[IGSMAIL-0736] Report of a Turbo Rogue Receiver Problem

[Miranda]

******************************************************************************
IGS Electronic Mail      Wed Oct  5  6:25:37 PDT 1994      Message Number 0736
******************************************************************************

Author: Miranda Chin/CIGNET
Subject: Report of a Turbo Rogue Receiver Problem

Subject: Report of a Turbo Rogue (TR) Receiver Problem 

Station: Richmond, FL     Receiver Serial #: T308        Firmware Version: 2.8.32.1

Description
-----------
Jan Kouba notified CIGNET that the pseudoranges went bad after he analyzed the data using 
the point positioning software, DCRAP. However, this problem could not be detected by using the 
pseudorange_phase combination. CIGNET re-examined the data and found the problem started 
on Sept. 11, around 03:00 UTC.  


Actions Taken
-------------

Date /Time               Description       
----------------------   --------------------------------------------------------------------- 
Sept. 22, '94            Action by CIGNET: warmbooted the receiver by issuing a 'bang' command. 
                         Report by Jan: no change of the pseudorange data quality.
                         
Sept. 28, '94            Action: disabled/enabled all channels.
                         Report: no improvement to the pseudoranges.
                         
Sept. 30, '94            Action: powered off the receiver; waited a few minutes before power it 
                                 on again.
                         Report: improved pseudoranges.

Oct. 5, '94              Report: Jan re-confirmed that the data quality is excellent again by
                                 examining global solutions.
                         

Below are outputs from DCRAP. 'Table I' shows the error of computed point positioning is about
30 meters from Sept. 19's data; and, 'Table II' shows a normal offset from the initial position 
on Oct. 1's data.


Table I.   
--------------------------------------------------------------------------------

 Station:         RICHMOND_RCM5                           Date     : 19/ 9/1994
 -------------------------------------------------------------------------------
               POSITIONING RESULTS - 2873 FIXES WITH GDOP < 10
   X (m.)       Y (m.)       Z (m.)      LATITUDE(dms) LONGITUDE(dms) HEIGHT(m.)
 -------------------------------------------------------------------------------
INITIAL   
   961336.000 -5674079.200  2740539.700   25 36 49.667  -80 23  2.137   -8.985


MEAN      
   961386.276 -5674064.347  2740518.245   25 36 49.126  -80 23   .272  -23.893
+/-    93.079+/-   209.780+/-   124.991


DIFFERENCE
       50.276       14.853      -21.455    0  0   .541    0  0  1.866  -14.907
 -------------------------------------------------------------------------------
               RECEIVER CLOCK PARAMETERS FROM  2873 ESTIMATES
          TIME       OFFSET          S.D. OFFSET     DRIFT         S.D. DRIFT
 -------------------------------------------------------------------------------
RICHM    86400.0     877.9 m    +/-      5.0     -90.5 m/day     +/-    8.6
       0: 0:  .0    2928.5 nsec +/-     16.6    -301.7 nsec/day  +/-   28.7
 -------------------------------------------------------------------------------


Table II.
 -------------------------------------------------------------------------------
       Differential Corrections to Range And Position (DCRAP-  25/03/93)
 -------------------------------------------------------------------------------
 File   : screen/rcm5.rnx                                 Data Rate:    30 sec.
 Station:         RICHMOND_RCM5                           Date     :  1/10/1994
 -------------------------------------------------------------------------------
               POSITIONING RESULTS - 2880 FIXES WITH GDOP < 10
   X (m.)       Y (m.)       Z (m.)      LATITUDE(dms) LONGITUDE(dms) HEIGHT(m.)
 -------------------------------------------------------------------------------
INITIAL   
   961336.000 -5674079.200  2740539.700   25 36 49.667  -80 23  2.137   -8.985


MEAN      
   961336.198 -5674079.590  2740541.834   25 36 49.723  -80 23  2.133   -7.687
+/-    18.270+/-    36.834+/-    20.656


DIFFERENCE
         .198        -.390        2.134    0  0   .057    0  0   .005    1.299
 -------------------------------------------------------------------------------
               RECEIVER CLOCK PARAMETERS FROM  2880 ESTIMATES
          TIME       OFFSET          S.D. OFFSET     DRIFT         S.D. DRIFT
 -------------------------------------------------------------------------------
RICHM   518400.0    -143.4 m    +/-       .9      12.7 m/day     +/-    1.6
       0: 0:  .0    -478.4 nsec +/-      3.2      42.3 nsec/day  +/-    5.5
 -------------------------------------------------------------------------------
                          

[Mailed From: Miranda Chin <miranda at gracie.grdl.noaa.gov>]