JPS6237345B2 - - Google Patents
Info
- Publication number
- JPS6237345B2 JPS6237345B2 JP54009828A JP982879A JPS6237345B2 JP S6237345 B2 JPS6237345 B2 JP S6237345B2 JP 54009828 A JP54009828 A JP 54009828A JP 982879 A JP982879 A JP 982879A JP S6237345 B2 JPS6237345 B2 JP S6237345B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- noise source
- switch
- output
- noise
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/006—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using measurement of the effect of a material on microwaves or longer electromagnetic waves, e.g. measuring temperature via microwaves emitted by the object
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Radiation Pyrometers (AREA)
- Geophysics And Detection Of Objects (AREA)
Description
【発明の詳細な説明】
この発明は、人工衛星等の飛翔体に搭載してリ
モートセンシングを行うマイクロ波放射計のアン
テナ温度校正用低雑音源の改良に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a low noise source for calibrating the antenna temperature of a microwave radiometer that is mounted on a flying object such as an artificial satellite and performs remote sensing.
第１図は従来の人工衛星に搭載して地球表面の
物体から放射する電磁波を受信して地球環境のリ
モートセンシングを行うマイクロ波放射計の一例
である。図中、１は受信アンテナ、２はスカイホ
ーンと呼ばれるホーンアンテナ、３は標準雑音
源、４は比較雑音源、５は受信機および６，７，
８はそれぞれスイツチＡ，Ｂ，Ｃである。一般に
自然界の物体からは電磁波が放射されており、放
射の強度はその物体の輝度温度と密接な関係があ
る。第１図の受信アンテナ１で受信されるアンテ
ナ温度ＴAは受信アンテナ１を取りまく物体の輝
度温度の分布ＴB（Ω）と受信アンテナ１の利得
関数Ｇ（Ω）とを用いて
ＴA＝１／４π∫∫4〓Ｇ（Ω）ＴB（Ω）ｄΩ……(1)
で表される。ここでΩは立体角である。 FIG. 1 is an example of a conventional microwave radiometer mounted on an artificial satellite to receive electromagnetic waves emitted from objects on the earth's surface and perform remote sensing of the earth's environment. In the figure, 1 is a receiving antenna, 2 is a horn antenna called a skyhorn, 3 is a standard noise source, 4 is a comparison noise source, 5 is a receiver, and 6, 7,
8 are switches A, B, and C, respectively. Generally, objects in the natural world emit electromagnetic waves, and the intensity of the radiation is closely related to the brightness temperature of the object. The antenna temperature T A received by the receiving antenna 1 in FIG . It is expressed as 1/4π∫∫ 4 〓G(Ω)T B (Ω)dΩ……(1). Here Ω is the solid angle.
スイツチＡ６が側に接続されている場合、受
信されたアンテナ温度ＴAはスイツチＢ７に向か
う。スイツチＢ７はある瞬間には側に接続さ
れ、次の瞬間には側に接続される操作を数百Hz
で繰り返す。またスイツチＢ７の側には比較的
高温で一定温度T0の雑音を発生する比較雑音源
４が接続されており、このスイツチ切換操作に同
期する受信機５内の同期検波器を通して比較雑音
源４の温度T0とアンテナ温度ＴAとの差に比例す
る電圧Ｖが得られる。マイクロ波放射計の観測機
能を達成するためには、発生した電圧Ｖをもとに
アンテナ温度ＴAの値を知ることが必要条件であ
り、この値は次の手順を経ることによつて求める
ことができる。 If switch A6 is connected to the side, the received antenna temperature T A goes to switch B7. Switch B7 is connected to the side at one moment, and the operation at the next moment is several hundred Hz.
Repeat with Further, a comparison noise source 4 that generates noise at a relatively high temperature and a constant temperature T 0 is connected to the switch B7 side, and the comparison noise source 4 is transmitted through a synchronous detector in the receiver 5 that is synchronized with the switch switching operation. A voltage V is obtained that is proportional to the difference between the temperature T 0 and the antenna temperature T A . In order to achieve the observation function of a microwave radiometer, it is necessary to know the value of the antenna temperature T A based on the generated voltage V, and this value can be found by going through the following steps. be able to.
