OutlierFilter.java
- /* Copyright 2002-2022 CS GROUP
- * Licensed to CS GROUP (CS) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * CS licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- package org.orekit.estimation.measurements.modifiers;
- import java.util.Collections;
- import java.util.List;
- import org.hipparchus.util.FastMath;
- import org.orekit.estimation.measurements.EstimatedMeasurement;
- import org.orekit.estimation.measurements.EstimationModifier;
- import org.orekit.estimation.measurements.ObservedMeasurement;
- import org.orekit.utils.ParameterDriver;
- /** Modifier that sets estimated measurement weight to 0 if residual is too far from expected domain.
- * @param <T> the type of the measurement
- * @author Luc Maisonobe
- * @since 8.0
- */
- public class OutlierFilter<T extends ObservedMeasurement<T>> implements EstimationModifier<T> {
- /** Warmup iterations. */
- private final int warmup;
- /** Outlier detection limit. */
- private final double maxSigma;
- /** Simple constructor.
- * @param warmup number of iterations before with filter is not applied
- * @param maxSigma detection limit for outliers.
- */
- public OutlierFilter(final int warmup, final double maxSigma) {
- this.warmup = warmup;
- this.maxSigma = maxSigma;
- }
- /** Get the value of warmup iterations.
- * @return the value of warmup iterations
- */
- protected int getWarmup() {
- return warmup;
- }
- /** Get the value of the outlier detection limit.
- * @return the value of the outlier detection limit
- */
- protected double getMaxSigma() {
- return maxSigma;
- }
- /** {@inheritDoc} */
- @Override
- public List<ParameterDriver> getParametersDrivers() {
- return Collections.emptyList();
- }
- /** {@inheritDoc} */
- @Override
- public void modify(final EstimatedMeasurement<T> estimated) {
- if (estimated.getIteration() > warmup) {
- // check if observed value is far to estimation
- final double[] observed = estimated.getObservedMeasurement().getObservedValue();
- final double[] theoretical = estimated.getEstimatedValue();
- final double[] sigma = estimated.getObservedMeasurement().getTheoreticalStandardDeviation();
- for (int i = 0; i < observed.length; ++i) {
- if (FastMath.abs(observed[i] - theoretical[i]) > maxSigma * sigma[i]) {
- // observed value is too far, reject measurement
- estimated.setStatus(EstimatedMeasurement.Status.REJECTED);
- }
- }
- }
- }
- }