character height 3 times higher than expected

public class Extractor extends PDFTextStripper {
//<...CUT...>
	protected void writePage() throws IOException {
		for (List<TextPosition> textList : charactersByArticle) { //charactersByArticle was inherited from base class
			Iterator textIter = textList.iterator();
//<...CUT...>
			while (textIter.hasNext()) {
				TextPosition position = (TextPosition) textIter.next();
//<...CUT...>
		PDFontDescriptor fontDescriptor = position.getFont().getFontDescriptor();
//<...CUT...>

		float yscale = position.getTextPos().getYScale();
		float asc = Math.abs(fontDescriptor.getAscent() / 1000 * yscale);
		float rh = Math.abs(fontDescriptor.getFontBoundingBox().getUpperRightY() / 1000 * yscale);

		float desc = Math.abs(fontDescriptor.getDescent() / 1000 * yscale);
		float capHeight = Math.abs(fontDescriptor.getCapHeight() / 1000 * yscale);
		if (capHeight == 0)
			capHeight = position.getHeight();

		float h = (rh + Math.max(Math.max(capHeight, position.getHeight()), asc)) / 2;

//"h" evaluates to 37.39 (should be between 11 and 12)
//"desc" evaluates to 2.664
//"capHeight" evaluates to 37.39
//"position.getHeight()" evaluates to 33.48