JP4020179B2

JP4020179B2 - Satellite-mounted imaging device

Info

Publication number: JP4020179B2
Application number: JP30663699A
Authority: JP
Inventors: 泰介遠藤
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1999-10-28
Filing date: 1999-10-28
Publication date: 2007-12-12
Anticipated expiration: 2019-10-28
Also published as: JP2001122199A

Description

【０００１】
【発明の属する技術分野】
この発明は、衛星に搭載し、地上を撮影する衛星搭載撮像装置に関するものである。
【０００２】
【従来の技術】
図４は従来の衛星搭載撮像装置を説明する図である。
図４において、４０は雲撮影用衛星、４１は雲撮影用衛星４０の撮影視野、４２は雲撮影用衛星４０の地上受信局、４３は地上撮像用衛星、４４は地上撮像用衛星４３の撮像視野、４５は地上撮像用衛星４３の地上局、４６は雲、４７は地上撮像用衛星４３の地上撮像視野４４の中心の軌跡である。
【０００３】
次に、従来の衛星搭載撮像装置の動作について説明する。
雲撮影用衛星４０により、撮影視野４１内の雲４６を撮影し、映像を地上受信局４２へ送り、地上受信局４２では、受信した映像をもとに、撮影した映像から撮影視野４１内の雲４６の分布を求める。地上撮像用衛星４３の地上局４５では、有効な地上撮像が出来るよう地上受信局４２から送られる雲４６の分布情報をもとに、地上撮像用衛星４３の撮像視野４４の中心の軌跡４７を求め、地上局４５から地上撮像用衛星４３の撮像視野４４を制御する。
【０００４】
【発明が解決しようとする課題】
従来の衛星搭載撮像装置では、雲撮影用衛星４０と地上撮像用衛星４３が別々であり、地上撮像用衛星４３の雲情報による運用は、雲撮影用衛星４０の撮影視野４１内に限定され、例えば、雲撮影用衛星４０が静止衛星で、地上撮像用衛星４３が静止衛星でない場合、雲情報を活用できる地域は静止衛星の撮像領域４１内に限定される。
【０００５】
また、雲撮影用衛星４０の撮影視野４１と地上撮像用衛星４３の撮像視野４４が相互に適切な大きさの関係にないと、撮像の機会を逃したり無効な撮像を行うことになる。例えば、雲撮影用衛星４０が静止衛星の場合、雲撮影用衛星４０の撮影視野４１は地上撮像用衛星４３の撮像視野４４より広くなることが多く、地上撮像用衛星４３の撮像視野４４と同程度の大きさの雲の間の晴れ間や、晴天の中の雲などがある場合、雲撮影用衛星４０からでは撮影視野４１が広すぎ、雲の間の晴れ間や晴天の中の雲などの検出ができず、撮像の機会を逃したり無効な撮像を行うことになる。
【０００６】
曇撮影用衛星４０が静止衛星でない場合には、雲撮影用衛星４０の撮影視野４１と地上撮像用衛星４３の撮像視野４４が相互に適切な大きさの関係に設定できるが、撮影時刻が異なると、雲の状況が雲検知から撮像までに変化し、より有効な撮像が出来ない。
【０００７】
この発明は上述した従来例に係る問題点を解消するためになされたもので、衛星進行方向前方の地上付近の雲状況を観測して撮像経路を選定することにより雲の影響を避けて地上を撮像することができる衛星搭載撮像装置を得ることを目的とするものである。
【０００８】
【課題を解決するための手段】
この発明に係る衛星搭載撮像装置は、雲による太陽光の反射光を受光する雲検出光学系と、上記雲検出光学系による受光光を電気信号に変換する検出器部と、上記検出器部の出力信号を増幅する増幅部と、上記増幅部の出力と雲量の関係を係数として予め記憶してなる雲量換算係数記憶装置と、上記雲量換算係数記憶装置に記憶された雲量換算係数と上記増幅部の出力に基づいて雲量を計算する雲量演算部と、上記雲検出光学系の指向方向を検出する指向方向検出器と、衛星の３次元位置を検出する衛星位置検出器と、上記指向方向検出器の出力と上記衛星位置検出器の出力とに基づいて上記雲検出光学系の視野である雲検出領域を算出する雲検出領域演算部と、地上設備から送信される位置荷重係数を受信する受信機と、上記受信機で受信した位置荷重係数を記憶する荷重係数記憶装置と、上記雲検出領域演算部の出力に基づき上記荷重係数記憶装置から荷重係数を読み出す荷重係数読出部と、上記荷重係数読出部から出力された上記荷重係数と上記雲量演算部から出力された上記雲量との積算に基づいて雲検出領域内の場所による観測の有効性の指標となる撮像評価係数を算出する撮像評価係数演算部と、複数の撮像経路の候補を記憶してなる撮像経路記憶装置と、上記撮像経路記憶装置に記憶された各撮像経路の候補と撮像評価係数から各撮像候補経路毎の評価値を求め相互比較して雲検出領域内での撮像経路を決定する相対撮像経路演算部と、上記相対撮像経路演算部で決定された曇検出領域に対する相対撮像経路を上記雲検出領域演算部の出力を用いて実空間の座標での撮像経路に変換する撮像経路演算部とで構成される撮像経路選定部を搭載したことを特徴とするものである。
【０００９】
