中国光学
中國光學
중국광학
CHINESE JOURNAL OF OPTICS
2013年
5期
750-758
,共9页
宽覆盖相机%光学遥感相机%侧摆%像移速度%调制传递函数
寬覆蓋相機%光學遙感相機%側襬%像移速度%調製傳遞函數
관복개상궤%광학요감상궤%측파%상이속도%조제전체함수
wide coverage camera%optical remote camera%scroll%image motion velocity%Modulation Transfer Function(MTF)
根据宽覆盖相机的特性,分析了其侧摆成像的几何关系。建立了地面物点到相机像面的空间坐标变换关系,在此基础上,推导了基于圆地球模型的相机侧摆像移速度计算公式,并以像移失配传递函数MTFmismatch作为评价方法分析了相对像移匹配残差对像质的影响。以某宽覆盖型相机为例,计算了不同侧摆角和不同地心角条件下的像面像移速度。计算结果表明:像面各点的侧摆像移速度均不相同,且变化趋势也不相同,远地点处像移速度相对变化量最大。在侧摆角为25°且积分级数为48的条件下,像移失配传递函数的最大值为0.681。外场成像试验结果表明,积分级数控制在16级以内时的相机成像质量良好。
根據寬覆蓋相機的特性,分析瞭其側襬成像的幾何關繫。建立瞭地麵物點到相機像麵的空間坐標變換關繫,在此基礎上,推導瞭基于圓地毬模型的相機側襬像移速度計算公式,併以像移失配傳遞函數MTFmismatch作為評價方法分析瞭相對像移匹配殘差對像質的影響。以某寬覆蓋型相機為例,計算瞭不同側襬角和不同地心角條件下的像麵像移速度。計算結果錶明:像麵各點的側襬像移速度均不相同,且變化趨勢也不相同,遠地點處像移速度相對變化量最大。在側襬角為25°且積分級數為48的條件下,像移失配傳遞函數的最大值為0.681。外場成像試驗結果錶明,積分級數控製在16級以內時的相機成像質量良好。
근거관복개상궤적특성,분석료기측파성상적궤하관계。건립료지면물점도상궤상면적공간좌표변환관계,재차기출상,추도료기우원지구모형적상궤측파상이속도계산공식,병이상이실배전체함수MTFmismatch작위평개방법분석료상대상이필배잔차대상질적영향。이모관복개형상궤위례,계산료불동측파각화불동지심각조건하적상면상이속도。계산결과표명:상면각점적측파상이속도균불상동,차변화추세야불상동,원지점처상이속도상대변화량최대。재측파각위25°차적분급수위48적조건하,상이실배전체함수적최대치위0.681。외장성상시험결과표명,적분급수공제재16급이내시적상궤성상질량량호。
According to the feature of a wide coverage space camera , the geometrical relation of scroll imaging was analyzed .The space coordinate transform process from an object point on the earth to the image point in the focal plane was found.Furthermore, the calculation formulas of scroll image motion velocity were deduced based on a round earth model by using the transform of space coordinate system .The effect of relative image motion match error on the image quality was analyzed by the image motion mismatch modulation transfer func-tion(MTFmismatch ).By taking a wide coverage space camera for an example , image motion velocities at different scroll angles and different centrifugal angles were researched .Computation results indicate that the image mo-tion velocities and their variation trends with the scroll angle are different in the different positions of image plane.The MTFmismatch caused by mismatch image motion velocity reaches 0.681 at the perigee if the scroll an-gle is 25°and the TDI stage is 48.The actual field experimental results show that it is necessary to keep the TDI stages within 16 to ensure good image quality.