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CRD Format Errata

 

Date: 21 Dec 2017
Version 1.01c1 of the CRD source code is now available on the ILRS web site. The only change is a modification to crd_to_merit.c for an error handling day of year for normal points.

Date: 18 May 2015
Version: 1.01c of the CRD source code is now available on the ILRS web site.This is a cleanup of all the errata entries since version 1.01b.

Issue #: 2015-01

Date: 15 May 2015
Component: sample source code
Version: 1.01b
Routines: crd_conv_slr_c/crd_to_merit.c

Problem: In the case of the starting date in the header being late in one day, but the data records starting early in the next day, the day of year in the Merit II file is wrong.
Change: For record types 10, 11, and 20, use existing mechanism for testing for day roll-over to include a check between header and data record second of day.



Issue #: 2012-02

Date: 22 Jun 2012
Component: sample source code
Version: 1.01b
Routines: crd_chk_c/crd_chk.c

Problem: Program does not make use of return status to indocate data failure. Program does not detect when there are too few end of data records.
Change: Add a "fail" code to provide non-zero return value when program fails due to an error. Also, detect when there are fewer h8 records than h1 or h2 records.



Date: 23 Feb 2012
Version: 1.01b of the CRD source code is now available on the ILRS web site. This is a cleanup of all the errata entries since version 1.01.

Issue #: 2012-01

Date: 02 Feb 2012
Component: sample source code
Version: 1.01b
Routines:

crd_conv_slr_c/read_cstg.c
crd_conv_slr_c/read_merit.c
crd_conv_llr_c/cllr_to_crd.c

Problem: With some compilers versions, there is round off error in seconds of day read from the legacy formats. For cllr_to_crd.c, this is also true for time of flight.
Change: Change all instances of "1.e7" in second of day calculations to "(long double)1.e7". In cllr_to_crd.c, also change "1.e13" to "(long double)1.e13" in time of flight computations.



Issue #: 2011-03

Date: 02 Mar 2011
Component: sample source code
Version: 1.01b
Routines:

crd_conv_slr_c/cstg_to_crd.c
crd_conv_slr_c/read_cstg.c
crd_conv_slr_c/read_merit.c
crd_split_c/merge_crd_daily.c

Problem: The type of getifield returned value is long, but some variables used in the call to getifield are type int, resulting in problems with some compilers.
Change: Changed the type of data_release and syear in crd_conv_clr_c programs and ss, yy, ddd, hhmm, year, mon, day and sic in crd_split/merge_crd_daily.c to long.

Issue #: 2011-02

Date: 02 Mar 2011
Component: sample source code
Version: 1.01b
Routine: crd_conv_slr_c/cstg_to_crd.c
Problem 1:Cannot distinguish native CRD files from those converted from legacy files run through this converter.
Change 1: Add comment to converted file to distinguish from native CRD creation.

NOTE: User should change "site" to reflect their site or organization.

Problem 2:Type of argument to calls to time and gmtime should be time_t but were long.
Change 2: Changed the type of the argument (lclock) to time_t.

Issue #: 2011-01

Date: 25 Jan 2011
Component: sample source code
Version: 1.01b
Routine: crd_chk_c/crd_chk.c
Problem: Previous change for detecting issues with satellite identification printed output at the end of the program run, obscuring the source of the problem. Also, program checked for strict time sequence, regardless of data record type. However, meteorological and differnt data records need only to be in sequence within their record type.
Change: Print identification errors with the other errors from that pass. Check for time out-of-sequence only within each record type. Also, remove/change records in targets.dat having "0" for cospar/ilrs ID. See the following files on the ILRS web site:

crd_chk.c_v1.01b
targets.dat

Issue #: 2010-03

Date:09 Nov 2010
Component: sample source code
Version: 1.01a
Routine:crd_chk_c/crd_chk.c
Problem: Program does not check that target ILRS ID, NORAD ID, SIC, name, and target type agree. This has shown up when stations use non-standard target names on the H3 record.
Change: Apply the difference file to crd_chk.c (v1.01). Add the file targets.dat to the execution directory.

Note: If the diff file below is too difficult to use, please email ricklefs@csr.utexas.edu for the full source code of the new version.

