| Date: | 2008-08-13 10:35:00 | |
| Sender: | Mike Pearlman and Randy Ricklefs <Mike Pearlman <mpearlman@cfa.harvard.edu>> | |
| Subject: | [SLR-Mail] No. 1708: Conversion to CRD Format | |
| Author: | Mike Pearlman and Randy Ricklefs | |
| Content: | ******************************************************************************** SLR Electronic Mail 2008-08-13 10:35:00 UTC Message No. 1708 ******************************************************************************** Author: Mike Pearlman and Randy Ricklefs Subject: Conversion to CRD Format Subject: Conversion to CRD Format Subject: Conversion to CRD Format Dear Colleagues: As you are aware, the ILRS is adopting the new Consolidated laser Ranging Data (CRD) format for its ranging data. SLRMail message 1693 from Randy Ricklefs announced that the format is now ready, and preparations for its acceptance at the Operations and Data Centers are underway. The new format will be used for normal point, full- rate, and sampled engineering data. All stations and analysis centers should begin the conversion process. Changing formats is always a challenge, but the new format is necessary to accommodate recent improvements in ranging technology and the challenge of more stringent program requirements. Higher pulse repetition rates, higher accuracy requirements, transponder operations, and the need for increased supporting information make the change necessary now. Several projects such as T2L2 (on board the Jason-2 satellite) and LRO-LR are already dependent upon CRD for increased range and resolution capability. The CRD documentation, sample source code, and validation procedures are available on the ILRS Web site at: http://ilrs.gsfc.nasa.gov/products_formats_procedures/crd.html Please access this material and begin the process. The document includes data examples, a section on implementing the format, and a section describing how the data fields in the CRD format can be used by stations and analysts to improve laser ranging data quality. The sample code implements the changes in the document, and includes programs to compare normal point and full-rate files in the CRD and old formats. These new programs can help the stations and Operations Centers with validating data in the new format. Please examine and compare your new and old format data carefully prior to submission. Once the conversion is made at a station, data should be submitted in both the old and the CRD formats either through HTSI or EDC. The verification process, first by the Operations Center (HTSI) and then by the Analysis Centers should take 30 - 60 days. Stations will issue data in both CRD and current normal point formats until authorized to cease the old format by the Operations Center. The Operation Center will continue to generate and submit the old format data to maintain two parallel data files (old and CRD) prior to January 2010, when all archiving of data in the old formats will cease. Two-way conversion programs are available in the sample code for those who find the need to handle historic data files. More details of this process are included in the ”validation procedures” document on the web site. The schedule is as follows: Now: Stations and Analysis Centers should begin the conversion process, using the furnished software to verify their processes; October 15: HTSI will be ready to accept data in CRD format and provide quality control scrutiny and new/old NP data validation; As they are ready, stations can start submitting data in CRD in addition to the old formats to HTSI or EDC; verification by the Operations Center will require about 30 days from the date of submission; December 1: Selected Analysis Centers will be ready to compare and scrutinize the data in both the old and new formats for stations in the routine analysis process; this validation activity should take about 30 days; April 15, 2009: All stations must submit data in the CRD format; Dec 31, 2009: All submission of the old format will cease. Only data in CRD format will be submitted to and archived at the data files at the Data Centers. Questions regarding the CRD format should be directed to Randy Ricklefs at: ricklefs@csr.utexas.edu The development of the format has been discussed at the last several workshops and has evolved with the input and guidance from the full ILRS community. We wish to thank everyone for his and her help in this process. Dr. Michael R. Pearlman Harvard-Smithsonian Center for Astrophysics 60 Garden St. Cambridge MA 02138 tel. (617) 495-7481 fax. (617) 496-0121 e-mail. mpearlman@cfa.harvard.edu From: ”Mike Pearlman” ******************************************************************************** |