基于ENVI二次开发的高光谱推扫图像拼接技术

Technology of hyperspectral push broom image mosaicking based on ENVI redevelopment

针对推扫式成像光谱仪获取的狭带影像需要经过几何校正才能拼接形成空间二维影像的问题,提出了基于ENVI二次开发的高光谱推扫图像拼接技术。基于单应映射建立光谱仪倾斜状态下与正射状态下图像上的二维点之间的关系,校正由姿态变化引起的图像畸变;结合GPS数据修正因飞行速度变化引起的狭带重叠,将校正后的狭带影像拼接起来;在ENVI二次开发平台上进行技术集成,实现了推扫高光谱狭带影像的自动校正拼接。对河北保定郊区高光谱影像的校正拼接实验证明,该方法与光谱仪自带拼接软件校正结果接近,经纬度坐标差均在1 m以内,均方根误差约为0.738 9,能够满足一般高光谱遥感应用中的地理精度要求。

As the narrow stripes obtained by the push-broom imaging spectrometer need to be geometrically corrected before mosaicking into a spatial two-dimensional image,a technique of hyperspectral push-broom image mosaicking based on ENVI redevelopment was proposed in this paper. A relationship of points on the images between tilting state and orthographic state of the spectrometer was established based on homography mapping,and image distortion caused by the variation of flight posture was corrected. GPS data was combined to correct the stripe overlap due to the change of flight speed and the corrected stripes were mosaicked together. Technical integration was carried out on the ENVI redevelopment platform,realizing the automatic calibration and mosaicking of hyperspectral push broom stripes. Experiments were carried out in Baoding suburbs of Hebei province,and it showed that the mosaicking result obtained by proposed method was close to that obtained by spectrometer software. The coordinate differences of latitude and longitude were bothwithin 1 m,and the root mean square error was about 0. 738 9,which could meet the geographical accuracy requirements of general hyperspectral remote sensing application.