Issue #: 2010-03

Date:09 Nov 2010
Component: sample source code
Version: 1.01a
Routine:crd_chk_c/crd_chk.c
Problem: Program does not check that target ILRS ID, NORAD ID, SIC, name, and target type agree. This has shown up when stations use non-standard target names on the H3 record.
Change: Apply the difference file to crd_chk.c (v1.01). Add the file targets.dat to the execution directory.

Note: If the diff file below is too difficult to use, please email ricklefs@csr.utexas.edu for the full source code of the new version.

Issue #: 2010-02

Date:29 July 2010
Component: sample source code
Version: 1.01 (and 1.00)
Routine:crd_chk_c/crd_chk.c
Problem: Crd_chk disallows a "-1" as the value for the rms of the system delay. There are some instances where this value does not apply, and "-1" should be allowed. In addition, checks of the skew, kurtosis, and peak-mean are absent from the program.
Change: Crd_chk.c line 733 should be changed from 

 if (d40.cal_rms < 0 || d40.cal_rms > 1.e8)

to

 if (d40.cal_rms < -1 || d40.cal_rms > 1.e8)

Missing checks will be added to the next release.

Issue #: 2010-01

Date: 09 April 2010
Component: sample source code
Version: 1.01 (and 1.00)
Routine: common_c/write_crd.c
Problem: The write_11 (normal point record) routine writes only 7 significant digits in the seconds of day field. For consistency with other c and FORTRAN routines, this routine should write 12 significant digits.
Change: Replace line 172

 "11 %.7Lf %.12Lf %-s %d %.1f %d %.1f %.3f %.3f %.1f %.1f %d\n",

with

 "11 %.12Lf %.12Lf %-s %d %.1f %d %.1f %.3f %.3f %.1f %.1f %d\n",

Note: Stations are not requred to write 12 significant digits if the ranging system performance does not warrant this accuracy. Please see the CRD format manual for more information.

Date: 29 October 2009

Version 1.01 of the CRD manual and source code are now available on the ILRS website. Errata below have been rolled into the new version, and there are other corrections and clarifications to the manual. There have been no format changes in version 1.01, in the sense that there are no new additional records or fields, nor have fields been moved or resized.

Issue #: 2009-13

Date: 10 October 2009
Component: manual
Version: 1.00
Section: 3 Data Records, and others
Problem: Analysts asked that the chronological ordering of records be clarified.
Change: Replace the paragraph on order of records with the following. Changes were made in several other places in the manual.
"Data records of the same type must be in chronological order. In other words, all normal point records must be in chronological order; all meteorological records must be in chronological order, etc. Meteorological records, for instance, may be either interleaved with the normal point records or kept together. Times assigned to the calibration ("40") and session ("50") records are at the discretion of the station, although if there are multiple calibration records in a pass, the times should be representative of the time for which they are applicable."

Issue #: 2009-12

Date: 10 October 2009
Component: manual
Version: 1.00
Section: 1.2.2 Notes section for station (H2) header record
Problem: It was discovered that the analysts can not handle any Station Epoch Time Scale values except 3, 4, and 7 without throwing out the data.
Change: Replace paragraph regarding "station epoch time scale": "Currently, values of the Station Epoch Time Scale other than 3, 4, and 7 will not be understood by the SLR data analysts, and data including them will usually be discarded. Since time scales do evolve, and some experiments require higher accuracies than are available with the current techniques, it was necessary to include the possibility of new values (10-99) that did not conflict with current or obsolete historical values. If you believe there is a compelling reason to use another value (e.g. 10 or above) you must propose the new value and explain the reasons to the ILRS Analysis Working Group and the ILRS Data Formats and Procedures Working Group. If they grant approval, you may use the new value, and it will be documented in this manual."

Issue #: 2009-11

Date: 18 August 2009
Component: sample source code
Version: 1.00
Routine: crd_to_merit.c
crd_to_cstg_np.c
crd_to_cstg_ql.c

These programs have had substantial changes to:

  1. accumulate and interpolate meteorological and point angle data, to handle CRD data files in which these record types are sent as blocks with the file.
  2. handle change of day in the middle of a pass (crd_to_merit.c); and
  3. properly handle data and terminate the program even if trailing "H9" record is not present.