また、地上を撮像する撮像光学系と、上記撮像経路選定部の出力により上記撮像光学系の指向方向を制御する撮像光学系指向駆動部と、上記撮像光学系の受光光を電気信号に変換するための画像検出器部と、上記画像検出器部の出力を増幅する画像増幅部と、上記画像増幅部から出力される画像信号を記録する画像記録部とで撮像部を構成し、上記撮像経路選定部の雲検出領域が上記撮像部の視野に対し相対的に衛星進行前方に位置するよう配置することを特徴とするものである。
さらに、雲による太陽光の反射光の反射データから雲量の分布を算出する雲量演算部と、雲検出領域を算出する雲検出領域演算部と、上記雲検出領域演算部で算出された雲検出領域内の位置に応じた位置荷重係数を受信し、当該位置荷重係数と上記雲量演算部で算出された雲量の分布状態との積算に基づいて、上記雲検出領域内の撮影経路毎に評価数値を算出する撮影評価係数演算部と、上記撮影評価係数演算部で算出された評価数値と上記雲検出領域演算部で算出された雲領域の位置とに基づいて、地上の撮影経路を決定する撮影経路演算部とを備えたことを特徴とするものである。
【００１０】
【発明の実施の形態】
実施の形態１．
以下、この発明の実施の形態１について図面を用いて詳細に説明する。
図１は、この発明の衛星搭載撮像装置を説明するための接続構成図である。
図１において、１は撮像経路選定部を示し、この撮像経路選定部１は、後述する符号２ないし１６に示す構成を有する。すなわち、雲検出領域を見る雲検出光学系２、雲検出光学系１の受光光を電気信号に変換する検出器部３、検出器部３の出力信号を増幅する増幅部４、検出器部４の出力レベルを雲量に換算するための換算係数を予め記憶しておく雲量換算係数記憶装置５、増幅部４の出力と雲量換算係数記憶装置５に記憶された係数から雲検出領域内の観測地域毎の雲量を算出する雲量演算部６、衛星の自己飛行位置を検出する衛星位置検出器７、雲検出光学系２の指向方向を検出する指向方向検出器８、衛星位置検出器７と指向方向偉出器８の出力から雲検出領域の位置座標を算出する雲検出領域演算部９を備える。
【００１１】
さらに、地上から送信される地上位置座標で標記され各観測地域毎に設定された荷重係数を受信する受信機１０、その荷重係数を記憶する荷重係数記憶装置１１、雲検出領域演算部９の出力により荷重係数記憶装置１１から各位置座標に対応する観測地域毎の荷重係数を読み出す荷重係数読出部１２、雲量演算部６による各観測地域毎の雲量とこの各観測地域に対応して荷重係数読出部１２から出力される各観測地域毎の荷重係数から各観測地域毎の撮像評価係数を算出する撮像評価係数演算部１３、雲観測領域内での複数の撮像経路候補を記憶する撮像経路記憶装置１４、撮像評価係数演算部１３の出力と撮像経路記憶装置１４に記憶された撮像経路候補から相対撮像経路を求める相対撮像経路演算部１５、相対撮像経路演算部１５の出力である相対撮像経路と雲検出領域演算部９の出力である雲検出領域の位置座標から実撮像経路を求める撮像経路演算部１６を備える。
【００１２】
また、１７は撮像部を示し、この撮像部１７は、地上を撮像する撮像光学系１８、撮像光学系１８の受光光を電気信号に変換する画像検出器部１９、画像検出器部１９の出力を増幅する画像増幅部２０、画像増幅部２０の出力を記録する画像記録部２１、撮像経路選定部１の出力により撮像光学系１８の指向方向を変化させる撮像光学系指向駆動部２２を備える。さらに、２３は上記撮像系路選定部１と上記撮像部１７を備える衛星搭載撮像装置、２４は地上設備、２５は太陽、２６は雲検知領域、２７は雲、２８は地上撮像領域である。
【００１３】
また、図２は、図１の雲量演算部６、撮像評価係数演算部１３及び相対撮像経路演算部１５の動作原理を説明する図である。
図２において、３０は図１の雲撮影領域２６の地上投影図、３１は地上投影図３０に投影された図１の雲２７の投影図、３２は地上投影図３０内の各観測地域毎に表記された雲量分布、３３は地上投影図３０に対応して図１の荷重係数読出部１２により各観測地域毎に読み出された荷重係数分布、３４は地上投影図３０に対応して図１の撮像評価係数演算部１３により各観測地位記毎に算出された撮像評価係数分布、３５は図１の撮像経路記憶装置１４に記憶された複数の撮像経路候補、３６はこれら撮像経路候補毎に各撮像経路に沿って撮像評価係数分布３５から算出した撮像評価値、３７は選択された撮像経路である。
【００１４】
さらに、図３は、図１の雲検出領域２６、撮像領域２８、図２の地上投影図３０、撮像経路３７の相互関係を示す図である。
【００１５】
次に動作について説明する。
図１において、雲検出領域２６内にある雲２７による太陽２５の反射光は、雲検出光学系２で受光され、その受光光は、検出器部３により電気信号に変換され、さらに、増幅部４により増幅される。雲量換算係数記憶装置５に予め記憶されている増幅部４の出力を雲量に換算するための換算係数と上記増幅部４の出力から雲検出領域内２６の雲量が計算される。この演算は、雲検出領域２６を構成する観測地域、例えば検出器部３を２次元ＣＣＤで構成する場合は、画素対応の領域毎に行われ、雲量演算部６の出力は雲量分布の形となる。
【００１６】
一方、地上設備２４から地上場影の重要度を場所毎の荷重係数として受信機１０に送信し、荷重係数は荷重係数記憶装置１１に記憶される。
【００１７】
