JP2012251918A - Device for generating radioactivity amount distribution information - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for generating radioactivity amount distribution information on the surface of the earth in a wide range with improved location accuracy.SOLUTION: A device measures a measurement area which is divided into a plurality of sub-areas at each of a plurality of measurement positions in the sky above the surface of the earth, or in a plurality of directions along measurement positions which continuously change in the sky above the surface of the earth by a radioactivity amount measurement device, acquires a plurality of pieces of measurement information, stores measurement position information, measurement direction information, and measurement time in a memory, specifies a sub-area measured when the measurement information is acquired, and refers to the measurement information which is associated with the sub-area to generate radioactivity amount distribution information on the surface of the earth by an operation.

Description

  The present invention relates to an apparatus for measuring a radioactivity distribution on the ground surface. In particular, the present invention relates to a system that uses γ-ray dosimetry values measured from above in an aircraft or the like and a device that generates a radioactivity distribution map, and also relates to a device that presents or displays a radiation dose to any point on the ground. .

Conventionally, as a technique for measuring the radiation dose, there is a monitoring post for fixed point observation by a γ-ray scintillator, or a method of measuring the radiation dose on the ground or in the air by suspending the γ-ray scintillator from a helicopter. Furthermore, in the medical field, there is a technique for obtaining a dose distribution with respect to γ rays for the human body. However, the method of obtaining the radiation distribution over the surface area without entering the site is a method to measure the radiation dose on the ground or in the air by hanging a gamma ray scintillator from a helicopter as a monitoring post for fixed point observation or as a modification of it There is no other than. . It is necessary to measure the radioactivity distribution over a wide area of the earth, as far as it is publicly available, only the nuclear test site and the Chernobyl and Fukushima nuclear power plants contaminated by the accident. This is probably because there is no need for high-precision and high-resolution measurement. In the following, the term radioactivity is expressed in terms of becquerel, and what is measured in the present invention is the γ-ray count number and gamma ray spectrum that can be converted to becquerel, and the radioactivity on the ground surface is becquerel / m2. Since a γ-ray spectrum can also be measured, it can be converted into a radiation dose.

Of radioactivity, measurement of gamma rays with strong penetrating power is important for radiation protection, but due to the nature of gamma rays, it is impossible to image the distribution by configuring an optical system like visible light. Therefore, it has not been easy to obtain directivity. For this reason, a mobile gamma ray scintillator is placed close to the radiation source, or a plurality of gamma ray scintillators are arranged as a collimator by a shield in two or three dimensions, and the position of the radiation source is obtained from the relative positional relationship with each scintillator. There are methods for obtaining a distribution and an image.

  In the method of Patent Document 1, in order to image a source distribution spreading in three dimensions, or to specify a source position and a radiation flight direction, γ-ray sensors are three-dimensionally arranged in a grid pattern, The position of the radiation source is determined by numerical calculation based on the relative positional relationship with the radiation source. In the method of Patent Document 2, various radioactive contamination sensors are mounted on a traveling inspection carriage that measures the contamination due to radioactivity on the surface of the structure to be inspected and the material in the structure to be inspected, and close to the radioactive contamination portion by itself. By doing so, the radioactivity distribution is measured.

  In the method of Patent Document 3, a lifting mast with a variable mounting mount is attached to a lifter carriage, a scintillation detector is attached, and a ceiling that has conventionally been difficult to survey in a radioactive contamination area of a management area such as a nuclear power plant and This is a device for inspecting radioactive contamination at high places that can be easily handled even on high walls. The method of Patent Document 4 is a method of obtaining an image with a plurality of γ-ray cameras for medical use on a human body placed on an examination table.

The method of Patent Document 5 is a method of improving the sensitivity by reconstructing the information of the γ-ray sensor together for the human body placed on the examination table. The method of Patent Document 6 is a technique for storing a wide-area photograph in association with a position and a shooting direction by using a plurality of cameras using an aircraft, and generating an image from an arbitrary viewpoint. It is a photographic image.

  The methods of Patent Literature 2 and Patent Literature 3 are for obtaining a dose distribution by measuring a gamma ray sensor close to an object and changing the position. It cannot be used for measurements from. The method of Patent Document 1 is characterized in that gamma ray sensors are arranged in a grid pattern and the direction information of the radiation source is calculated, but it is assumed that both the measurement system and the object are fixed, and the existence of the measurement object. It is assumed that the position is close to the measurement system and the measurement object is on the entire surface of the opening of the measurement system.

