AATSR Quality and Classification Flags Author(s) : IDEAS+ AATSR QC Team The purpose of this document is to provide users with information on quality and classification (i.e. cloud and surface) flags contained within (A)ATSR Level 1B and Level 2 products generated by the 3rd (A)ATSR Reprocessing, and within (A)ATSR Level 1B products generated by the 4th (A)ATSR Reprocessing. IDEAS+-VEG-OQC-REP-2982 Issue 1.0 27 September 2018 AATSR Quality and Classification Flags Issue 1.0 AMENDMENT RECORD SHEET The Amendment Record Sheet below records the history and issue status of this document. ISSUE DATE REASON 1.0 27 September 2018 Initial release TABLE OF CONTENTS 1. INTRODUCTION ........................................................................................................................ 4 1.1 Purpose and Scope ............................................................................................................... 4 1.2 Structure of the Document .................................................................................................... 4 1.3 Referenced Documentation .................................................................................................. 4 1.4 Definition of Terms ................................................................................................................ 5 1.5 Acronyms and Abbreviations ................................................................................................ 6 RD 2. 3 (A)ATSR REPROCESSING ................................................................................................ 7 2.1 Level 1B AATSR Products .................................................................................................... 7 2.1.1 Quality Flags ................................................................................................................... 8 2.1.1.1 Confidence Words MDS ............................................................................................ 8 2.1.1.2 Pixel exception values ............................................................................................... 9 2.1.1.3 Record quality indicator in the MDS header field .................................................... 10 2.1.1.4 Attachment flag in the ADS records ........................................................................ 10 2.1.2 Classification Flags ....................................................................................................... 10 2.1.2.1 Cloud Words MDS ................................................................................................... 10 2.1.3 Quality Flag Examples .................................................................................................. 11 2.1.3.1 Night-time flags ........................................................................................................ 11 2.1.3.2 Cosmetic fill flag ....................................................................................................... 12 2.1.3.3 Saturation flag .......................................................................................................... 12 2.1.4 Classification Flag Examples ........................................................................................ 13 2.1.4.1 Land flag .................................................................................................................. 13 2.1.4.2 Cloud and cloud test flags ....................................................................................... 13 2.2 Level 2 AATSR Products .................................................................................................... 14 2.2.1 AATSR L2 NR Products ............................................................................................... 14 2.2.1.1 Nadir and Combined field contents.......................................................................... 15 2.2.1.2 Confidence word field contents................................................................................ 16 2.2.2 AATSR L2P ARC-like Product ...................................................................................... 17 2.2.3 AATSR UoL L2 LST Products ...................................................................................... 18 2.2.4 Flag examples from SST L2P and UoL LST (NetCDF format) .................................... 19 TH 3. 4 (A)ATSR REPROCESSING .............................................................................................. 21 3.1 Level 1B (A)ATSR Products ................................................................................................ 21 3.1.1 Quality Flags ................................................................................................................. 21 3.1.1.1 Pixel exception values (MDS) .................................................................................. 21 3.1.1.2 Whole-product quality information (manifest) .......................................................... 22 3.1.2 Classification Flags ....................................................................................................... 23 3.1.2.1 Confidence Words (Flags ADS)............................................................................... 23 3.1.2.2 Cloud and Bayesian Cloud Words (Flags ADS) ...................................................... 24 3.1.2.3 Whole-product pixel classification summary (manifest) .......................................... 26 3.1.2.4 Pointing Words (Flags ADS) .................................................................................... 26 3.1.3 Quality Flag Examples .................................................................................................. 26 Page 2 of 31 AATSR Quality and Classification Flags Issue 1.0 3.1.3.1 Exception values ...................................................................................................... 26 3.1.4 Classification Flag Examples ........................................................................................ 28 3.1.4.1 Cloud, confidence and pointing ............................................................................... 28 3.1.4.2 Cosmetic fill .............................................................................................................. 30 3.2 Level 2 AATSR Products .................................................................................................... 30 4. ANNEX A ................................................................................................................................. 31 Page 3 of 31 AATSR Quality and Classification Flags Issue 1.0 1. INTRODUCTION 1.1 Purpose and Scope This document sets out to explain the quality and classification flags contained within AATSR Level 1B and Level 2 products from the 3rd (A)ATSR Reprocessing (see Section 2), and AATSR Level 1B products from the 4th (A)ATSR Reprocessing (see Section 3). Quality and classification flags contained within ATSR-1 and ATSR-2 products are not specifically displayed in this document but they are the same as those contained within AATSR products, where they share the same product format. Full technical details on each reprocessing, and their products, are available from a number of sources which include the AATSR Handbook [RD-1], the Envisat Product Specifications (Volume 7: AATSR Products Specifications) [RD-2] document, and the (A)ATSR FAST L1B Product Definition [RD-3] document, which concerns products in the new SLSTR-like product format (to be introduced by the 4th (A)ATSR Reprocessing). Information on access to the (A)ATSR products at ESA can be found at https://earth.esa.int/web/guest/data-access/browse-data-products. If users have any further queries, the ESA Contact Us link can be used. General quality information can also be found in [RD-4]. 1.2 Structure of the Document This document is divided into a number of sections which are briefly described below: 1 INTRODUCTION This chapter provides explanations of the document’s purpose and scope, structure, referenced documentation, the definition of terms, and a list of the acronyms and abbreviations. 2 3RD (A)ATSR REPROCESSING This chapter provides detailed descriptions of the quality and classification flags contained within the AATSR products generated by the 3rd (A)ATSR Reprocessing. 3 4TH (A)ATSR REPROCESSING This chapter provides detailed descriptions of the quality and classification flags to be contained within the AATSR products generated by the 4th (A)ATSR Reprocessing. 4 ANNEX A The Annex contains ancillary information relevant to the preceding sections. 1.3 Referenced Documentation The following is a list of documents with a direct bearing on the content of this report. Where referenced in the text, these are identified as RD-n, where 'n' is the number in the list below: [RD-1] European Space Agency: Envisat AATSR Product Handbook, Issue 2 Revision 2, 27 February 2007. Accessed at: http://envisat.esa.int/handbooks Page 4 of 31 AATSR Quality and Classification Flags Issue 1.0 [RD-2] Envisat-1 Products Specifications: AATSR Product Specifications (Volume 7), IDEAS-SER-IPF-SPE-0288, Issue 4 Revision C, 05 September 2013. Accessed at: https://earth.esa.int/documents/700255/2042507/Vol-07- Aats4C.pdf/71cd7964-7860-4df7-abe5-5042b76cc31f [RD-3] (A)ATSR Expert Support Laboratory FAST L1b Product Definition, PO-TN-RAL- AT-0568, Issue 1.4, 19 March 2018. Accessed at: https://earth.esa.int/documents/700255/2482719/PO-TN-RAL-AT-0568+- +FAST+Level+1b+Product+Definition+Issue+1.4/ecb0344b-32c4-4172-b7a7- e32bddf40309