衛星の３次元位置は衛星位置検出器７で検出され、雲検出光学系２の指向方向は指向方向検出器８で検出される。雲検出領域演算部９では、衛星位置検出器７の出力と指向方向検出器８の出力から光学系の視野である雲検出領域２６の地理的位置を算出する。荷重係数読出部１２では、雲検出領域２６に対応する地域の荷重係数を、荷重係数記憶装置１１に記憶されているデータから読み出す。読み出しは、雲検出領域２６内の各観測地域毎に行われ、出力は荷重係数分布の形となる。
【００１８】
上記雲量演算部６の出力と上記荷重係数読出部１２の出力は、対応する観測地域毎に撮像評価係数演算部１３で積算され、雲検知領域２６内の撮像評価係数分布が得られる。一例として、撮像評価係数としては、式（１）のような定義ができる。
撮像評価係数＝（１−雲量）×荷重係数（１）
【００１９】
撮像経路記憶装置１４には、雲検出領域２６内での実現可能な撮像経路の候補を予め複数種類記憶されており、相対撮像経路演算部１５では、撮像経路記憶装置１４に記憶された候補経路毎に経路に沿って各観測地域毎に上記撮像評価係数を積算し、各候補経路の評価係数の積算値を比較して最大になるものを相対撮像経路に設定する。相対経路とは雲撮像領域２６に対する相対的な経路であり、実空間の経路ではない。
【００２０】
撮像経路演算部１６では、相対撮像経路演算部１５の出力である相対撮像経路と雲検出領域演算部９の出力である雲検出領域２６の位置から実空間での撮像経路を算出する。
【００２１】
従って、上記撮像経路選定部１により、雲検知領域内の雲の分布状況と予め設定した地上の地域毎の撮影優先度もとに撮像評価値を算出して撮像経路候補から撮像経路を選定するので、雲の状況と撮像優先度を総合的に考慮した最適な撮像経路を選定できる。
【００２２】
一方、撮像部１７において、撮像光学系指向駆動部２２は、撮像経路演算部１６の出力により撮像光学系１８の指向方向を変化させる。これにより、撮像光学系１８の地上撮像領域２８は、撮像経路選定部１の選定結果に従い設定される。撮像光学系１８で受光した光は、画像検出器部１９で電気信号に変換され、画像増幅部２４で増幅され、画像記録部２１に記録される。
【００２３】
図２に示すように、地上投影図３０において、雲２７は、雲の投影図３１として現われる。雲検知領域全体を構成する各観測領域毎に雲量演算部６により雲量を求めると雲量分布３２が得られる。雲量分布３２と、図１の荷重係数読出部１２により各観測地域毎に読み出された荷重係数分布３３から図１の撮像評価係数演算部１３により地上投影図３０内の各観測地域毎に撮像評価係数を算出すると、撮像評価係数分布３４が得られる。
【００２４】
図１の撮像経路記憶装置１４に記憶された複数の撮像経路候補３５毎に各撮像経路に沿って撮像評価係数分布３４を積算すると、各撮像経路候補３５毎の撮像評価値３６が得られ、この撮像評価値を相互比較することにより撮像経路３７が選定できる。この例では、雲検知領域の地上投影図３０を５×５に分割しているが、一般的には、ｍ×ｎに分割でき、個々の領域の広さは地上撮像領域２８の大きさに対して調整可能である。また、撮像経路候補３５を衛星進行方向に平行直線としているが、斜め方向や曲線も設定可能である。
【００２５】
また、図３に示されるように、撮像装置２３には、撮像経路選定部１が搭載されており、撮像経路選定部１の雲検知領域２６の地上投影領域２８は、撮像装置２３に搭載される撮像部１７の地上撮像領域２８に対し、相対的に衛星進行方向前方に位置する。地上撮像領域２８は、衛星進行に伴い、撮像経路選定部１により選定された撮像経路３７に従い雲検知領域２６の地上投影領域２８を通過する。
【００２６】
従って、撮像経路選定部１の雲検出領域２６が撮像部１７の視野に対し相対的に衛星進行前方に位置し、撮像経路選定部１により選定した撮像経路に従い撮像光学系１８を指向するので、撮像予定領域の雲の状況を撮像直前に把握でき、撮像時の雲による遮蔽状況を精度よく予測でき、雲の影響と撮像優先度をともに考慮した撮像が可能となる。
【００２７】
【発明の効果】
以上のように、この発明によれば、雲検知領域内の雲の分布状況と予め設定した地上の地域毎の撮影優先度もとに撮像評価値を算出することにより撮像経路候補から撮像経路を選定する撮像経路選定部を有するので、雲の状況と撮像優先度を総合的に考慮した最適な撮像経路を選定でき、衛星進行方向前方の地上付近の雲状況を観測して撮像経路を選定することにより雲の影響を避けて地上を撮像することができる。
【００２８】
また、撮像経路選定部の雲検出領域が撮像部の視野に対し相対的に衛星進行前方に位置し、撮像経路選定部により選定した撮像経路に従い撮像光学系を指向するので、撮像予定領域の雲の状況を撮像直前に把握でき、撮像時の雲による遮蔽状況を精度よく予測でき、雲の影響と撮像優先度をともに考慮した撮像が可能となる。
【図面の簡単な説明】
【図１】この発明による衛星搭載撮像装置の系統構成図である。
【図２】この発明による衛星搭載撮像装置の動作原理の説明図である。
【図３】この発明による衛星搭載撮像装置の雲検知領域と撮像領域の関係を示す説明図である。
【図４】従来例による衛星搭載撮像装置の説明図である。
【符号の説明】
