农业监测应用数据评价

1999年成功发射的地球观测系统的第1个卫星Terra上搭载着先进星载热辐射与反射测量仪ASTER，其数据在可见光、近红外区的3个波段的空间分辨率为15m，具有与Landsat7 ETM数据相似的波段特征。由于ASTER数据价格低廉，将可能广泛应用于农业监测。该文以ETM融合图像为基准，从几何纠正精度、典型地物识别、地物面积量测、影像分类解译4个关键环节对ASTER数据进行了校验。结果表明，ASTER数据可以实现高精度的几何纠正，图像质量优于ETM融合图像，ASTER数据能够表达细小地物的纹理细节，更适合于地物的目视识别，ASTER图像内部几何畸变较小或较一致，量算地物面积准确，ASTER数据分类解译具有与ETM一样的效果，精度较高，是农业监测的又一个重要数据源。

Data assessment for agricultural monitoring applications

The first Earth Observing System(EOS) satellite called Terra was launched in 1999. ASTER is one of the five state-of-the-art instrument sensor systems on-board Terra with 3 bands of 15m spatial resolution in the visible near-infrared wavelength regions. These three bands have the same spectral zones as Landsat7 ETM. ASTER data will be more and more used to monitoring agriculture for low price in the future. This paper tests the performance of ASTER data in the aspects of geometric correction, typical surface features identification, land target area measurement, image classification and interpretation, taking ETM merged image with pan band and multispectral bands as reference. The results show that ASTER image can be geometrically corrected with high accuracy, and it is better than ETM merged image. ASTER image records the small land targets in detail, which can be more suitable for recognition by eyes, and can be used for measuring land targets area with high accuracy. It has the same good performance as ETM image for image classification and interpretation. In a word, ASTER will be a newer and more important data source for agricultural monitoring applications.