AuxiliaryInstrument version 2

AuxiliaryInstrument_v2

This definition is based on version 3.7 of the Sentinel-1 IPF Auxiliary Product Specification S1-RS-MDA-52-7443

root type

xml record
Instrument auxiliary file definition (AUX_INS). This file includes information related to the instrument required for processing. It is required for data decompression and ISP decoding.

idfield namedefinition
0auxiliaryInstrument
xml record
attribute: schemaVersion
xml string

available: optional

attribute: noNamespaceSchemaLocation
xml string

available: optional


idfield namedefinition
0radarFrequency
ascii double
Radar frequency.

unit: "Hz"
1deltaTGuard1
ascii double
DeltaT Guard 1 parameter from the instrument radar database [s]. This parameter is used to calculate the internal time delay of the extracted reconstructed replicas.

unit: "s"
2deltaTSuppr
ascii double
DeltaT Suppr parameter from the SSPPDU document [s]. This parameter is used to calculate the times within the PRI for the echo, calibration and noise data.

unit: "s"
3deltaTXLatch
ascii double
The time difference between the TX pulse and the latch time as annotated in the radar database [s]. This parameter is used to apply the instrument timing correction.

unit: "s"
4rollSteeringParams
xml record
List of calibration parameter records.

idfield namedefinition
0referenceAntennaAngle
ascii double
Antenna bore sight off nadir angle at the referenceHeight.

unit: "degrees"
1referenceHeight
ascii double
Satellite height at which the instrument elevation angle is aligned with the referenceAntennaAngle.

unit: "m"
2rollSteeringSensitivity
ascii double
Sensitivity of the roll steering versus height.

unit: "degrees/m"
5swathParamsList
xml record
List of calibration parameter records.

attribute: count
xml string


idfield namedefinition
0swathParams
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Calibration parameter record. There must be one record per swath (16 nominal swaths) per polarisation (4 polarisation combinations for SM, IW or EW, 2 for WV) for a minimum total of 58. There are 128 possible swath number values supported by the downlink, so the maximum number of combinations of swath number and polarisation that can be defined is 512.

idfield namedefinition
0swath
xml string
Canonical name of the swath for this swathNumber.
1radarParams
xml record
Radar parameters record.

idfield namedefinition
0azimuthSteeringRate
ascii double
TOPSAR azimuth steering rate. This field is only relevant for IW and EW swaths and is set to 0.0 for SM and WV swaths.
2pulseParams
xml record
Replica pulse parameters. This DSR contains the characteristics for the nominal imaging replica pulse within this swath.

idfield namedefinition
0amplitudeCoefficients
ascii array[dim_0]
Pulse amplitude coefficients of the nominal imaging chirp replica.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float
1phaseCoefficients
ascii array[dim_0]
Pulse phase coefficients of the nominal imaging chirp replica.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float
2nominalTxPulseLength
ascii double
Nominal transmit pulse length [s]. This parameter is used by the pre-processor and the DCE and SLC processors if it is smaller than the Tx Pulse Length (TXPL) extracted from the ISP headers. The nominal transmit pulse length can be set such that the chirp processed bandwidth is small enough to filter out the spurious signals at ±37.5 MHz.
3rxVariationCorrectionParamsList
xml record
attribute: count
xml string


idfield namedefinition
0rxVariationCorrectionParams
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
idfield namedefinition
0rxPolarisation
xml string
Polarisation to which this set of receive correction parameters applies. "H" or "V".
1gainTrendCoefficients
ascii array[dim_0]
Gain trend correction coefficients.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float
2gainOvershootCoefficients
ascii array[dim_0]
Gain overshoot correction coefficients.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float
4onBoardDecimationFilterParamsList
xml record
attribute: count
xml string