  Patent Document 4 and Patent Document 5 are for medical use, and are techniques for fixing a human body on an examination table and obtaining an image of γ rays from the vicinity. It is not suitable for applications that measure gamma dose distribution over a wide range from a distance. Patent Document 6 is a method for comprehensively capturing images of a wide area and an entire circumference from an aircraft for all points, and the aircraft control and imaging control method is a technique suitable for wide area measurement from an aircraft. Assuming photography, it cannot be used to measure the gamma dose distribution on the surface except air traffic control methods and precision geodetic techniques.

JP 2011-85418 JP 2007-333419 JP 2005-274367 A WO-2009 / 051053 WO-2008 / 139625 WO-2008 / 139625

  The problem to be solved by the present invention is, first of all, that the radioactivity distribution of a wide area of the ground surface contaminated by radioactivity is subjected to mote sensing with an aircraft from above without entering the ground. It is to make it below the limit value and further reduce as much as possible. The second is to present the measured value as a radioactivity distribution on the map as soon as possible after measurement, and to increase the positional accuracy and resolution of the radioactivity distribution as much as possible. That is, γ-ray dose distribution from the ground surface is measured with high positional accuracy and high spatial resolution while scanning the ground surface at a high speed from a long distance by remote sensing.

Using a sodium iodide (NaI) scintillator that is widely used as a gamma-ray sensor to create a sharp beam with directivity from a long distance reduces the number of incident photons, lowering the sensitivity, and making the measurement longer Time is needed. In addition, if a γ-ray scintillator is mounted on an aircraft and flies at high speed, the number of photons incident on individual ground areas decreases (decrease in sensitivity), requiring measurement for a long time while moving, resulting in poor resolution. . Furthermore, when the number of incident photons decreases, the noise for the measurement value increases due to the background radiation dose derived from cosmic rays and the like. Furthermore, if the measurement time for each individual ground region is short, the γ-ray itself is a stochastic phenomenon derived from the decay of the nucleus, and thus the stochastic fluctuation cannot be ignored. It is an object of the present invention to solve the above problems in the situation where there is no effective refraction or reflection means for γ rays and a lens or reflecting mirror such as visible light cannot be constructed.

In order to obtain surface distribution information of γ-ray dose from a remote location, it is necessary to give directivity to the sensitivity of the γ-ray scintillator. The directivity is obtained by shielding gamma rays from directions other than the incident angle required by the lead shield. When the sensitivity directivity of the γ-ray scintillator is increased, the ground area that can be measured simultaneously from a remote area becomes narrower, and in order to measure the ground wide area, the flight path must be set densely. In order to reduce the radiation exposure of the pilot, it is not preferable, and in order to solve this problem, a plurality of γ-ray scintillators directed in different directions are assembled to form a γ-ray scintillator assembly, and at the same time multi-directional To be able to measure the dose of γ rays. As for the method of surrounding the γ-ray scintillator with a shield, increasing the directivity reduces the number of incident photons and decreases the sensitivity, so environmental radiation from directions other than the directivity selected for the purpose of improving the S / N ratio. To shield. The arrangement of each γ-ray scintillator partially overlaps each other spatially, and the S / N ratio is improved by performing γ-ray measurement so that there is an integration effect in terms of time. ,

In order to make the arrangement of each γ-ray scintillator partially overlap each other spatially and have an integration effect in time, the position of the ground surface measured by each γ-ray scintillator is accurate, The time integration effect needs to be appropriate. For this reason, in order to increase the measurement accuracy, the flight path is set at, for example, the same altitude from the ground surface, at equal intervals, or, for areas that need to be measured precisely, for example, the flight path is lower at the lower altitude and narrower from the ground surface. It is indispensable to fly exactly on the planned flight path.

For this purpose, the flight route is planned in advance on a map, output as flight control measurement control data to the flight control γ-ray data measurement system mounted on the aircraft, and the position is measured in real time by DGPS with high accuracy. A flight control system that can instruct the pilot to fly in real time so as not to deviate from the above. Furthermore, measurement data is acquired continuously from a plurality of γ-ray scintillators at accurate positions, and automatically recorded together with latitude / longitude data acquired from DGPS and measurement time.

