initial state of coordinateTranslation has the Y axis inverted.

main.cpp

#pragma once

#include <osgViewer\Viewer>
#include <osgEarthDrivers\gdal\GDALOptions>
#include <osgEarth\ImageLayer>
#include <osgEarth\MapNode>
#include <osgEarthUtil\EarthManipulator>
#include <iostream>
#include <osg\ShapeDrawable>

public class PointInCenterScreen : public osg::Operation {
public:
#define RADIUS 10000

  PointInCenterScreen(osgViewer::Viewer* viewer,
    osgEarth::Util::EarthManipulator* manipulator) {
    setKeep(true);

    _viewer = viewer;
    _manipulator = manipulator;

    _box = new osg::Box(osg::Vec3d(), RADIUS);
    _drawable = new osg::ShapeDrawable(_box);
    _drawable->setColor(osg::Vec4(0.0, 1.0, 0.0, 1.0));
    osg::Group* root = reinterpret_cast<osg::Group*>(viewer->getSceneData());
    root->addChild(_drawable);
  }

  virtual void operator()(osg::Object *object) {
    osg::Viewport* vp = _viewer->getCamera()->getViewport();
    osg::Vec3d world;
    _manipulator->screenToWorld(vp->width() / 2.0, vp->height() / 2.0, _viewer->getCamera()->getView(), world);
    _box->setCenter(world);
    _drawable->dirtyDisplayList();
    _drawable->dirtyBound();
    if (_viewer->getFrameStamp()->getFrameNumber() % 60 == 0) {
      osg::Vec3d geo;
      _manipulator->getViewpoint().focalPoint()->getSRS()->transformFromWorld(world, geo);
      std::cout << geo.x() << "," << geo.y() << "," << geo.z() << std::endl;
    }
  }

  osgViewer::Viewer* _viewer;
  osgEarth::Util::EarthManipulator* _manipulator;
  osg::ShapeDrawable* _drawable;
  osg::Box* _box;
};

int main() {
  osgViewer::Viewer* viewer =  new osgViewer::Viewer;
  viewer->setUpViewInWindow(100, 100, 1000, 1000, 0);
  osg::ref_ptr<osgEarth::MapNode> mapNode = new osgEarth::MapNode;
  viewer->setSceneData(mapNode.get());

  osgEarth::Drivers::GDALOptions gdalOptions;
  gdalOptions.url() = osgEarth::URI("world.tif");
  gdalOptions.extensions() = "tif";

  mapNode->getMap()->addImageLayer(new osgEarth::ImageLayer(gdalOptions));

  osgEarth::Util::EarthManipulator* manip = new osgEarth::Util::EarthManipulator;
  viewer->setCameraManipulator(manip);

  manip->setViewpoint(osgEarth::Viewpoint("", 74.0, 42.0, 0.0, 0.0, -90.0, 1000000));

  osg::Operation* update = new ::PointInCenterScreen(viewer, manip);

  viewer->addUpdateOperation(update);

  viewer->run();
}