SpacecraftEstimation Module

Directory List

AttitudeEstimation DemoFuns Demos/AttitudeEstimation
Demos/OpticalNavigation Demos/OrbitEstimation Demos/StarSimulation
Demos/StellarAttDet Demos/UKF EstimationData
OpticalNavigation OrbitEstimation RelativeState
SensorMeas StarCentroiding StarProcessing
StarSimulation StarVisualization StellarAttDet
StellarCatalog StellarData StellarEphem
StellarModels


AttitudeEstimation

A standard discrete Kalman Filter.
Gyro Kalman Filter
A Kalman Filter using the sun vector and the earth vector for GEO.
Outputs the set of acceptable attitude measurements from vectors.
Estimates gyro bias using a steady state Kalman Filter.
An attitude determination system using roll/yaw gyrocompassing.
Estimates roll and yaw given a roll measurement and body rates.
An attitude determination system using a sun and earth vector.
Attitude determination using a sun, earth and magnetic field vectors.
An attitude determination system using vector measurements.
Unscented Kalman Filter measurement update step.
Implements yaw/roll gyrocompassing attitude estimation.

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DemoFuns

Pressure given fuel mass for a blowdown propulsion system.
A linear measurement. Returns y = x.
Transformation matrix from EF to NEU.
Point mass gravity model.
Model a spacecraft as an isothermal radiator with an input state.
Right-hand-side for an isothermal spacecraft model.
Right-hand-side for a cartesian orbit.
Right-hand-side for a thruster based on the input pulsewidth.
Telescope model for satelite tracking.

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Demos/AttitudeEstimation

Performs a covariance analysis of different gyros.
Test a Kalman Filter using a sun vector and the earth vector.
Simulate attitude determination for a momentum bias spacecraft.
Test a sun and earth sensor attitude determination system.
Test attitude determination with sun, earth and magnetometer.
Demonstrate the yaw/roll gyrocompassing system.

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Demos/OpticalNavigation

EarthMoonTraj.matSaved trajectory that passes behind the moon.
Demonstrate optical navigation in earth geosynchronous transfer orbit.
Optical navigation demo in the Earth-Moon system.
Estimate the orbit position using a range and three stars
Generate a trajectory for optical navigation in the Earth-Moon system
Demonstrate orbit estimation using a UKF and optical navigation.
Demonstrate orbit estimation using a UKF and planet centroid data.
Demonstrate orbit estimation using a UKF and lunar landmark data.

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Demos/OrbitEstimation

Demonstrate batch orbit determination
Demonstrates the image matching algorithm, FImage.
Demonstrates the image matching algorithm.
Demonstrates orbit disturbance estimation using linearized equations.
Test the orbit Kalman Filter with omni and GPS measurements.
Demonstrate Sequential Batch Least-Squares Orbit Determination
Test stellar navigation. Uses a random star catalog.
Compares UKF.
Demonstrate orbit estimation using a UKF with full state measurements.
Demonstrate orbit estimation using UKFPredict and UKFUpdate.
Demonstrate orbit estimation using UKFPredict and UKFUpdate.
UKF/UKS demonstration.

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Demos/StarSimulation

Sample Image Generation script

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Demos/StellarAttDet

Test a star sensor attitude determination system.
Test a star sensor attitude determination system with gyros.
Simulate a star sensor attitude determination system with gyros.
Demonstrate a Kalman Filter for a gyro based attitude determination system.
Demonstrate the Pinhole camera function
Demonstrate QFromU which performs static attitude determination.
Pyramid Star ID from a camera image
Test pyramid star identification with a random catalog

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Demos/UKF

A UKF that estimates thermal parameters for an isothermal model.
Estimate temperature and external flux using a UKF.
Demonstrate a fuel mass Kalman filter for a blowdown system.
UKF orbit angles

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EstimationData

1824_ers2_crd_20100719_20_00.frd2
Asteroid.jpgAsteroid image for centroiding.
GibbousMoon.jpgGibbous moon image for centroiding.

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OpticalNavigation

Compute the centroid for an asteroid
Selects landmark targets for an optical navigation system.
Selects planetary navigation targets for an optical navigation system.
Computes optical navigation accuracy.
Computes optical using lunar landmarks and stars.
Computes optical measurements for planets and stars.
Computes the noise matrix for navigation with stars and planets.
Computes three types of optical measurements.
Implements optical navigation using the Moon as a target
Compute the centroid for a planet
Find polar stars

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OrbitEstimation

Perform batch least-squares method for orbit determination.
Continuous discrete iterated Kalman Filter.
Cost function for image matching.
Computes the right-hand-side of the orbit equations for OrbitKalmanFilter.
Computes the right-hand-side of the for a point mass gravity model.
Generate the ECI coordinates of an Earth-fixed position at a given time
Generate the range/range rate measurement matrix and the estimated measurement.
Measurement matrix for range and range rate
Loads information from a CRD formatted file such as those used by the
Range rate to an Earth target.
Range and range rate to an Earth target.
Full state measurement of an orbit.
Computes the right-hand-side of the orbit equations about a mass point.
Generates a set of observations given an initial orbit state
Reshape a covariance matrix from square to a column and back.
Perform sequential batch least-squares method for orbit determination.
Demonstrate stellar navigation.

