Laser land levelling has contributed immensely to irrigation water saving to cope with declining ground water tables in South Asia. A topographic survey of a field is a pre-requisite to achieve high accuracy in land levelling. Presently, manual topographic surveys are conducted before using a laser land leveller in South Asia, which is cumbersome, time consuming and requires substantial operator skill. A novel sensor-based automatic topographic survey is potentially more precise and cost-effective. Therefore, a field study was conducted to compare the efficiency of a tractor operated sensor-based automatic survey system attached to a laser leveller compared with the conventional manual topographic survey. The automatic survey system consisted of automatic functioning of the laser operated power mast and scraper. The automatic survey method significantly reduced the earthwork and levelness index by 74.0 and 75.4% compared with 61.5 and 62.1% for manual topographic survey, respectively. The automatic survey improved the land uniformity coefficient by 78.4% compared with 42.4% for the manual survey. Average fuel consumption and field capacity were 56.5% and 48% higher for automatic survey compared to manual topographic survey method. The average survey cost was 38.2% lower for automatic survey compared with manual survey. The field capacity of the laser leveller (including the time taken for field survey) was significantly higher by 53% for automatic survey than manual survey. The total cost of operation of automatic survey method was 30.1% lower compared with conventional manual survey. Based on the results from this study, the newly developed automatic survey system is superior to conventional manual survey method in terms of precision in land levelling and economic gains.

中文翻译：

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用于精密土地平整的自动相对于手动地形测量的性能评估

激光土地平整为应对南亚地下水位下降的灌溉节水做出了巨大贡献。田地的地形测量是实现高精度土地平整的先决条件。目前，在南亚使用激光平整机之前，需要先进行手动地形测量，这既麻烦又耗时，并且需要大量的操作员技能。一种新型的基于传感器的自动地形测量可能更精确和更具成本效益。因此，进行了一项实地研究，以比较连接到激光矫平机的拖拉机操作的基于传感器的自动测量系统与传统手动地形测量的效率。自动测量系统由激光操作的动力桅杆和刮刀的自动功能组成。与手动地形测量的61.5和62.1%相比，自动测量方法显着降低了土方工程和水平度指数74.0和75.4%。与人工调查的42.4%相比，自动调查将土地均匀性系数提高了78.4%。与手动地形测量方法相比，自动测量的平均燃料消耗和现场容量分别高出 56.5% 和 48%。与人工调查相比，自动调查的平均调查成本降低了 38.2%。激光整平机的现场容量（包括现场勘察所用的时间）在自动勘察中比手动勘察高出 53%。与传统人工调查相比，自动调查方法的总运行成本降低了30.1%。根据这项研究的结果，