERSION 1.2b: PCI Geomatica, ERDAS IMAGINE and ENVI/IDL outputs have been added. Licence keys are required to use them - please contact Dartcom for more details. Problems with AHRPT iDAP image outputs being generated twice and archived outputs being overwritten have been fixed. The automatically calculated 10-bit to 8-bit conversion limits for AHRPT iDAP image outputs no longer clip the top and bottom data values. Various other minor changes and bug fixes. VERSION 1.1t: Map overlays with dotted or dashed lines are now drawn correctly. The mouse scroll wheel can now be used to scroll image previews. Windows XP users should check they have installed Service Pack 3 (SP3) as resource leaks in SP2 can cause problems when running software for long periods of time. Other minor changes and bug fixes. VERSION 1.1n: The NOAA level 1B output ignored the byte order and packing settings and always produced little-endian unpacked data - this has been fixed. Other minor changes and bug fixes. VERSION 1.1k: Minor changes and bug fixes. VERSION 1.1g: Fixed a resource leak which could result in the software crashing after an extended period of continuous running. VERSION 1.1f: Minor changes and bug fixes. VERSION 1.1c: Major and minor grid lines are now supported in the overlay settings window, plus different line styles and widths. The Dartcom synthesised receiver is now supported. Other minor changes and bug fixes. VERSION 1.0b: Initial release.