idfield namedefinition
0onBoardDecimationFilterParams
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
idfield namedefinition
0rxPolarisation
xml string
Polarisation to which this set of parameters applies. "H" or "V".
1powerTransferFunction
xml record
idfield namedefinition
0frequencyIncrement
xml float
The frequency increment.
1values
ascii array[dim_0]
Power transfer function coefficients.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float
2spuriousFrequencies
ascii array[dim_0]
List of the known spurious frequencies.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float

available: optional
6internalCalibrationParamsList
xml record
Internal calibration instrument parameters. This record contains swath/polarisation channel dependent parameters related to the instrument. There must be one record per swath (16 nominal swaths) per polarisation (4 polarisation combinations for SM, IW or EW, 2 for WV) for a minimum total of 60. There are 128 possible swath number values supported by the downlink, so the maximum number of combinations of swath number and polarisation that can be defined is 512.

attribute: count
xml string


idfield namedefinition
0internalCalibrationParams
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Internal calibration instrument parameters. This record contains swath/polarisation channel dependent parameters related to the instrument. There must be one record per swath (16 nominal swaths) per polarisation (4 polarisation combinations for SM, IW or EW, 2 for WV) for a minimum total of 58. There are 128 possible swath number values supported by the downlink, so the maximum number of combinations of swath number and polarisation that can be defined is 512.

idfield namedefinition
0swath
xml string
Canonical name of the swath.
1polarisation
xml string
Polarisation. Used along with the swathNumber to index the applicable internalCalibrationParams record.
2timeDelay
ascii double
Internal time delay [s] to be applied to the reference chirp used for range processing. The IPF only uses this parameter when the time delay cannot be derived from the extracted PG replicas due to invalid (poor quality) reconstructed PG replicas. Nominally, the time delay is estimated as the average internal time delay from the all of the extracted PG replicas and it compensates for the dual polarisation mis-registration.

unit: "s"
3nominalGain
xml record
Complex gain to be applied to the range match filter when the nominal chirp is used. It is used to compensate for the amplitude and phase differences between the two channels in dual polarisation data.

idfield namedefinition
0re
ascii double
1im
ascii double
4extractedGain
xml record
Complex gain to be applied to the range match filter when the extracted replica is used. It is used to compensate for the amplitude difference between the two channels in dual polarisation data. Phase difference compensation is not done when the extracted replica is used since the phase difference is already embedded in the extracted replicas.

idfield namedefinition
0re
ascii double
1im
ascii double
5pgProductModel
xml record
Modeled PG product. The model is relative to the ascending node of the current orbit.

idfield namedefinition
0pgModelInterval
ascii double
Interval between adjacent PG Product values in the list.

unit: "s"
1values
ascii array[dim_0]
Array of modeled complex PG model values. The pattern contains attribute "count" complex floating point values separated by spaces. The first value in the array corresponds to the time at the ascending node of the current orbit.

dim_0: int(str(@count))

attribute: count
ascii string

ascii complex
ascii record
idfield namedefinition
0real
ascii float
1imaginary
ascii float
6pgReference
xml record
Reference absolute PG value that will be defined by offline analysis of the acquired data. PG values used by the IPF will be normalised by this PG reference value.

idfield namedefinition
0re
ascii double
1im
ascii double
7swstBias
ascii double
SWST bias.

unit: "s"
8azimuthTimeBias
ascii double
Azimuth time bias.

unit: "s"
9noise
ascii double
Nominal noise value if noise used in processing if no noise value can be calculated from the downlink.
10replicaPccParamsList
xml record
List of PCC decoding control parameters for the extracted replicas at nominal imaging bandwidth.

attribute: count
xml string


idfield namedefinition
0pccParams
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
PCC decoding parameters for controlling the order and way in which calibration pulses are decoded during processing. There are a minimum of 5 entries in the list, one for each nominal calibration pulse, and a maximum of 6 entries in the list for the transmit H polarisation which includes an additional isolation pulse.

