Date: Mon, 28 Apr 2003 11:15:55 -0700 From: Pascal Willis To: jean-paul.berthias@cnes.fr Cc: Alfred Piuzzi , Carey Noll , Vincent Patrick , Martine Feissel , Sabine HOURY , "John C. Ries" , Nikita Zelensky , Bruce J Haines Subject: duplicated DORIS/JASON data Hello Jean-Paul, I understand you point and your reasons are valid most of the time,specially for ENVISAT/DORIS data. However, there are still some other problems, like for cycle ja1data040.001.Z data are effectively duplicated : JASON13935KIUB 03 40 6351869821112 70000003-5543068196 947268 58 300 -671 43085181 1196 JASON13935KIUB 03 40 6351869821112 70000003-5543068196 947268 58 300 -671 43085181 1196 the channel is 1 (cut -c 90-90) for both measurements There are 87 measurements like that on that specific day (03FEB09) Best regards Pascal >Hello Pascal, > >In your mail you talk about duplicated data. However, this is not >the case: one >measurement has been performed on channel 1, the other one on >channel 2. Most of >the time, when tracking the same beacon, both channels give the same >result, and >we indicate this by using 3 as channel indicator in the file. >However, there are >times when the two channels do not give the same result. Often this can be >linked to the fact that one of them at least is in error, and we have many >filters to remove those data. > >But there are also cases when we cannot discriminate between the >measurements of >the two channels. In this case they both end up on the delivery file. This is >normal, as both measurements are valid in our sense. > >The fact that you see it more on ENVISAT is certainly related to the screening >procedure which is not as extensive for this type of receiver. The filters on >simultaneous but different measurements were introduced after the >"problem" was >discovered on Jason, and they might not work as well on ENVISAT which is a >receiver of a different technology. We will look into this. > >Jean-Paul -- Pascal Willis Jet Propulsion Laboratory, MS 238-646 Ph : 1-818-393-4748 4800 Oak Grove Drive FAX: 1-818-393-4965 Pasadena CA 91109 Em : Pascal.R.Willis@jpl.nasa.gov