Data validation
mission specific
MSL science archives will be validated before being released to the PDS. Validation is accomplished in two parts: validation for scientific integrity and validation for compliance with PDS standards. Science team members are expected to conduct validation for scientific integrity in the course of their analysis of EDRs and their production of RDRs. The details of the science validation process are the responsibility of the instrument Principal Investigators.
Validation for compliance with PDS standards is also the responsibility of each Principal Investigator, with help from the PDS Node that will receive the data products. PDS will provide software tools, examples, and advice to help make this part of the validation as efficient as possible. This validation includes a Design Peer Review of the design and labeling of data products as laid out in the Data Product Software Interface Specification (SIS) documents, and validation of the PDS labels using sample data. The peer reviews for EDR and RDR products will take place well before the start of operations, to allow sufficient time to correct problems. Reviewers will consist of a small group of scientists who represent typical users of the data. The Investigation Scientist or Deputy Project Scientist assigned to the particular instrument and the relevant PDS node will also be represented on the review committee. The review period will last approximately three months and will be conducted mostly by email, culminating in a teleconference if needed. The result of the review will be a list of liens, or problems, that the PI must resolve before the product can pass the review. Another month (or more depending on the nature of the liens) will be allowed for the PI to address the liens. All liens should be resolved by six months before Mars landed operations. The goal is to allow the teams enough time to correct any problems before systematic generation of standard products begins.
After the start of operations, when generation of standard products has begun, each individual product will be validated by the PDS to see that it conforms to PDS standards and to the design specified in the SIS. Validation of individual products will be automated as much as possible. Data providers will be expected to correct errors found during the PDS validation.
Validation of the MER EDRs falls into two primary categories: automated and manual. Automated validation is performed on every EDR product produced for the mission. Manual validation is only performed on a subset.
Automated validation is performed as a part of the archiving process, and is done simultaneously with the archive volume validation. Validations performed include such things as verification that the checksum in the label matches a calculated checksum for the data product (i.e., that the data product included in the archive is identical to that produced by the real-time process), a validation of the PDS syntax of the label, a check of the label values against the database and against the index tables included on the archive volume, and checks for internal consistency of the label items. The latter include such things as verifying that the product creation date is later than the earth received time, and comparing the geometry pointing information with the specified target. As problems are discovered and/or new possibilities identified for automated verification, they are added to the validation procedure.
Manual validation of the data is performed both as spot-checking of data throughout the life of the mission, and comprehensive validation of a subset of the data (for example, a couple of days' worth of data). These products are viewed by a human. Validation in this case includes inspection of the image or other data object for errors (like missing lines) not specified in the label parameters, verification that the target shown/apparent geometry matches that specified in the labels, verification that the product is viewable using the specified software tools, and a general check for any problems that might not have been anticipated in the automated validation procedure.
Phoenix science archives are validated before being released to the PDS. Validation falls into two primary categories: automated and manual. Automated validation is performed on every product produced for the mission. Manual validation is only performed on a subset.
Automated validation is performed as a part of the archiving process, and is done simultaneously with the archive volume validation. Validations performed include such things as verification that the checksum in the label matches a calculated checksum for the data product (i.e., that the data product included in the archive is identical to that produced by the real-time process), a validation of the PDS syntax of the label, a check of the label values against the database and against the index tables included on the archive volume, and checks for internal consistency of the label items. The latter include such things as verifying that the product creation date is later than the earth received time, and comparing the geometry pointing information with the specified target. As problems are discovered and/or new possibilities identified for automated verification, they are added to the validation procedure.
Manual validation of the data is performed both as spot-checking of data throughout the life of the mission, and comprehensive validation of a subset of the data (for example, a couple of days' worth of data). These products are viewed by a human. Validation in this case includes inspection of the image or other data object for errors (like missing lines) not specified in the label parameters, verification that the target shown/apparent geometry matches that specified in the labels, verification that the product is viewable using the specified software tools, and a general check for any problems that might not have been anticipated in the automated validation procedure.