The modifications are too extensive for the changes to be included here. If you need these updates, please contact R. Ricklefs at ricklefs @ csr.utexas.edu.

Issue #: 2009-10

Date: 04 May 2009

Component: sample source code
Version: 1.00
Routine: crd_conv_slr_c/crd_to_cstg_np.c
Problem: When the "11" record return rate/ signal:noise field in a CRD file is set to -1 (not available), -1 is copied into the lunar signal:noise field of the CSTG normal point. This field should be '00' in the CSTG normal point.
Change: Insert
After line 261, insert 

 if (d11.return_rate < 0) np.snr= 0;

Issue #: 2009-9

Date: 04 May 2009
Component: sample source code
Version: 1.00
Routine: crd_chk_c/crd_chk.c
Problem: Crd_chk correctly finds and reports errors when there are non-blanks in header H3 column 23. However it reports the error is in column 22.
Change: Replace
Replace line 227

 nh3_bl[i++] = 22;

with 

nh3_bl[i++] = 23;

Issue #: 2009-8

Date: 04 May 2009
Component: sample source code
Version: 1.00
Routine: crd_chk_c/crd_chk.c
Problem: Crd_chk gives an "out of sequence" error when time of day wraps around to 0. (See Issue #2009-7)
Change: Replace
At lines 699, 666, 631, 600, 577, 541, and 496, replace 

 if (test_sec_of_day < last_sec_of_day)

with 

if (test_sec_of_day < last_sec_of_day &&
              (last_sec_of_day - test_sec_of_day) < 80000)

Issue #: 2009-7

Date: 04 May 2009
Component: manual
Version: 1.00
Section: Data Records
Problem: There is no explicit statement as to whether second of day is allowed to exceed 86400 or required to wrap around to 0 at end of day.
Change:
Add paragraph before section 3.1 -

Seconds of day are, at least for the time being, modulo 86400. In other way, seconds of day must wrap around to 0 at the end of day. Using the pass start and stop time from the H4 header, it will be possible to unambiguously determine the day associated with the second of day. To remove any ambiguiuty, the satellite pass must not be longer than 1 day (which could   occur for geostationary satellites).

Issue #: 2009-6

Date: 12 March 2009
Component: manual
Version: 1.00
Section: Introduction
Problem: The manual suggests filling a numeric field with "-1" and a string field with "na" the when value is not known or not applicable when converting from old format. These should be the fallback values in all cases, not just when converting old data.
Change: Replace 

 When data is converted from an old format to the CRD format, there will be fields (such as skew and kurtosis) that do not exist in the old format.

with 

There will often be cases where the value of a data record field is either unknown or not applicable. This is especially true when data is converted from an old format to the CRD format, since there will be fields (such as skew and kurtosis) that do not exist in the old format.

Issue #: 2009-5

Date: 11 March 2009
Component: sample source code
Version: 1.00
Routine: common_c/write_crd.c
Problem: Satellites launched between 2000 and 2009 have 1 or 2 leading zeros in their ILRS ID. The write routine for the H3 record prints spaces instead of leading zeros.
Change: Replace

On line 55, replace

h3            %8d %4d %8d %1d %1d", header.ilrs_id, header.sic,

with 

h3             %07d %4d %8d %1d %1d", header.ilrs_id, header.sic,

Date: 11 March 2009
Component: sample source code
Version: 1.00
Routine: common_f/write_crd.f
Problem: Satellites launched between 2000 and 2009 have 1 or 2 leading zeros in their ILRS ID. The write routine for the H3 record prints spaces instead of leading zeros.
Change: Replace

On line 64, replace

1000 FORMAT ("h3",1x,a10,1x,i8,1x,i4,1x,i8,1x,i1,1x,i1)

with 

1000 FORMAT ("h3",1x,a10,1x,i8.7,1x,i4,1x,i8,1x,i1,1x,i1)

Issue #: 2009-4

Date: 10 March 2009
Component: sample source code
Version: 1.00
Routine: common_f/read_crd.f
Problem: The Station Epoch Time Scale in the H2 record is treated as a 1 digit field rather than 2 digits.
Change: Replace