１撮像経路選定部、２雲検出光学系、３検出器部、４増幅部、５雲量換算係数記憶装置、６雲量演算部、７衛星位置検出器、８指向方向検出器、９雲検出領域演算部、１０受信器、１１荷重係数記憶装置、１２荷重係数読出部、１３撮像評価係数演算部、１４撮像経路記憶装置、１５相対撮像経路演算部、１６撮像経路演算部、１７撮像部、１８撮像光学系、１９画像検出器部、２０画像増幅部、２１画像記録部、２２撮像光学系指向駆動部、２３衛星搭載撮像装置、２４地上設備、２５太陽、２６雲検出領域、２７雲、２８地上撮像領域。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a satellite-mounted imaging device that is mounted on a satellite and images the ground.
[0002]
[Prior art]
FIG. 4 is a diagram for explaining a conventional satellite-mounted imaging device.
In FIG. 4, 40 is a cloud photographing satellite, 41 is a field of view of the cloud photographing satellite 40, 42 is a ground receiving station of the cloud photographing satellite 40, 43 is a ground imaging satellite, and 44 is a ground imaging satellite 43. The field of view, 45 is the ground station of the ground imaging satellite 43, 46 is a cloud, and 47 is the locus of the center of the ground imaging field of view 44 of the ground imaging satellite 43.
[0003]
Next, the operation of the conventional satellite-mounted imaging device will be described.
The cloud imaging satellite 40 captures a cloud 46 in the field of view 41 and sends the image to the ground receiving station 42. The ground receiving station 42 uses the received image to capture the image in the field of view 41. The distribution of the cloud 46 is obtained. In the ground station 45 of the ground imaging satellite 43, a locus 47 at the center of the imaging field 44 of the ground imaging satellite 43 is obtained based on the distribution information of the clouds 46 sent from the ground receiving station 42 so that effective ground imaging can be performed. Then, the imaging field 44 of the ground imaging satellite 43 is controlled from the ground station 45.
[0004]
[Problems to be solved by the invention]
In the conventional satellite-mounted imaging device, the cloud imaging satellite 40 and the ground imaging satellite 43 are separate, and the operation of the ground imaging satellite 43 based on cloud information is limited to the imaging field of view 41 of the cloud imaging satellite 40, For example, when the cloud photographing satellite 40 is a geostationary satellite and the ground imaging satellite 43 is not a geostationary satellite, the area where cloud information can be utilized is limited to the imaging area 41 of the geostationary satellite.
