Sensor deployment problem for target location estimation is important for sensor networks which fulfill the monitoring tasks. In this paper, we investigate the deployment schemes which guarantee the location estimation accuracy of an arbitrary point within the region, by connecting the location estimation problem with the perspective of k-coverage problem. Our strategies are deploying sensors to guarantee the location-estimation accuracy of an arbitrary point within the monitored region, and to minimize the number of required sensors. Compared with the random deployment, the deterministic deployment provides a better solution to guarantee the location-estimation accuracy over the monitored region. Regular space deployment patterns in 2-dimension, i.e. equilateral triangle, square and regular hexagon, are discussed. The relationship between deployment density and vacancy ratio are derived by mathematical analysis. The derived required sensors deployment density to an arbitrary vacancy ratio for location-estimation coverage provides useful guidelines for sensor network deployment when location-estimation system is required for any practical application.