YaDDNet Data accuracy, again...

John Pumford-Green

Hello all,

I've had to set up a method of deleting the loggings being sent by contributors who can not set up their Yadd and RX correctly and are sending DSC data bearing the wrong RX Frequency.

Some people make an honest mistake, and once corrected I'm happy to take no further action, but there are a few people who consistently send data that is wrong.

I now have a system running on YaDDNet that looks for all NEW (within the last 24 hours) loggings of a list of RX_IDs and deletes them. The list of RX_IDs is created manually by myself, when I notice obvious errors.

The auto-deletion of data occurs every 30 minutes. If I care to spend the time, this 30 minutes gives me a window of opportunity to decide if a contributor is no longer sending bogus information, and if so I can remove it from the list.

As I write this email the list is:


You can see the list actively being used to auto-delete loggings here:


and the number of deletions made for these RX_IDs:


If you see your own RX_ID on the list, and you believe that you are sending trustworthy data then please let me know by email:


and I'll check, and if appropriate I'll remove you from the list.

These links are available from the yaddnet home page, too:


scroll down to the "Additional Information" area of the index page.

I'd rather be over zealous at deleting data than to let erroneous loggings remain in the database...

I spot "dubious" reports from a SQL query via this page:


which shows any loggings that are for coast stations on "unusual" frequencies.

The SQL query used is:

$result = mysqli_query($con, "select * from newlog where DATETIME>date_sub(now(), interval 3 day) and ( (RX_FREQ > 2189.5 and RX_FREQ < 30000.0 and FROM_TYPE = 'COAST' and ( FROM_MID = 244 or RAW_FROM_MMSI = '002191000' or FROM_MID = 247 or FROM_MID = 261 or FROM_MID = 232 or FROM_MID = 250 or FROM_MID = 211 or FROM_MID = 227 or FROM_MID = 205) and RAW_FROM_MMSI != '002320204' and RAW_FROM_MMSI != '219015591' ) or (RX_FREQ = '2187.5' and FROM_TYPE = 'COAST' and (FROM_MID = 366 or FROM_MID = 503)) or ( RX_FREQ = '2177.0' and FROM_TYPE = 'COAST' and (FROM_MID != '257' and FROM_MID != '224' and FROM_MID != '251' and FROM_MID != '235' and FROM_MID != '237' and FROM_MID != '276' and FROM_MID != '205' and FROM_MID != '228' and FROM_MID != '258' and FROM_MID != '219' ) )) order by DATETIME desc");

It attempts to spot European coast stations being reported on HF, American and Australian Coast Stations reported on MF and Coast Stations outside of the "normal" MIDs using 2177.0.

This tends to catch situations where a contributor is mis-reporting. It doesn't catch all their "duff" data, but gives a clue that something is wrong....

I'm tiring of the effort needed to keep things "clean", and might decide soon that YaDDNet has run its course, and is no longer a viable project...





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