まず、スイツチＡ６の接続を側から側に切
り換える。スイツチＣ８が側の時に、スカイホ
ーン２からのアンテナ温度T1が、そして側の
時に標準雑音源３の雑音温度T2が受信機５に導
かれ、それぞれ比較雑音源４との温度差に比例す
る電圧V1およびV2が受信機５内で発生する。こ
こでスカイホーン２は常に宇宙の冷たい空間に向
けられているとすればその輝度温度は周波数の関
数として既知の量であり、同時にスカイホーン２
自身の利得関数も既知であるため、これらをもと
に受信機５の入力温度T1を知ることができる。
一方、標準雑音源３の雑音温度も標準雑音源３に
温度センサを取り付け、それをモニタすることに
よつて受信機５の入力温度T2を知ることができ
る。なおT1＜T2＜T0，V1＞Ｖ＞V2の関係があ
り、T1，T2，V1，V2およびＶがわかるとアンテ
ナ温度ＴAは次式から求まる。 First, change the connection of switch A6 from side to side. When the switch C8 is on the side, the antenna temperature T1 from the skyhorn 2 is guided to the receiver 5, and when it is on the side, the noise temperature T2 of the standard noise source 3 is guided to the receiver 5, each proportional to the temperature difference with the comparison noise source 4. Voltages V 1 and V 2 are generated within the receiver 5. Here, if Skyhorn 2 is always directed toward the cold space of space, its brightness temperature is a known quantity as a function of frequency, and at the same time Skyhorn 2
Since its own gain function is also known, the input temperature T 1 of the receiver 5 can be known based on these.
On the other hand, by attaching a temperature sensor to the standard noise source 3 and monitoring the noise temperature of the standard noise source 3, the input temperature T2 of the receiver 5 can be determined. Note that there is a relationship of T 1 <T 2 <T 0 , V 1 >V>V 2 , and if T 1 , T 2 , V 1 , V 2 and V are known, the antenna temperature T A can be found from the following equation.
ＴA＝Ｖ１Ｔ２−Ｖ２Ｔ１／Ｖ１−Ｖ２＋Ｔ１−Ｔ２
／Ｖ１−Ｖ２Ｖ……(2)
以上では説明の便宜上スイツチ等RF回路の損
失は無いものと仮定している。 T A =V 1 T 2 −V 2 T 1 /V 1 −V 2 +T 1 −T 2
/V 1 −V 2 V (2) In the above, for convenience of explanation, it is assumed that there is no loss in the RF circuit such as a switch.
以上の説明からも明らかなように、スカイホー
ン２と標準雑音源３はアンテナ温度ＴAの校正の
ために用いられる校正用雑音源である。標準雑音
源３は衛星の構体内にあり校正用雑音源として常
時使用可能であるが、スカイホーン２については
それが校正用雑音源となり得るためには、スカイ
ホーン２が常に宇宙の冷たい空間に向けられるよ
う衛星の構体に取り付ける必要がある。しかし現
実には観測地域、衛星打上げ時期等の制約から軌
道上においてスカイホーン２が常に宇宙の冷たい
空間に向けられることは極めて稀であり、一般に
はある時期にわたつて太陽、月等の影響を受ける
ことになる。その結果低雑音源としての機能が保
持されなくなり、この期間の観測は中止せざるを
得ない欠点があつた。 As is clear from the above description, the skyhorn 2 and the standard noise source 3 are calibration noise sources used to calibrate the antenna temperature T A. The standard noise source 3 is located inside the satellite body and can be used at all times as a noise source for calibration, but for the skyhorn 2 to be a noise source for calibration, the skyhorn 2 must always be in the cold space of space. It must be attached to the satellite's structure so that it can be pointed. However, in reality, it is extremely rare for Skyhorn 2 to be constantly pointed into the cold space of space while in orbit due to constraints such as the observation area and the timing of satellite launches. I will receive it. As a result, its function as a low noise source was no longer maintained, and observations during this period had to be discontinued.
そこで、この発明においては２個のスカイホー
ンを用い、スイツチで切り換えることによつて上
述の欠点を除去するようにしたものである。以下
図面によりこの発明の一実施例について説明す
る。 Therefore, in the present invention, the above-mentioned drawbacks are eliminated by using two skyhorns and switching them with a switch. An embodiment of the present invention will be described below with reference to the drawings.
第２図において、１は受信アンテナ、２ａ及び
２ｂはそれぞれスカイホーンＡ，Ｂでいずれもホ
ーンアンテナ、３は標準雑音源、４は比較雑音
源、５は受信機および６，７，８，９はそれぞれ
スイツチＡ，Ｂ，Ｃ，Ｄである。この発明におい
てはスカイホーンＡ２ａおよびＢ２ｂは衛星構体
の互いに異なる位置に取り付け、一方のスカイホ
ーンが太陽もしくは月等の影響を受ける場合は、
スイツチＤ９の切換え操作によつて他方のスカイ
ホーンが使用できるようにしたものである。この
ようにすることによつて、常にいずれか一方のス
カイホーンを宇宙の冷たい空間に向けることがで
きる。 In FIG. 2, 1 is a receiving antenna, 2a and 2b are skyhorns A and B, respectively, which are both horn antennas, 3 is a standard noise source, 4 is a comparative noise source, 5 is a receiver, and 6, 7, 8, 9 are switches A, B, C, and D, respectively. In this invention, skyhorns A2a and B2b are installed at different positions on the satellite structure, and if one skyhorn is affected by the sun or the moon,
The other skyhorn can be used by switching the switch D9. By doing this, one of the skyhorns can always be pointed toward the cold space of space.
