Cassini RADAR Users Guide Second Edition S.D. Wall, R.L. Kirk, B.W. Stiles, A. Hayes, K. Mitchell, R.D. Lorenz, M. Janssen, B. Bills, V. Poggiali, A. Schoenfeld, and the Cassini RADAR Science Team JPL D-102030 September 2019 The authors wish to thank Ellen Stofan, Yanhua Anderson, Rudy Boehmer, Trina Ray, and Reta Bebe for their assistance in producing this document, and especially Charles Elachi, whose guidance and support have led us in this amazingly successful experiment. We also thank Claire Marie-Peterson for helpful comments and superb editing. This publication was prepared for the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement by the United States Government or the Jet Propulsion Laboratory, California Institute of Technology. This guide is dedicated to the memory of Bill Johnson and Steve Ostro. They were fundamental to the success of the Cassini RADAR, and we miss them not only as colleagues, but as friends. Cassini RADAR Users Guide Contents Preface to the Second Edition .................................................................................................................... 1 1 Introduction ............................................................................................................................................... 2 2 The Cassini Spacecraft and Mission ................................................................................................... 4 2.1 The Cassini Orbiter ........................................................................................................................................ 5 2.2 Mission Operations ........................................................................................................................................ 8 2.3 Mission Phases ................................................................................................................................................ 9 3 The Cassini RADAR Experiment ........................................................................................................ 11 3.1 Cassini RADAR Overview ............................................................................................................................ 11 3.2 Experiment Description .............................................................................................................................. 13 3.2.1 RADAR Modes .................................................................................................................................. 13 3.2.2 Secondary RADAR Data Types ..................................................................................................... 14 3.3 Nominal RADAR Observation of Titan .................................................................................................. 15 3.4 RADAR Operation ........................................................................................................................................ 16 3.5 Titan Coverage .............................................................................................................................................. 16 3.6 Other RADAR Coverage ............................................................................................................................. 25 3.6.1 Rings ................................................................................................................................................... 25 3.6.2 Icy Satellites ....................................................................................................................................... 25 3.6.3 Saturn ................................................................................................................................................. 27 3.6.4 Venus, Earth, and Jupiter............................................................................................................... 27 4 RADAR Data Product Overview ........................................................................................................ 29 4.1 Burst-Ordered Data Products (BODPs) ................................................................................................. 30 4.1.1 Product Overview ............................................................................................................................ 31 4.1.2 Short-Burst Data Record (SBDR) ................................................................................................. 31 4.1.3 Long-Burst Data Record (LBDR) .................................................................................................. 34 4.1.4 Altimeter-Burst Data Record (ABDR) .......................................................................................... 34 4.1.5 Data Validation and Archiving ..................................................................................................... 35 4.2 Basic Image Data Records (BIDRs) ......................................................................................................... 35 4.2.1 Data Format and Description ....................................................................................................... 36 4.2.2 Non-Titan BIDRs .............................................................................................................................. 37 4.2.3 Data Validation and Archiving ..................................................................................................... 39 4.3 SARTopo Products ....................................................................................................................................... 39 4.4 Digital Map Products (DMPs) ................................................................................................................... 42 4.4.1 Pass Radiometry Data Records (PRDRs).................................................................................... 43 4.4.2 Pass Scatterometry Data Records (PSDRs) ............................................................................... 45 4.4.3 Global Radiometry Data Records (GRDRs) ............................................................................... 45 4.4.4 Global Scatterometry Data Records (GSDRs) ........................................................................... 47 4.4.5 Global Topography Data Records (GTDRs) .............................................................................. 48 4.4.6 Mosaicked Image Data Records (MIDRs) .................................................................................. 48 4.4.7 Repeat Image Data Records (RIDRs) .......................................................................................... 50 iii Cassini RADAR Users Guide 4.4.8 Digital Topographic Models (DTMs) ............................................................................................51 4.4.9 PDS Label Format for DMPs ......................................................................................................... 52 4.4.10 Validation and Archiving of DMPs .............................................................................................. 52 4.5 Versions of Data Products and Summary of Errata .......................................................................... 54 4.5.1 Definition of Volume Versions ...................................................................................................... 54 4.5.2 Errata Overview ............................................................................................................................... 55 5 Calibration ............................................................................................................................................... 61 6 Titan SAR Swath Summary ................................................................................................................. 66 6.1 Swath Descriptions ...................................................................................................................................... 66 6.2 Ontario Lacus: A Case Study .................................................................................................................... 73 6.3 Huygens Landing Site: A Case Study ..................................................................................................... 74 7 Data Outages, Anomalies, and Related Data Issues .................................................................. 76 7.1 Major Data Outages and Corruption .................................................................................................... 76 7.1.1 Dione/Mimas 00b (Total Loss) ..................................................................................................... 76 7.1.2 The T7 Anomaly ............................................................................................................................... 77 7.1.3 The T60 Anomaly ............................................................................................................................ 78 7.1.4 Iapetus Pass 49 Anomaly .............................................................................................................. 78 7.1.5 The T64 Anomaly ............................................................................................................................ 78 7.1.6 The T69 Anomaly ...........................................................................................................................