# ARTS built-in documentation server

## Workspace Method retrievalAddPointingZa

### Description

Same as jacobianAddPointingZa but also adds a new block to covmat_sx using the matrices in covmat_block and covmat_inv_block. If covmat_inv_block is non-empty, it is used as inverse for the added block which avoids its numerical computation. For number and order of elements added to x, see jacobianAddPointingZa.

**Authors: **Simon Pfreundschuh

### Synopsis

retrievalAddPointingZa( | covmat_sx, jacobian_quantities, jacobian_agenda, covmat_block, covmat_inv_block, sensor_pos, sensor_time, poly_order, calcmode, dza ) |

### Variables

OUT+IN | covmat_sx | (CovarianceMatrix) | Covariance matrix of a priori distribution This covariance matrix describes the Gaussian a priori distribution for an OEM retrieval. |

OUT+IN | jacobian_quantities | (ArrayOfRetrievalQuantity) | The retrieval quantities in the Jacobian matrix. |

OUT+IN | jacobian_agenda | (Agenda) | Pure numerical Jacobian calculation agenda. |

IN | covmat_block | (Sparse) | Holds matrices used to set blocks in covmat_sx and covmat_se. |

IN | covmat_inv_block | (Sparse) | Holds matrices used to set the inverse blocks in covmat_sx and covmat_se. |

IN | sensor_pos | (Matrix) | The sensor position for each measurement block. |

IN | sensor_time | (ArrayOfTime) | The time for each measurement block. |

GIN | poly_order | (Index, Default: 0) | Order of polynomial to describe the time variation of pointing off-sets. |

GIN | calcmode | (String, Default: "recalc") | Calculation method. See above |

GIN | dza | (Numeric, Default: 0.01) | Size of perturbation to apply (when applicable). |