[0005]
Further, if the imaging field of view 41 of the cloud imaging satellite 40 and the imaging field of view 44 of the ground imaging satellite 43 are not in an appropriate size relationship, an imaging opportunity is missed or invalid imaging is performed. For example, when the cloud photographing satellite 40 is a geostationary satellite, the photographing field 41 of the cloud photographing satellite 40 is often wider than the imaging field 44 of the ground imaging satellite 43 and is the same as the imaging field 44 of the ground imaging satellite 43. When there is a clear sky between clouds of a certain size or clouds in a clear sky, the field of view 41 is too wide from the cloud photographing satellite 40, and a clear space between clouds or a cloud in a clear sky is detected. Therefore, the opportunity of imaging is missed or invalid imaging is performed.
[0006]
When the cloud photography satellite 40 is not a geostationary satellite, the imaging field of view 41 of the cloud photography satellite 40 and the imaging field of view 44 of the terrestrial imaging satellite 43 can be set to an appropriate size, but the photographing times are different. As a result, the cloud condition changes from cloud detection to imaging, and more effective imaging cannot be performed.
[0007]
The present invention was made to solve the above-described problems associated with the conventional example, and by observing the cloud condition near the ground in front of the satellite traveling direction and selecting the imaging route, the influence of the clouds can be avoided and the ground can be avoided. An object of the present invention is to obtain a satellite-mounted imaging device capable of imaging.
[0008]
[Means for Solving the Problems]
A satellite-mounted imaging device according to the present invention includes a cloud detection optical system that receives reflected light of sunlight from a cloud, a detector unit that converts light received by the cloud detection optical system into an electrical signal, and a detector unit that includes: An amplification unit that amplifies the output signal, a cloud conversion coefficient storage device that stores in advance the relationship between the output of the amplification unit and the cloud amount as a coefficient, a cloud conversion coefficient stored in the cloud conversion coefficient storage device, and the amplification unit A cloud amount calculation unit for calculating a cloud amount based on the output of the above, a pointing direction detector for detecting the pointing direction of the cloud detection optical system, a satellite position detector for detecting a three-dimensional position of the satellite, and the pointing direction detector A cloud detection area calculation unit that calculates a cloud detection area that is a field of view of the cloud detection optical system based on the output of the satellite and the output of the satellite position detector, and a receiver that receives a position load coefficient transmitted from the ground equipment And received by the above receiver And the load factor storage device for storing the position load factor, the load factor reading section for reading the load coefficient from the load coefficient storage device based on the output of the clouds detection area operation unit, the load output from the load coefficient reading unit An imaging evaluation coefficient calculation unit that calculates an imaging evaluation coefficient that serves as an indicator of the effectiveness of observation at a location in the cloud detection region based on the integration of the coefficient and the cloud amount output from the cloud amount calculation unit; and a plurality of imaging paths An imaging path storage device that stores the candidates, and an evaluation value for each imaging candidate path from the imaging path candidates stored in the imaging path storage device and the imaging evaluation coefficient, and compared with each other in the cloud detection region The relative imaging path calculation unit for determining the imaging path in the image and the relative imaging path for the cloud detection area determined by the relative imaging path calculation unit using the output of the cloud detection area calculation unit in the coordinates of the real space Is characterized in that mounting the configured imaging route selecting unit in the imaging path calculation section for converting the image path.
[0009]
Also, an imaging optical system that images the ground, an imaging optical system directivity driving unit that controls the directivity direction of the imaging optical system based on the output of the imaging path selection unit, and the light received by the imaging optical system is converted into an electrical signal. An image detector unit, an image amplifying unit that amplifies the output of the image detector unit, and an image recording unit that records an image signal output from the image amplifying unit. The cloud detection area of the selection unit is arranged so as to be positioned in front of the satellite traveling relative to the field of view of the imaging unit.
Further, a cloud amount calculation unit that calculates a cloud amount distribution from reflection data of sunlight reflected by the cloud, a cloud detection region calculation unit that calculates a cloud detection region, and a cloud detection region calculated by the cloud detection region calculation unit The position load coefficient corresponding to the position in the cloud is received, and based on the integration of the position load coefficient and the cloud amount distribution state calculated by the cloud amount calculation unit, an evaluation numerical value is obtained for each photographing path in the cloud detection region. A shooting path for determining a shooting path on the ground based on the shooting evaluation coefficient calculation unit to be calculated, the evaluation value calculated by the shooting evaluation coefficient calculation unit, and the position of the cloud area calculated by the cloud detection area calculation unit And an arithmetic unit.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a connection configuration diagram for explaining a satellite-mounted imaging device according to the present invention.
In FIG. 1, reference numeral 1 denotes an imaging path selection unit, and this imaging path selection unit 1 has a configuration indicated by reference numerals 2 to 16 described later. That is, the cloud detection optical system 2 for viewing the cloud detection region, the detector unit 3 for converting the received light of the cloud detection optical system 1 into an electrical signal, the amplification unit 4 for amplifying the output signal of the detector unit 3, and the detector unit 4 A cloud conversion coefficient storage device 5 that stores a conversion coefficient for converting the output level of the image into a cloud amount in advance, and an observation region in the cloud detection region from the output of the amplifying unit 4 and the coefficient stored in the cloud amount conversion coefficient storage device 5 Cloud amount calculation unit 6 for calculating the cloud amount for each, satellite position detector 7 for detecting the self-flight position of the satellite, pointing direction detector 8 for detecting the pointing direction of the cloud detection optical system 2, satellite position detector 7 and the pointing direction A cloud detection area calculation unit 9 is provided for calculating the position coordinates of the cloud detection area from the output of the prominent device 8.
