The ISIS3 Attached Spice Format

Overview

Running the spiceinit application with attach=true will attach all of the SPICE data required by the camera model directly to the Cube. There are 6 locations information is added to the Cube:

• The Kernels group
• The NaifKeywords group
• The InstrumentPointing Table
• The InstrumentPosition Table
• The BodyRotation Table
• The SunPosition Table

The following sections outline what is stored in each of these locations. The spiceinit application documentation shows what textual information is added to these locations.

The Kernels Group

Before spiceinit

The Kernels group is already a part of the Cube label after ingestion (it is nested under the IsisCube object). Usually, the only information it contains after ingestion is the NaifFrameCode keyword. The NaifFrameCode keyword contains the NAIF code for the instrument. So, information about the instrument will be stored as INS{NaifFrameCode}_{Some property} in the NAIF kernels. For example the NaifFrameCode for Kaguya Terrain Camera 2 is -131371. So, the focal length for Kaguya Terrain Camera 2 is stored as INS-131371_FOCAL_LENGTH. Usually, the NAIF ID for the instrument is also the NAIF ID for the sensor reference frame. If this is not the case, then there will be also be a NaifCkCode keyword in the Kernels group that contains the NAIF ID for the sensor reference frame.

After spiceinit

All of the kernels used will be added to the Kernels group under the following keywords:

• LeapSecond
• TargetAttitudeShape
• TargetPosition
• InstrumentPointing
• Instrument
• SpacecraftClock
• InstrumentPosition
• InstrumentAddendum

If a shapemodel is is used, then that shapemodel will also be specified by the ShapeModel keyword. The InstrumentPositionQuality and InstrumentPointingQuality keywords will specify the quality of the kernels used for the InstrumentPositon and InstrumentPointing Tables. Finally, the CameraVersion keyword specifies the version of the camera model that the Cube will now work with.

The NaifKeywords Group

The NaifKeywords group is not a part of the Cube prior to spiceinit being run. After spiceinit, the group is located at the very end of the Cube label.

This group contains all of the keywords and values collected from the SPICE kernel pool. Some examples what is usually contained in the NaifKeywords group are the target body radii, the instrument focal length, distortion model coefficients, and the transformations between image pixels and detector pixels.

The sensor model specifies what is contained in the NaifKeywords group. Keywords and values are added to the NaifKeywords group by the following Spice class methods (methods in italics are protected):

• getDouble
• getInteger
• getString
• readValue
• storeResult
• storeValue

The sensor model and its maps use these methods to get any keyword values they need from the SPICE kernel pool. The keyword and its values are then stored in the NaifKeywords group and any future calls to access them query the NaifKeywords group instead of the SPICE kernel pool.

ISIS Tables

The InstrumentPointing Table, InstrumentPosition Table, BodyRotation Table, and SunPosition Table are ISIS Tables. These are tables of binary information stored on the Cube file. Each Table consists of two parts; the label, and the binary data. The labels for all of the Tables in a Cube file are located in the Cube label after the IsisCube object. Each label is an object called Table, each Table is identified by the values of its Name keyword. So, the InstrumentPointing Table label is the Table object whose Name keyword has a value of InstrumentPointing.

The InstrumentPointing Table

The InstrumentPointing Table is not a part of the Cube prior to spiceinit being run. After spiceinit, the label for the Table is located after the IsisCube object in the Cube label and the binary table data is located at the end of the file.

The InstrumentPointing Table Label

The Table label is a PVL object that contains information about the binary table data and some additional rotational data. The location and format of the binary data is described by the StartByte, Bytes, Records, and ByteOrder keywords