Problem stations - Revision history

Lissy at 19:10, 13 August 2008

2008-08-13T19:10:02Z

Lissy: /* LOGC */

2008-02-29T23:34:49Z

‎LOGC

Lissy at 23:31, 29 February 2008

2008-02-29T23:31:40Z

Lissy: /* del_qm */

2008-02-29T23:25:24Z

‎del_qm

Lissy: /* del_qm */

2008-02-05T22:39:42Z

‎del_qm

Lissy: /* del_qm */

2008-02-05T22:39:22Z

‎del_qm

Lissy: /* del_qm */

2008-02-05T22:28:45Z

‎del_qm

Lissy: /* del_qm */

2008-02-05T21:08:22Z

‎del_qm

Lissy: /* more commands */

2008-02-05T20:58:21Z

‎more commands

Lissy: /* del_pt */

2007-12-09T01:13:17Z

‎del_pt

@@ Line 69: / Line 69: @@
    cd $ANALYSIS/wwww/flt
    pppclean yymmmddxxxx____??
 === assignments of problems ===

@@ Line 283: / Line 283: @@
   (and so on)
-==== LOGC ====
+==== IRKJ - good example of odd receiver behavior - oscillating psuedorange residuals ====
-The psuedorange residuals for all satellites follow a strange pattern, oscillating
+The psuedorange residuals for all satellites follow a strange pattern, between -200 and +600. Residuals are similar for all satellites. What is happening here, I think, is some instability of the receiver clock or of something similar to that. Something like this happened with the site SHAO a few years ago, except with larger magnitude. The phase data is very clean.
- between -200 and +600. Residuals are similar for all satellites. What is happening here,
- I think, is some instability of the receiver clock or of something similar to that.
+There are only two things you can do in this case. One is to leave the data alone. Don't try to delete the data point by point, and don't try to delete just the pseudorange data for everything. Instead, you can add this to a list we keep of days where ALL pseudorange data should be ignored. Then you don't delete anything -- the data file stays the same but we only use the phase.
- Something like this happened with the site SHAO a few years ago, except with larger
- magnitude. The phase data is very clean.
-−
- There are only two things you can do in this case. One is to leave the data alone. Don't
- try to delete the data point by point, and don't try to delete just the pseudorange data
- for everything. Instead, you can add this to a list we keep of days where ALL pseudorange
- data should be ignored. Then you don't delete anything -- the data file stays the same
- but we only use the phase.
-−
   vi /gipsy/info/Problem.bad_pcode
   (go to the end of the file)
@@ Line 301: / Line 293: @@
 aug16 IRKJ
 ==== LOGC ====

← Older revision		Revision as of 23:31, 29 February 2008
Line 282:		Line 282:

	(and so on)		(and so on)
		+
		+	==== LOGC ====
		+	The psuedorange residuals for all satellites follow a strange pattern, oscillating
		+	between -200 and +600. Residuals are similar for all satellites. What is happening here,
		+	I think, is some instability of the receiver clock or of something similar to that.
		+	Something like this happened with the site SHAO a few years ago, except with larger
		+	magnitude. The phase data is very clean.
		+
		+	There are only two things you can do in this case. One is to leave the data alone. Don't
		+	try to delete the data point by point, and don't try to delete just the pseudorange data
		+	for everything. Instead, you can add this to a list we keep of days where ALL pseudorange
		+	data should be ignored. Then you don't delete anything -- the data file stays the same
		+	but we only use the phase.
		+
		+	vi /gipsy/info/Problem.bad_pcode
		+	(go to the end of the file)
		+	add a line that reads
		+
		+	07aug16 IRKJ
		+
		+	That's it. In all future runs, the pseudorange will be ignored. There are many lines in
		+	this file -- unfortunately most of them are from data where some earlier version of
		+	automatic cleaning flagged the pseudorange as bad, even though in reality it was just a
		+	case of some points needing to be deleted.

@@ Line 44: / Line 44: @@
 ==== del_qm ====
-To delete bad (pseudorange and/ or phase) data you can use the
+To delete bad data you can use the
     del_qm
-command. The -d(110/120) option controls the data typ.
+command.
 You might need to start with the original .qm file, because autoclean will have messed it up.
@@ Line 56: / Line 56: @@
    gunzip *ddxxxx*
    mv yymmmddxxxx____??.qm tmp.qm
-   del_qm -i tmp.qm -o yymmmddxxxx____??.qm -g XXXX -d??? -t1_char "DD-MMM-YYYY HH:MM" -t2_char "DD-MMM-YYYY HH:MM"
+   del_qm -i tmp.qm -o yymmmddxxxx____??.qm -g XXXX -t1_char "DD-MMM-YYYY HH:MM" -t2_char "DD-MMM-YYYY HH:MM"
-Check out del_qm -h for more information/options on the command.
+Check out del_qm -h for more information/options on the command. The station and satellite specifications for del_qm are "OR" operations, not "AND" operations. This is one reason why you have to be really careful about using it.
 Set the CAMP variable (if not set):

@@ Line 56: / Line 56: @@
    gunzip *ddxxxx*
    mv yymmmddxxxx____??.qm tmp.qm
-   del_qm -i tmp.qm -o yymmmddxxxx____??.qm -g XXXX -d??? -t1_char "DD-MMM-YYYY HH:MM"
+   del_qm -i tmp.qm -o yymmmddxxxx____??.qm -g XXXX -d??? -t1_char "DD-MMM-YYYY HH:MM" -t2_char "DD-MMM-YYYY HH:MM"
- -t2_char "DD-MMM-YYYY HH:MM"
 Check out del_qm -h for more information/options on the command.

@@ Line 42: / Line 42: @@
   pppclean 07oct08gmas____u0
 It is perfectly OK to do this, because this is what autoclean would have done if it had  not been messed up by a few bad points. But if there are small cycle slips or a few outliers left, pppclean will not find them (it uses a 10 cm tolerance for jumps in the residuals).
 === assignments of problems ===

@@ Line 7: / Line 7: @@
 === more commands ===
 ==== del_pt ====
- If only a few points have bad pseudorange you can use
+If only a few points have bad pseudorange you can use
   del_pt
 to delete those points. Because there are so few of them I (Jeff) think it is better to remove both phase and pseudorange data for these points, as opposed to removing all pseudorange data for GPS37 using del_pcode_arc. Also,  in my experience when there is a few points like this, often the phase data are bad also. So I would go back to the qm directory and use del_pt by hand to remove the points.