以上では人工衛星を例にとつて説明したが、他
の飛翔体であつても差し支えない。 Although the above explanation uses an artificial satellite as an example, other flying objects may also be used.
以上述べたようにこの発明によればアンテナ温
度の校正が常時可能となり観測の中断が防止でき
る効果を有する。 As described above, according to the present invention, the antenna temperature can be calibrated at any time, and interruption of observation can be prevented.
第１図は従来のマイクロ波放射計の説明図、第
２図はこの発明の一実施例を示す図であり、図
中、１は受信アンテナ、２はスカイホーン、３は
標準雑音源、４は比較雑音源、５は受信機、およ
び６，７，８，９はそれぞれスイツチである。図
中、同一部分または相当部分には同一記号を付し
て示してある。
FIG. 1 is an explanatory diagram of a conventional microwave radiometer, and FIG. 2 is a diagram showing an embodiment of the present invention. In the figure, 1 is a receiving antenna, 2 is a skyhorn, 3 is a standard noise source, and 4 is a comparison noise source, 5 is a receiver, and 6, 7, 8, and 9 are switches, respectively. In the drawings, the same or equivalent parts are indicated by the same symbols.
Claims (1)
と、一定温度T0の雑音を発生する比較雑音源
と、温度T1の雑音を発生する温度校正用低雑音
源と、温度T2（T1＜T2）の雑音を発生する標準雑
音源と、上記受信アンテナで受信された雑音アン
テナ温度ＴAと上記比較雑音源の温度T0との差に
比例する電圧、上記温度校正用低雑音源の温度
T1と上記比較雑音源の温度T0との差に比例する
電圧、および上記標準雑音源の温度T2と上記比
較雑音源の温度T0との差に比例する電圧を得る
受信機と、上記受信アンテナの受信出力と上記温
度校正用低雑音源あるいは上記標準雑音源の出力
とを切換えるスイツチと、このスイツチと上記受
信機との間に接続され、上記スイツチからの出力
と上記比較雑音源の出力とを切換えて上記受信機
に与えるスイツチとから構成され、人工衛星等の
飛翔体に搭載して使用されるマイクロ波放射計に
おいて、上記温度校正用低雑音源として２個のホ
ーンアンテナを用い、かつ上記２個のホーンアン
テのいずれか一方を切換え選択し、その出力を、
上記２つのスイツチを介して上記受信機へ与える
ための切換スイツチを設けたことを特徴とするマ
イクロ波放射計。1. A receiving antenna that receives electromagnetic waves from an object, a comparison noise source that generates noise at a constant temperature T 0 , a low noise source for temperature calibration that generates noise at a temperature T 1 , and a temperature T 2 (T 1 < T 2 ) A standard noise source that generates the noise, a voltage proportional to the difference between the noise antenna temperature T A received by the receiving antenna and the temperature T 0 of the comparison noise source, and the temperature of the low noise source for temperature calibration.
a receiver that obtains a voltage proportional to the difference between T 1 and the temperature T 0 of the comparison noise source, and a voltage proportional to the difference between the temperature T 2 of the standard noise source and the temperature T 0 of the comparison noise source; A switch is connected between the receiving output of the receiving antenna and the output of the low noise source for temperature calibration or the standard noise source, and the switch is connected between the switch and the receiver, and the switch is connected between the output of the receiving antenna and the output of the low noise source for temperature calibration or the standard noise source. In a microwave radiometer used on board a flying object such as an artificial satellite, two horn antennas are used as low noise sources for temperature calibration. and select one of the above two horn antennas, and output the
A microwave radiometer characterized in that it is provided with a changeover switch for supplying power to the receiver via the two switches.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP982879A JPS55101826A (en) | 1979-01-31 | 1979-01-31 | Microwave radiometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP982879A JPS55101826A (en) | 1979-01-31 | 1979-01-31 | Microwave radiometer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55101826A JPS55101826A (en) | 1980-08-04 |
| JPS6237345B2 true JPS6237345B2 (en) | 1987-08-12 |
Family
ID=11730985
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP982879A Granted JPS55101826A (en) | 1979-01-31 | 1979-01-31 | Microwave radiometer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55101826A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150185088A1 (en) * | 2013-12-31 | 2015-07-02 | i4c Innovations Inc. | Microwave Radiometry Using Two Antennas |
-
1979
- 1979-01-31 JP JP982879A patent/JPS55101826A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55101826A (en) | 1980-08-04 |
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