Mapping and GIS Solutions Community

Hello.

The client has an old device - a GPS-3903 Receiver.
The problem is that the date is displayed incorrectly - specifically, August 24, 2006, constantly.
Please note the number of weeks - 1372. As far as I understand, the number of weeks should not exceed 1023 (1024).

This is not a Trimble product.

Thanks for the reply.

I might be mistaken.
But there is a sticker like that on the device.

Most likely, the situation looks like this.

The Trimble GPS 3903 is an OEM (Original Equipment Manufacturer) module. This means that Trimble manufactured the board and antenna specifically for another manufacturer (in this case, Videotek, now Imagine Communications) to integrate into their end device.

Trimble considers only those devices sold directly to users under its own brand as its own products. Support for OEM solutions is typically contractually provided by the vendor that sold the end device (Videotek).

The problem is related to the GPS Week Number Rollover (incorrect date), a common issue with older 12-channel Trimble modules of that era, and it's extremely difficult to resolve without a firmware update from the end-equipment manufacturer (Videotek).

And in this situation, you likely won't be able to help.

You can get valid dates out of that GPS "manually" - just add 1024 to the week number.  This adds about 19.6 years to the date, which takes you to about December 2025.

The problem is that the firmware on your receiver is old so it only makes allowance for the first GPS Week Number Rollover (WNRO).  The GPS firmware adds 1024 to the week number (0 to 1023) coming from the satellites which gives week number 1024 to 2047 corresponding to 1999 to 2019.  From the second WNRO, GPS firmware would need to add 2048 to the number coming out of the receiver, to give dates from 2019 to 2039.

The GPS position should be valid - that's my experience with older receivers which don't handle the second WNRO.