Package Overview

InstruPy is a python package to calculate (satellite) observation data metrics for a given instrument and associated viewing geometry (access events).

_images/instrupy_block_diagram.png

The high-level function of the InstruPy package is shown in the figure. The package ingests access data i.e. the remote-sensing satellite states (time, position, velocity) information, and instrument specifications (for which the access data was generated), and outputs data metrics of observation.

For a detailed description see the following articles:

    1. Ravindra, R. Ketzner, S. Nag, “Earth Observation Simulator (EO-SIM): An Open-Source Software for Observation Systems Design”, IEEE International Geoscience and Remote Sensing Symposium, Brussels Belgium, July 2021.

    1. Ravindra, S. Nag, “Instrument Data Metrics Evaluator for Tradespace Analysis of Earth Observing Constellations”, IEEE Aerospace Conference, Big Sky, Montana, March 2020.

    1. Nag, V. Ravindra, J.J. LeMoigne “Instrument Modeling Concepts for Tradespace Analysis of Satellite Constellations”, IEEE Sensors Conference, Delhi, India, October 2018.

Currently there are four instrument models supported:

  1. Basic Sensor (Basic Sensor Model, instrupy.basic_sensor_model — Basic Sensor Model)

  2. Passive Optical Sensor (Passive Optical Scanner Model, instrupy.passive_optical_scanner_model — Passive Optical Scanner Model)

  3. Synthetic Aperture Radar (Synthetic Aperture Radar Model, instrupy.synthetic_aperture_radar_model — Synthetic Aperture Radar Model)

  4. Radiometer (Radiometer Model, instrupy.radiometer_model — Radiometer Model)

Glossary of terms used in the package

  • Satellite and spacecraft are synonymous.

  • Instrument, payload and sensor are synonymous.

  • Grid-point, ground-point and target-point synonymous.

  • Pixels vs Detectors

    Pixels: Refer to ground pixels imaged. Dimensions vary according to imaging geometry. Detectors: Refer to physical detector elements on the imaging aperture.

  • Access vs Coverage

    • Sometimes access and coverage are used synonymously.

    • Other times access refers to a target falling under a sensor FOV while coverage includes an additional condition that the satellite should be able to be make an observation. For example for an optical sensor a ground-point may fall under the sensor FOV (which is regarded as an access event), but may not be observable because it is night-time (no coverage).

Coding Conventions

  • Variables denoting physical quantities, unless otherwise indicated are always in S.I. units.