[0011]
Furthermore, the receiver 10 that receives the load coefficient marked by the ground position coordinates transmitted from the ground and set for each observation area, the load coefficient storage device 11 that stores the load coefficient, and the output of the cloud detection area calculation unit 9 Thus, the load coefficient reading unit 12 that reads the load coefficient for each observation area corresponding to each position coordinate from the load coefficient storage device 11, the cloud amount for each observation area by the cloud amount calculation unit 6, and the load coefficient reading corresponding to each observation area An imaging evaluation coefficient computing unit 13 for calculating an imaging evaluation coefficient for each observation area from a load coefficient for each observation area output from the unit 12, and an imaging path storage device for storing a plurality of imaging path candidates in the cloud observation area 14. Output of the relative imaging path calculation unit 15 and the relative imaging path calculation unit 15 for obtaining a relative imaging path from the output of the imaging evaluation coefficient calculation unit 13 and the imaging path candidates stored in the imaging path storage device 14. An imaging route calculation unit 16 from a certain relative imaging path and the position coordinates of the cloud detection region which is the output of the cloud detection region calculation unit 9 obtains the actual imaging path.
[0012]
Reference numeral 17 denotes an imaging unit. The imaging unit 17 is an imaging optical system 18 that images the ground, an image detector unit 19 that converts received light of the imaging optical system 18 into an electrical signal, and an output of the image detector unit 19. An image amplifying unit 20 for amplifying the image, an image recording unit 21 for recording the output of the image amplifying unit 20, and an imaging optical system directivity driving unit 22 for changing the directing direction of the imaging optical system 18 by the output of the imaging path selecting unit 1. Further, reference numeral 23 denotes a satellite-mounted imaging device including the imaging path selection unit 1 and the imaging unit 17, 24 denotes ground equipment, 25 denotes the sun, 26 denotes a cloud detection area, 27 denotes a cloud, and 28 denotes a ground imaging area.
[0013]
FIG. 2 is a diagram for explaining the operation principle of the cloud amount calculation unit 6, the imaging evaluation coefficient calculation unit 13, and the relative imaging path calculation unit 15 of FIG.
In FIG. 2, 30 is a ground projection of the cloud photographing region 26 of FIG. 1, 31 is a projection of the cloud 27 of FIG. 1 projected on the ground projection 30, and 32 is for each observation area in the ground projection 30. The indicated cloud amount distribution 33 is a load factor distribution read out for each observation area by the load factor reading unit 12 of FIG. 1 corresponding to the ground projection map 30, and 34 is a map corresponding to the ground projection map 30. The imaging evaluation coefficient distribution calculated for each observation position by the imaging evaluation coefficient calculation unit 13 in FIG. 5, 35 is a plurality of imaging path candidates stored in the imaging path storage device 14 in FIG. 1, and 36 is for each of these imaging path candidates. An imaging evaluation value 37 calculated from the imaging evaluation coefficient distribution 35 along each imaging path and 37 are selected imaging paths.
[0014]
Further, FIG. 3 is a diagram showing the interrelationship between the cloud detection area 26, the imaging area 28 of FIG. 1, the ground projection map 30 of FIG.
[0015]
Next, the operation will be described.
In FIG. 1, the reflected light of the sun 25 by the cloud 27 in the cloud detection region 26 is received by the cloud detection optical system 2, and the received light is converted into an electric signal by the detector unit 3, and further, the amplification unit 4 is amplified. The cloud amount in the cloud detection area 26 is calculated from the conversion coefficient for converting the output of the amplifying unit 4 stored in advance in the cloud amount conversion coefficient storage device 5 into the cloud amount and the output of the amplifying unit 4. This calculation is performed for each observation area constituting the cloud detection region 26, for example, when the detector unit 3 is configured by a two-dimensional CCD, and the output of the cloud amount calculation unit 6 is in the form of the cloud amount distribution. Become.
[0016]
On the other hand, the importance of the ground field shadow is transmitted from the ground facility 24 to the receiver 10 as a load coefficient for each place, and the load coefficient is stored in the load coefficient storage device 11.
[0017]
The three-dimensional position of the satellite is detected by the satellite position detector 7, and the pointing direction of the cloud detection optical system 2 is detected by the pointing direction detector 8. The cloud detection area calculation unit 9 calculates the geographical position of the cloud detection area 26 that is the visual field of the optical system from the output of the satellite position detector 7 and the output of the pointing direction detector 8. The load coefficient reading unit 12 reads the load coefficient of the area corresponding to the cloud detection area 26 from the data stored in the load coefficient storage device 11. Reading is performed for each observation region in the cloud detection region 26, and the output is in the form of a load coefficient distribution.