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RelativeState

Finds the transformation matrix and relative position given at least

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SensorMeas

Camera model which returns the centroid locations in the imaging plane.
Earth chord model for use with UKF.
GPS range and range rate model for use with UKF.
Nadir/star measurement for use with UKF.
3D radar model for use with Kalman Filters.
Range and range rate to ground station.
Outputs the set of acceptable attitude measurements from vectors.

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StarCentroiding

Group adjacent pixels together into blobs.
Center of mass centroiding algorithm.
Finds the centroids given a pixelmap.
Post process center-of-mass data
Load a star image and process it for centroids.
Finds stars in the field of view

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StarProcessing

APPLYTHRESHOLD Apply a threshold to a pixelmap
Calculate a histogram of the pixels and fit a Gaussian to the mode.
Fit a 2D gaussian to a star image
Fit a 2D Moffat PSF to a star image
Load a star image with imread and generate metadata.

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StarSimulation

Finds the output of each pixel through numerical integration.

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StarVisualization

Draw the blobs on top of the pixelmap using imagesc.
Draw a pixelmap using imagesc
Create a figure with two subplots, for the pixels and the centroids.
Plot the distribution of pixels values assuming integer bits.
PLOTCENTROIDS Plot star centroids on the image using pcolor
Generate a figure with two subplots of the histogram

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StellarAttDet

Remove known measurements and solved for measurement pairs.
Propagates a quaternion one step
Computes the pixel map conversion factor.
Convert pairs from the old format to the new format
Create the k vector from an array of data
Computes the discrete state transition matrix for a plant.
Computes the state transition matrix for the delta quaternion only.
Linearized star measurement function for in the UKF.
Nonlinear star measurement function for use in the UKF.
Propagates the quaternion assuming constant rate.
Finds the number of unique numbers in x and how many times they appear.
Default data structure for a pinhole camera.
Models a pinhole camera for star identification.
Finds the centroids of bright objects in the pixelMap.
Computes an attitude quaternion given a set of measured and cataloged
RHSGyro models a rate gyro or rate integrating gyro (RIG)
Quaternion derivative.
Computes angular rate from the equation mDot = m*Skew(w)
Reduction of stellar coordinates to apparent coordinates.
Quaternion state transition matrix
SEARCHKVECTOR Implement the range searching of data using a k vector.
Select a subset of measurements.
Make star ID snapshots and plot in a single figure.
Finds the centroid given intensities on n pixels and their coordinates.
Generates a star density plot.
STARIDPYRAMID Identifies the best star matches using triads.
Computes the measurement matrix, measurements and noise
Computes the measurements for the UKF
Make a star ID movie. Pass a cell array of starDataMeas arrays.
A stellar attitude determination system.
A stellar attitude determination system that does not use gyros.
Stellar attitude determination using the Unscented Kalman Filter

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StellarCatalog

Assess the global and local uniformity of a star catalog
Display a star catalog.
Models a pinhole camera. Projects the catalog into the camera frame.
Generates a star catalog for a patch of sky.
Converts intensity in watts/m^2 to apparent visual magnitude.
Load a catalog and reduce it based on visual magnitude.
Generates a text file with stars above the cutoff magnitude.
Load the Hipparcos catalog and create the near matrix
Generates a random star catalog in star matrix format.
Convert the catalog data structure to a structure array.
REDUCECATALOG Reduce the catalog based on the angular resolution.
Generates a star data structure from a star matrix.
Generates a star data structure
Generates a star catalog for testing the starid functions.
Create a sub catalog
Generates a swath catalog in star matrix format.
Computes the number of stars that are visible for a given aperture.
Converts apparent visual magnitude to electrons per second per mm^2.

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StellarData

FK5.txtFK4 data.
FK5Polar.matFK5 polar stars.
FK5Short.catFK5 short catalog.
FK5X.catFK5 based catalog.
Hipparcos.matHipparcos star catalog.
Plejades.tifSample star camera image
StarFieldDemo.jpgDemonstrate star field data.
StarPatch.matA star patch of polar stars from FK5.
dPTolData.datDot product tolerance data.
test.datTest data.

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StellarEphem

Compute the barycentric position and velocity of the earth.
Compute gravitational light deflection.
Converts a pixel location into a unit vector.
Convert right ascension and declination to pixels.
Determines if a unit vector falls within a square FOV
Adjust the vector u for aberration.
Compute the barycentric position of the sun.

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StellarModels

Computes the CCD noise structure.
Computes the angular resolution of the CCD.
Spread of a point light source due to defocusing
Simulates a spacecraft with rate integrating gyros.
Computes the output of a star sensor.
Finds the peak of the point spread function from visual magnitude.

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