The purpose of this web page is to help Vaisala customers perform a correction for their radiosonde ground receiving systems. The correction applies to the ground receiving system software versions delivered prior to summer 2009. The page includes:
SW correction packages for all versions of radiosonde ground receiving systems
- Documents to assist in MW15, MW12 and MW11 upgrades
- In June 2009 Vaisala detected a software defect in its sounding ground receiving equipment, relating to GPS data quality control
- Due to the defect, the soundings with uncorrected ground receiving systems lack wind information or it is not possible to initiate a sounding with GPS wind finding. PTU soundings are possible by selecting a PTU-only mode (instructions below)
- The problem does not affect soundings with Loran-C radiosondes (such as RS92-KL) or PTU-only radiosondes (such as RS92-K). The problem does not affect soundings with RS80-generation GPS radiosondes (such as RS80-15G)
- In cases of questions, please contact Vaisala helpdesk (email@example.com) or your Vaisala Account Manager
SW correction packages
Please make sure to select the correct SW correction package for your system using the links in the tables below.
The SW correction package for AUTOSONDE, MW31 and MW21 systems is a single .exe file that performs the following functions:
1. It detects the current installation of the DigiCora III SW in the system, and checks the version of the SW
2. It creates a backup copy of the file to be replaced (gpsdcc.dll to gpsdcc.bak)
3. It installs the corrected version of the file, for that particular SW version, to the system (replaces the existing gpsdcc.dll with the corrected one, for that SW version)
The SW correction packages for MW15, MW12 and MW11 systems are specific to the current version of MWG card firmware.
How do I check which version of the SW my system has?
In AUTOSONDE, MW31 and MW21 systems it is not necessary to check the version of the SW before running the installation package, because it will detect your SW version and perform the right correction procedure for it. However, if you want to check the SW version of your sounding system, please check the following Windows registry key:
In MW15, MW12 and MW11 systems please refer to the installation instruction document (link given below).
How do I revert back from the installation?
In AUTOSONDE, MW31 and MW21 systems, uninstall the DigiCORA GPShotFix using the Add/Remove Programs tool of the Windows operating system. Add/Remove Programs tool is typically found in the Control Panel of the operating system. However, we have no reports of any case in which the uninstall was necessary.
Link to SW correction package
3.52.1 and 3.52
Do not install this version to systems which have SW version 3.52.2 or 3.52.3
3.52.3 and 3.52.2
Special correction delivered individually to customers
All known installations of these special SW versions have been corrected.
MW31 and MW21:
The MW22M systems require the correction only in case RS92-SGP sondes are used with it. The defect does not affect the soundings performed with RS92-AM sondes.
Link to SW correction package
3.12 (all systems have this SW version)
Testing complete. The upgrade for MW22M systems is available via
. The customers are contacted separately and individually.
MW15, MW12 and MW11
Installation instructions for MWG2xx Card Firmware GPS Upgrade: M2110034EN-A.pdf
. Notice that upgrading the firmware software requires a PC and a serial cable, such as the one used with METGRAPH software. Appendix A of the installation instruction includes the connection diagrams of the applicable cables. Please contact Vaisala Helpdesk at
if you have problems installing the firmware upgrade or if you need the required cable.
Questions and answers (July 2009)
What is the problem about?
After June 20th 2009, Vaisala DigiCora sounding systems MW11, MW12, MW15, MW21, and MW31, including AUTOSONDE systems, are malfunctioning when used for GPS soundings, unless a SW correction package is installed. Soundings performed with Loran-C radio navigation system or with PTU-only sondes are not affected. Soundings performed with older generation RS80-15G GPS radiosondes are not affected, because the type of GPS processing related to these radiosondes is different.
What is causing the problem?
The problem is caused by a defect in software responsible for GPS data quality control. The defect is related to the recent change of the GPS almanac week from week 512 to 513, and a failure of the software to handle GPS week larger than 512 correctly.
How does the software problem show in uncorrected Vaisala's equipment?
Typically, it is not possible to initiate a sounding with GPS wind type activated [manual sounding systems]. Alternatively, all GPS wind data is missing [AUTOSONDE sounding systems].
Is the problem in the ground system, in the radiosonde, or both?
The problem is in the ground receiving system. The problem is not in the radiosonde and it has no effect on the radiosondes.
Does this affect dropsonde operations?
No. Although dropsonde systems include MWG cards, the software is different and the defect is not in the software of the dropsonde systems.
When was the problem detected?
The problem started on June 21st, 2009, and the first reports came to Vaisala on Monday, June 22nd around 02:00 UTC. The first SW correction packages were published on June 23rd around 10:15 UTC, and the full set of SW correction packages for all versions was published on June 25th, 2009 around 10:00 UTC.
How does the system indicate the problem?
The message received can read e.g. "GPS not synchronized" or when radiosonde is taken outdoors, the message can read e.g. "Warning - insufficient data".
What do the customers need to do?
Please install the SW correction package to your system as soon as possible. You will then be able to continue sounding operations normally.
How can the situation be resolved - temporarily and permanently?
The installation of the software correction package resolves the situation.
In case you need help with the installation of the SW correction package, do no hesitate to contact Vaisala Helpdesk by emailing firstname.lastname@example.org
for installation support.Can the software fix be distributed remotely?
Yes, the software fix is provided remotely through the web at http://www.vaisala.com/ and when necessary, through e-mail.
If receiving an update through the web or by e-mail is not possible for the customer, Vaisala will provide a CD-ROM or DVD-update upon request.