[0018]
The output of the cloud amount calculation unit 6 and the output of the load coefficient reading unit 12 are integrated by the imaging evaluation coefficient calculation unit 13 for each corresponding observation area, and an imaging evaluation coefficient distribution in the cloud detection region 26 is obtained. As an example, the imaging evaluation coefficient can be defined as in Expression (1).
Imaging evaluation coefficient = (1−cloud amount) × load coefficient (1)
[0019]
The imaging path storage device 14 stores a plurality of types of imaging path candidates that can be realized in the cloud detection area 26 in advance, and the relative imaging path calculation unit 15 stores candidate paths stored in the imaging path storage device 14. The imaging evaluation coefficients are integrated for each observation area along the path every time, and the integrated value of the evaluation coefficients of the candidate paths is compared and the one that maximizes is set as the relative imaging path. The relative path is a path relative to the cloud imaging region 26 and is not a path in real space.
[0020]
The imaging path calculation unit 16 calculates an imaging path in real space from the position of the relative imaging path that is the output of the relative imaging path calculation unit 15 and the cloud detection area 26 that is the output of the cloud detection area calculation unit 9.
[0021]
Therefore, the imaging route selection unit 1 calculates an imaging evaluation value based on the cloud distribution state in the cloud detection area and the imaging priority for each area on the ground, and selects an imaging route from the imaging route candidates. Therefore, it is possible to select an optimal imaging path that comprehensively considers the cloud status and imaging priority.
[0022]
On the other hand, in the imaging unit 17, the imaging optical system directivity driving unit 22 changes the directing direction of the imaging optical system 18 by the output of the imaging path calculation unit 16. Thereby, the ground imaging area 28 of the imaging optical system 18 is set according to the selection result of the imaging path selection unit 1. The light received by the imaging optical system 18 is converted into an electrical signal by the image detector unit 19, amplified by the image amplification unit 24, and recorded in the image recording unit 21.
[0023]
As shown in FIG. 2, in the ground projection map 30, the cloud 27 appears as a cloud projection map 31. When the cloud amount calculation unit 6 obtains the cloud amount for each observation region constituting the entire cloud detection region, a cloud amount distribution 32 is obtained. Imaging is performed for each observation region in the ground projection map 30 by the imaging evaluation coefficient calculation unit 13 from the cloud distribution 32 and the load coefficient distribution 33 read for each observation region by the load factor reading unit 12 of FIG. When the evaluation coefficient is calculated, an imaging evaluation coefficient distribution 34 is obtained.
[0024]
When the imaging evaluation coefficient distribution 34 is accumulated along each imaging path for each of the plurality of imaging path candidates 35 stored in the imaging path storage device 14 of FIG. 1, an imaging evaluation value 36 for each imaging path candidate 35 is obtained. The imaging path 37 can be selected by comparing the imaging evaluation values with each other. In this example, the ground projection map 30 of the cloud detection area is divided into 5 × 5, but in general, it can be divided into m × n, and the size of each area is the size of the ground imaging area 28. It can be adjusted. Further, although the imaging path candidate 35 is a straight line parallel to the satellite traveling direction, an oblique direction or a curved line can be set.
[0025]
As shown in FIG. 3, the imaging device 23 is equipped with the imaging route selection unit 1, and the ground projection area 28 of the cloud detection region 26 of the imaging route selection unit 1 is installed in the imaging device 23. The image capturing unit 17 is positioned in front of the ground image capturing area 28 in the satellite traveling direction. The ground imaging area 28 passes through the ground projection area 28 of the cloud detection area 26 according to the imaging path 37 selected by the imaging path selection unit 1 as the satellite travels.
[0026]
Accordingly, the cloud detection area 26 of the imaging path selection unit 1 is positioned in front of the satellite traveling relative to the field of view of the imaging unit 17, and is directed to the imaging optical system 18 according to the imaging path selected by the imaging path selection unit 1. The situation of the cloud in the scheduled imaging area can be grasped immediately before imaging, the shielding situation by the cloud at the time of imaging can be accurately predicted, and imaging taking into consideration both the influence of the cloud and the imaging priority can be performed.
[0027]
【The invention's effect】
As described above, according to the present invention, the imaging route is calculated from the imaging route candidate by calculating the imaging evaluation value based on the distribution state of the clouds in the cloud detection region and the imaging priority for each ground area set in advance. Since it has an imaging path selection unit to select, it is possible to select the optimal imaging path that comprehensively considers the cloud status and imaging priority, and selects the imaging path by observing the cloud situation near the ground in front of the satellite traveling direction Therefore, the ground can be imaged while avoiding the influence of clouds.