idfield namedefinition
0signal
xml string
Signal type.
1order
ascii array[dim_0]
PCC pulse selection order. This is a list of integers separated by spaces that defines the order in which the pulses are combined using the method below.

dim_0: int(str(@count))

attribute: count
ascii string

ascii int32
2method
xml string
Method to use to combine the calibration pulses selected by the order above. The PCC2 method subtracts the pulses in order and averages over the number of pulses. The Average method adds the pulses in order and averages over the number of pulses. The Isolation Subtraction method finds the PCC parameters record for the corresponding isolation pulse and subtracts the selected isolation pulse from the selected nominal pulse.
11pgPccParamsList
xml record
List of PCC decoding control parameters for the PG replicas at 100 MHz bandwidth

attribute: count
xml string


idfield namedefinition
0pccParams
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
PCC decoding parameters for controlling the order and way in which calibration pulses are decoded during processing. There are a minimum of 5 entries in the list, one for each nominal calibration pulse, and a maximum of 6 entries in the list for the transmit H polarisation which includes an additional isolation pulse.

idfield namedefinition
0signal
xml string
Signal type.
1order
ascii array[dim_0]
PCC pulse selection order. This is a list of integers separated by spaces that defines the order in which the pulses are combined using the method below.

dim_0: int(str(@count))

attribute: count
ascii string

ascii int32
2method
xml string
Method to use to combine the calibration pulses selected by the order above. The PCC2 method subtracts the pulses in order and averages over the number of pulses. The Average method adds the pulses in order and averages over the number of pulses. The Isolation Subtraction method finds the PCC parameters record for the corresponding isolation pulse and subtracts the selected isolation pulse from the selected nominal pulse.
7timelineList
xml record
Timeline list. This element contains a list of records that describe the expected packet transmission sequence for each of the Sentinel-1 SAR modes. The SPPDU document allows for 48 entries numbered from 0-47. At minimum, this list must include 9 entries: an entry for each instrument measurement mode.

attribute: count
xml string


idfield namedefinition
0timeline
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Each timeline element describes the expected packet transmission sequence for one of the operational modes of the satellite. The SPPDU [A-12] allows for 48 entries numbered from 0-47. At minimum, this list must include 10 entries: an entry for each instrument measurement mode (S1, S2, S3, S4, S5-N, S5-S, S6, IW, EW and WV).

idfield namedefinition
0eccNumber
ascii int64
Event Control Code (ECC) number. This field uniquely identifies the ECC program number for this instrument mode and is used by the IPF for timeline selection.
1mode
xml string
Instrument mode. This field identifies the instrument mode to which this timeline entry applies.
2sequenceList
xml record
Sequence list. This element is a list of activity sequences that together form the expected transmission sequence from the SAR instrument for the data take. The number of sequences is arbitrary but there are 5 slots nominally allocated for 1- an initial noise measurement; 2- an initial calibration sequence; 3- image acquisition; 4- final calibration sequence; and, 5- final noise measurement.

attribute: count
xml string


idfield namedefinition
0sequence
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Calibration parameter record. There must be one record per swath (16 nominal swaths) per polarisation (4 polarisation combinations for SM, IW or EW, 2 for WV) for a minimum total of 58. There are 128 possible swath number values supported by the downlink, so the maximum number of combinations of swath number and polarisation that can be defined is 512.

idfield namedefinition
0name
xml string
The name of the activity within the data acquisition to which this sequence belongs. This field is not used by the IPF for processing. It is for informative purposes only and so the range of the field is unbounded.
1repeat
ascii uint8
Sequence repeat flag. For the imaging sequence, this field shall be set to “true” to indentify the ispList that represents the imaging operation. This field shall be set to “false” for all other sequences.

mapping: "false" -> 0

mapping: "true" -> 1
2ispList
xml record
ISP list. This element contains contains a list of the expected packets within this sequence in the order they should be received. The number of ISP entries is arbitrary but there are 30 slots defined to capture the worst case EW echo acquisition with PCC2 sequences at the end of each burst.

