coverage_string.push_back(SGCloudLayer::SG_CLOUD_CLEAR_STRING);
coverage_string.push_back(SGCloudLayer::SG_CLOUD_FEW_STRING);
coverage_string.push_back(SGCloudLayer::SG_CLOUD_SCATTERED_STRING);
coverage_string.push_back(SGCloudLayer::SG_CLOUD_CLEAR_STRING);
coverage_string.push_back(SGCloudLayer::SG_CLOUD_FEW_STRING);
coverage_string.push_back(SGCloudLayer::SG_CLOUD_SCATTERED_STRING);