On line 47, replace

1000 FORMAT (a10,1x,i4,1x,i2,1x,i2,1x,i1)

with 

1000 FORMAT (a10,1x,i4,1x,i2,1x,i2,1x,i2)

Date: 10 March 2009
Component: sample source code
Version: 1.00
Routine: common_f/write_crd.f
Problem: The Station Epoch Time Scale in the H2 record is treated as a 1 digit field rather than 2 digits.
Change: Replace

On line 47, replace

1000 FORMAT ("h2",1x,a10,1x,i4,1x,i2,1x,i2,1x,i1)

with 

1000 FORMAT ("h2",1x,a10,1x,i4,1x,i2,1x,i2,1x,i2)

Date: 10 March 2009
Component: sample source code
Version: 1.00
Routine: common_c/write_crd.c
Problem: The Station Epoch Time Scale in the H2 record is treated as a 1 digit field rather than 2 digits.
Change: Replace

On line 47, replace

h2            %4d %2d %2d %1d"

with 

h2            %4d %2d %2d %2d"

Issue #: 2009-3

Date: 10 March 2009
Component: sample source code
Version: 1.00
Routine: crd_chk_c/crd_chk.c
Problem: The "data quality alert indicator" is not read correctly.
Change: Replace

On line 47, replace

getifield (crdstr, 62, 1, &h4.data_qual_alert_ind);

with 

getifield (crdstr, 61, 1, &h4.data_qual_alert_ind);

Issue #: 2009-2

Date: 10 March 2009
Component: manual
Version: 1.00
Section: 5.1.1.1 Ftp or Scp
Problem: File extension ".gz" (GNU ZIP) was omitted from the list of common file compression extensions.
Change: Replace 

Files may contain the ".Z", ".z", or ".zip" extensions indicating a particular type of file compression.

with 

Files may contain the ".Z", ".z", ".gz", or ".zip" extensions indicating a particular type of file compression.

Issue #: 2009-1

Date: 10 March 2009
Component: manual
Version: 1.00
Section: 2.4.2 Notes
Problem: Record "C3" contains the field "Epoch delay correction" which section 2.4.2 claims is always applied, while record "C4" contains the field "Estimated Station UTC offset", which may or may not be applied depending on field "Station clock offset and drift applied indicator."
Change: Replace 

"The epoch delay correction has been applied to the data; the value here is for reference only."

with 

"The epoch delay correction has been applied to the data, except in the case of transponders, where there is a choice. See record "C4" in section 2.5 below."

Issue #: 2008-3

Date: 5 December 2008
Component: manual
Version: 1.00
Section: 5.1.1.1 Ftp or Scp
Problem: To support multiple segments files from the same pass, it is necessary to include minutes on the file name.
Change: Replace 

ssss_satname_crd_yyyymmdd_hh_rr.typ

with

ssss_satname_crd_yyyymmdd_hh[mm]_rr.typ

and change 

hh is the start time of pass (hour only, UTC time scale)

to 

hh is the hour when the pass or pass segment begins (UTC time scale) mm is the minute when the pass or pass segment begins (optional)

Issue #: 2008-2

Date: 5 December 2008
Component: sample source code
Version: 1.00
Routine: crd_split_c/crd_split.c
Problem: To support multiple segments files from the same pass, it is necessary to include minutes on the file name.
Change: On lines 100-103, replace

sprintf(out_name,"%04d_%-s_crd_%02d%02d%02d_%02d_%1d.%-3s", h2.cdp_pad_id, target_name, h4.start_year%100, h4.start_mon, h4.start_day, h4.start_hour, h4.data_release, type_str[h4.data_type]);

with

sprintf(out_name,"%04d_%-s_crd_%02d%02d%02d_%02d%02d_%1d.%-3s", h2.cdp_pad_id, target_name, h4.start_year%100, h4.start_mon, h4.start_day, h4.start_hour, h4.start_min, h4.data_release, type_str[h4.data_type]);

(Running test.sh in this directory will now fail as crd_split will produce file names that include minutes which the comparison ".ref" files do not contain.)

Issue #: 2008-1

Date: 29 September 2008
Component: sample source code Version: 1.00
Routine: common_f/read_crdf.f
Problem: A variable in the C0 record reading routine was left unitialized. This problem will be apparent with FORTRAN compilers that do not automatically initialize all variables.
Change: After line 108,add: 

in_arg= .false.