attribute: count
xml string


idfield namedefinition
0isp
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
The ISP element describes one unique, or a series of unique transmission packets. The packets are identified by the packet signal type and contain the number of PRIs expected for this packet type.

idfield namedefinition
0swath
xml string
Canonical name of the swath to which this packet belongs.
1signal
xml string
Signal type.
2bandwidth
xml string
Signal bandwidth type.
3numPri
ascii uint32
The number of packets of this signal type expected in series.
3swathMapList
xml record
Swath mapping list. This element is a list of the swaths applicable to this ECC program and provides a mapping between the swath number fields in the source packet headers and the logical instrument swath name to which they apply.

attribute: count
xml string


idfield namedefinition
0swathMap
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Calibration parameter record. There must be one record per swath (16 nominal swaths) per polarisation (4 polarisation combinations for SM, IW or EW, 2 for WV) for a minimum total of 58. There are 128 possible swath number values supported by the downlink, so the maximum number of combinations of swath number and polarisation that can be defined is 512.

idfield namedefinition
0swathNumber
ascii int64
The swath number from the source packet secondary header to map to a particular logical swath within the instrument mode.
1swath
xml string
Canonical name of the swath to which this packet belongs.
8decodingParams
xml record
Raw data decoding parameters. This DSR contains the raw data decoding tables and parameters that the IPF requires to perform image processing.

idfield namedefinition
0huffmanLutList
xml record
Huffman decoding LUT list. This element contains the Huffman decoding LUTs required to retrieve the HCode value from FDBAQ encoded user data. There is one LUT for each Bit Rate Code for a total of 5.

attribute: count
xml string


idfield namedefinition
0huffmanLut
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Huffman decoding LUT. This element contains the Huffman binary tree values for the applicable Bit Rate Code. The MCode is recovered by applying the values in the decoding LUT to the extracted HCode.

idfield namedefinition
0baqCode
xml string
Bit Rate Code (as extracted from the BAQ block) to which this LUT applies.
1values
ascii array[dim_0]
Huffman binary decoding tree values. The tree is implemented using a simple binary coding in which starting at the root, the left side is defined and then the right side is defined. Each node is identified by a 0 followed by a 0 or 1 representing the value of the node. Each leaf is identified by a 1 followed by a 0 or 1 representing the value of the leaf followed by 4 bits representing the MCode value. This encoding scheme is a proposal and will be confirmed prior to CDR.

dim_0: int(str(@count))

attribute: count
ascii string

ascii int32
1nrlLutList
xml record
Normalised Reconstruction Levels LUT list. This element contains the NRL LUTs required to retrieve the normalised reconstructed sample values from the BAQ encoded data. There is one LUT per BAQ mode/FDBAQ Bit Rate Code for a total of 8 LUTs.

attribute: count
xml string


idfield namedefinition
0rlLut
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Reconstruction Levels LUT. This LUT contains the RL values used to retrieve the reconstructed sample values from the BAQ encoded data. The RL in the table are indexed by: 1. the Bit Rate Code extracted from the BAQ data block for FDBAQ compression; and, 2. the BAQ mode (3-bit, 4-bit or 5-bit) for BAQ compression.

idfield namedefinition
0baqCode
xml string
Index code for which the LUT applies. For FDBAQ compression this is the Bit Rate Code extracted from the BAQ block and for BAQ compression this is the BAQ mode.
1values
ascii array[dim_0]
NRL LUT values. This element contains fifteen double precision floating point values separated by spaces, one entry for each MCode value. Note that some MCodes are not applicable for some FDBAQ and BAQ modes so in this case the entry shall be "NaN" to signify an invalid index.

