GRDPostProcessOp.java

/*
 * Copyright (C) 2014 by Array Systems Computing Inc. http://www.array.ca
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 3 of the License, or (at your option)
 * any later version.
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see http://www.gnu.org/licenses/
 */
package org.esa.s1tbx.sentinel1.gpf;

import org.esa.snap.core.datamodel.Band;
import org.esa.snap.core.datamodel.MetadataElement;
import org.esa.snap.core.datamodel.Product;
import org.esa.snap.core.datamodel.VirtualBand;
import org.esa.snap.core.gpf.Operator;
import org.esa.snap.core.gpf.OperatorException;
import org.esa.snap.core.gpf.OperatorSpi;
import org.esa.snap.core.gpf.annotations.OperatorMetadata;
import org.esa.snap.core.gpf.annotations.SourceProduct;
import org.esa.snap.core.gpf.annotations.TargetProduct;
import org.esa.snap.core.util.ProductUtils;
import org.esa.snap.engine_utilities.datamodel.AbstractMetadata;
import org.esa.snap.engine_utilities.gpf.InputProductValidator;
import org.esa.snap.engine_utilities.gpf.OperatorUtils;

/**
 * Creates a new product with only selected bands
 */

@OperatorMetadata(alias = "GRD-Post",
        category = "Radar/Sentinel-1 TOPS",
        authors = "Jun Lu, Luis Veci",
        version = "1.0",
        copyright = "Copyright (C) 2014 by Array Systems Computing Inc.",
        description = "Applies GRD post-processing")
public final class GRDPostProcessOp extends Operator {

    @SourceProduct(alias = "source")
    private Product sourceProduct;
    @TargetProduct
    private Product targetProduct;

    /**
     * Initializes this operator and sets the one and only target product.
     * <p>The target product can be either defined by a field of type {@link Product} annotated with the
     * {@link TargetProduct TargetProduct} annotation or
     * by calling {@link #setTargetProduct} method.</p>
     * <p>The framework calls this method after it has created this operator.
     * Any client code that must be performed before computation of tile data
     * should be placed here.</p>
     *
     * @throws OperatorException If an error occurs during operator initialisation.
     * @see #getTargetProduct()
     */
    @Override
    public void initialize() throws OperatorException {

        try {
            final InputProductValidator validator = new InputProductValidator(sourceProduct);
            validator.checkIfSARProduct();
            validator.checkIfSentinel1Product();
            validator.checkProductType(new String[]{"SLC"});

            if(validator.isComplex()) {
                throw new OperatorException("Data should not be complex. Please first apply SLC to GRD processing.");
            }
            if(validator.isMultiSwath()) {
                throw new OperatorException("Data should not be in separate swaths. Please first apply SLC to GRD processing.");
            }

            String productName = sourceProduct.getName();
            productName = productName.replace("SLC_", "GRDH");

            targetProduct = new Product(productName, "GRD",
                    sourceProduct.getSceneRasterWidth(),
                    sourceProduct.getSceneRasterHeight());

            ProductUtils.copyProductNodes(sourceProduct, targetProduct);

            for (Band srcBand : sourceProduct.getBands()) {
                if (srcBand instanceof VirtualBand) {
                    ProductUtils.copyVirtualBand(targetProduct, (VirtualBand) srcBand, srcBand.getName());
                } else {
                    ProductUtils.copyBand(srcBand.getName(), sourceProduct, targetProduct, true);
                }
            }

            updateTargetProductMetadata();

        } catch (Throwable e) {
            OperatorUtils.catchOperatorException(getId(), e);
        }
    }

    /**
     * Update the metadata in the target product.
     */
    private void updateTargetProductMetadata() {

        final MetadataElement absRoot = AbstractMetadata.getAbstractedMetadata(targetProduct);

        String productName = absRoot.getAttributeString(AbstractMetadata.PRODUCT);
        absRoot.setAttributeString(AbstractMetadata.PRODUCT, productName.replace("SLC_", "GRDH"));
        String description = absRoot.getAttributeString(AbstractMetadata.SPH_DESCRIPTOR);
        absRoot.setAttributeString(AbstractMetadata.SPH_DESCRIPTOR, description.replace("SLC", "GRD"));
        absRoot.setAttributeString(AbstractMetadata.PRODUCT_TYPE, "GRD");
    }

    /**
     * The SPI is used to register this operator in the graph processing framework
     * via the SPI configuration file
     * {@code META-INF/services/org.esa.snap.core.gpf.OperatorSpi}.
     * This class may also serve as a factory for new operator instances.
     *
     * @see OperatorSpi#createOperator()
     * @see OperatorSpi#createOperator(java.util.Map, java.util.Map)
     */
    public static class Spi extends OperatorSpi {
        public Spi() {
            super(GRDPostProcessOp.class);
        }
    }
}