[0028]
In addition, the cloud detection area of the imaging path selection unit is positioned in front of the satellite relative to the field of view of the imaging unit, and is directed to the imaging optical system according to the imaging path selected by the imaging path selection unit. Can be grasped immediately before imaging, and the shielding situation by clouds at the time of imaging can be accurately predicted, and imaging taking into consideration both the influence of clouds and imaging priority can be performed.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a satellite-mounted imaging device according to the present invention.
FIG. 2 is an explanatory diagram of an operation principle of the satellite-mounted imaging device according to the present invention.
FIG. 3 is an explanatory diagram showing a relationship between a cloud detection area and an imaging area of the satellite-mounted imaging apparatus according to the present invention.
FIG. 4 is an explanatory diagram of a satellite-mounted imaging device according to a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Imaging route selection part, 2 Cloud detection optical system, 3 Detector part, 4 Amplification part, 5 Cloud amount conversion coefficient memory | storage device, 6 Cloud amount calculation part, 7 Satellite position detector, 8 Directional direction detector, 9 Cloud detection area calculation , 10 receiver, 11 load coefficient storage device, 12 load coefficient reading unit, 13 imaging evaluation coefficient calculation unit, 14 imaging path storage device, 15 relative imaging path calculation unit, 16 imaging path calculation unit, 17 imaging unit, 18 imaging Optical system, 19 Image detector section, 20 Image amplification section, 21 Image recording section, 22 Imaging optical system pointing drive section, 23 Satellite-mounted imaging device, 24 Ground equipment, 25 Sun, 26 Cloud detection area, 27 Cloud, 28 Ground Imaging area.

Claims

A cloud detection optical system that receives reflected light of sunlight from the clouds;
A detector for converting light received by the cloud detection optical system into an electrical signal;
An amplifying unit for amplifying the output signal of the detector unit;
A cloud amount conversion coefficient storage device that stores in advance the relationship between the output of the amplifying unit and the cloud amount as a coefficient;
A cloud amount calculation unit that calculates a cloud amount based on the cloud amount conversion coefficient stored in the cloud amount conversion coefficient storage device and the output of the amplifying unit;
A pointing direction detector for detecting the pointing direction of the cloud detection optical system;
A satellite position detector for detecting the three-dimensional position of the satellite;
A cloud detection region calculation unit that calculates a cloud detection region that is a field of view of the cloud detection optical system based on the output of the pointing direction detector and the output of the satellite position detector;
A receiver for receiving a position load coefficient transmitted from the ground facility;
A load coefficient storage device for storing the position load coefficient received by the receiver;
A load coefficient reading unit that reads a load coefficient from the load coefficient storage device based on an output of the cloud detection region calculation unit;
Based on the integration of the load coefficient output from the load coefficient reading unit and the cloud amount output from the cloud amount calculation unit, an imaging evaluation coefficient serving as an index of the effectiveness of observation by a place in the cloud detection region is calculated. An imaging evaluation coefficient calculation unit;
An imaging path storage device that stores a plurality of imaging path candidates;
A relative imaging path calculation unit that determines an imaging path in the cloud detection region by obtaining an evaluation value for each imaging candidate path from the imaging path candidates stored in the imaging path storage device and an imaging evaluation coefficient, and comparing the evaluation values; ,
An imaging path calculation unit configured to convert a relative imaging path with respect to the cloud detection area determined by the relative imaging path calculation unit to an imaging path in real space coordinates using an output of the cloud detection area calculation unit. A satellite-mounted image pickup device equipped with a route selection unit.

The satellite-borne imaging device according to claim 1,
An imaging optical system for imaging the ground;
An imaging optical system directional drive unit that controls a directional direction of the imaging optical system according to an output of the imaging path selection unit;
An image detector unit for converting received light of the imaging optical system into an electrical signal;
An image amplifying unit for amplifying the output of the image detector unit;
An image recording unit that records an image signal output from the image amplification unit constitutes an imaging unit, and the cloud detection area of the imaging path selection unit is positioned in front of the satellite traveling relative to the field of view of the imaging unit A satellite-mounted imaging device characterized by being arranged as described above.

A cloud amount calculation unit for calculating a cloud amount distribution from reflection data of sunlight reflected by the cloud;
A cloud detection area calculation unit for calculating a cloud detection area;
The position load coefficient corresponding to the position in the cloud detection region calculated by the cloud detection region calculation unit is received, and based on the integration of the position load coefficient and the cloud amount distribution state calculated by the cloud amount calculation unit, A shooting evaluation coefficient calculation unit that calculates an evaluation value for each shooting path in the cloud detection region;
A shooting path calculation unit that determines a shooting path on the ground based on the evaluation value calculated by the shooting evaluation coefficient calculation unit and the position of the cloud area calculated by the cloud detection area calculation unit. A satellite-mounted imaging device.