dim_0: int(str(@count))

attribute: count
ascii string

ascii double
2srlLutList
xml record
Simple Reconstruction Parameters LUT list. This element contains the Simple Reconstruction Parameters LUTs required to retrieve the simple reconstructed sample values from the BAQ encoded data. There is one LUT per BAQ mode/FDBAQ Bit Rate Code for a total of 8 LUTs.

attribute: count
xml string


idfield namedefinition
0rlLut
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Reconstruction Levels LUT. This LUT contains the RL values used to retrieve the reconstructed sample values from the BAQ encoded data. The RL in the table are indexed by: 1. the Bit Rate Code extracted from the BAQ data block for FDBAQ compression; and, 2. the BAQ mode (3-bit, 4-bit or 5-bit) for BAQ compression.

idfield namedefinition
0baqCode
xml string
Index code for which the LUT applies. For FDBAQ compression this is the Bit Rate Code extracted from the BAQ block and for BAQ compression this is the BAQ mode.
1values
ascii array[dim_0]
NRL LUT values. This element contains fifteen double precision floating point values separated by spaces, one entry for each MCode value. Note that some MCodes are not applicable for some FDBAQ and BAQ modes so in this case the entry shall be "NaN" to signify an invalid index.

dim_0: int(str(@count))

attribute: count
ascii string

ascii double
3sigmaFactorLut
ascii array[dim_0]
Sigma Factors LUT. This LUT contains the values used to upscale the normalised reconstructed samples. The sigma factors in the table are indexed by the Threshold Index (THIDX) extracted from the BAQ block. This vector contains 255 single precision floating point numbers separated by spaces.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float
4thresholdLutList
xml record
Raw data decoding control LUT list. This element contains the parameters required to decode the BAQ and FDBAQ encoded data.

attribute: count
xml string


idfield namedefinition
0thresholdLut
xml array[dim_0]
dim_0: determined automatically from xml file
xml record
Threshold LUT containing the thresholds needed to decode the BAQ and FDBAQ encoded data. There is one record for each of the BAQ-modes/FDBAQ-BRCs for a total of 8.

idfield namedefinition
0baqCode
xml string
BAQ-mode/FDBAQ-BRC to which this set of thresholds applies.
1thidxThreshold
ascii int32
THIDX threshold used to determine whether to use the simple reconstruction method or the normal reconstruction method. If the THIDX extracted from the data is less than or equal to this threshold, then the simple reconstruction method is used; otherwise, the normal reconstruction method is used.
2mCodeThreshold
ascii int32
Mcode threshold used in simple reconstruction to determine whether to use the extracted Mcode or the the simple reconstruction LUT. If the Mcode extracted from the data is less than this threshold, then the extracted Mcode is used; otherwise, the simple reconstruction LUT is used.
5tguLut
ascii array[dim_0]
TGU temperature LUT. This LUT contains the values that are used to convert the TGU temperature codes extracted from the sub-commutated ancillary data in the ISP headers into the correct temperature value [degrees C]. The LUT contains a list of 128 single-precision floating values separated by spaces with the index of each entry, numbered 0 .. 127, corresponding to the code for which the temperature value applies. The index of each entry represents the code to convert, with the first entry in the list starting at index/code 0 and incrementing by 1 for each subsequent entry.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float
6tileLut
ascii array[dim_0]
Tile temperature LUT. This LUT contains the values that are used to convert the EFE and active TA temperature codes extracted from the sub-commutated ancillary data in the ISP headers into the correct temperature value [degrees C]. The LUT contains a list of 256 single-precision floating values separated by spaces with the index of each entry, numbered 0 .. 255, corresponding to the code for which the temperature value applies. The index of each entry represents the code to convert, with the first entry in the list starting at index/code 0 and incrementing by 1 for each subsequent entry.

dim_0: int(str(@count))

attribute: count
ascii string

ascii float

detection rule

This product definition is applicable if a product matches the following rule:

exists(/auxiliaryInstrument@schemaVersion) and
at(/auxiliaryInstrument@schemaVersion,
str(.) == "3.7")