Light aircraft are disturbed in attitude, and pitch and yaw (tilt back and forth, left and right) fluctuate up to 5 degrees during measurement. Also, the nose direction may deviate about 20 degrees from the direction of travel. This disturbance causes an error in associating the measured value of each γ-ray scintillator with which part of the ground surface. To correct this, data directly below the aircraft body is automatically acquired. Then, the posture of the γ-ray scintillator assembly at the time of measurement is calculated, and after the measurement, the directivity direction of a plurality of γ-ray scintillator measurement values and the center position on the map are automatically calibrated to ensure the positional accuracy of the radiation dose. Instead of calculating the posture of the γ-ray scintillator assembly at the time of measurement, the γ-ray scintillator assembly may be fixed on a stable platform installed on the airframe to maintain a constant posture.

Since each γ-ray scintillator measurement data measured and recorded on the plane by the above measures is accurately associated with the position on the map, the γ-ray scintillator measurement value of the small area of 5 to 50 m on the map Integrate temporally and spatially to improve the sensitivity of γ-ray scintillator measurements and improve the S / N ratio. Using the γ-ray scintillator measurement value calibrated in this way, it is displayed on the map as radioactivity distribution data. In this way, by making the radioactivity distribution correspond to the map, the radioactivity can be displayed for the designated latitude and longitude.

  As described above, according to the present invention, the gamma ray dose distribution can be measured at high speed without entering the ground in a wide area by an aircraft, so that the radioactively contaminated area and the degree of contamination can be displayed on a map. Can be presented as a distribution. This can also indicate an uncontaminated area. Since the radioactivity distribution measuring method according to the present invention can remotely and rapidly measure the γ-ray dose distribution, it also has a safety effect of reducing the exposure dose of pilots and the like that are subjected to the measurement.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following description, and various modifications can be made without departing from the scope of the invention.
The inventor of the present application is difficult to measure the ground surface over a long time in order to reduce the radiation exposure of the measurer in the realization of the radiation amount distribution information generating device for the ground surface contaminated by the nuclear power plant accident etc. Therefore, it was recognized that it was necessary to quickly obtain information on the distribution of radioactivity on the surface of the earth in order to prevent radiation disasters. On the other hand, when measuring the surface radioactivity distribution, γ-ray scintillators are widely used, but when measuring remotely, it is necessary to narrow the directivity to identify the position of the radiation source, If the directivity is reduced, the number of photons incident on the aperture is reduced, and the sensitivity is lowered. In general, in such a case, a method of increasing the number of incident photons by fixing the γ-ray scintillator for a certain period of time is used. However, when the γ-ray scintillator is mounted on an aircraft for remote measurement, the γ-ray scintillator is fixed. It is not possible to adopt this method. As a result, in γ-ray measurement that lacks a condensing means such as lens, sufficient sensitivity cannot be obtained when measuring gamma dose distribution by remote measurement by aircraft, and sufficient resolution is obtained due to sensitivity limitations. I came to realize that they lacked the means.

  For this reason, the present inventor increases the directivity of the γ-ray scintillator, and simultaneously measures a spatial integration effect, that is, synchronously measures a plurality of γ-ray scintillators that radially measure different ground areas while partially overlapping each other. At the same time, a method is adopted in which the surface area to be measured is overlapped on the same γ-ray scintillator and measured continuously in a certain time period in the direction of travel. The idea was to improve the measurement sensitivity and improve the S / N ratio by integrating after measurement.

In order to increase the directivity of the γ-ray scintillator, the lead shield is shaped into a horn shape (trumpet shape), placed in the front opening of the sodium iodide (NaI) crystal, and the sides and back are shielded with lead. To prevent the measurement of environmental radiation from cosmic rays from the side and back. Further, in order to accurately integrate the γ-ray scintillator measurement values, the positions and measurement directions at the time of measurement of a plurality of γ-ray scintillators must be accurately obtained as planned.

For this reason, in setting the flight route of the aircraft, the altitude and the route interval are set on the map so that the integration effect of the γ-ray scintillator measurement value can be sufficiently obtained. The γ-ray scintillator assembly has a directivity that extends perpendicularly to the direction of travel with respect to the plane immediately below the aircraft and spreads radially and fan-shaped around the vertical direction. In this case, set the route and flight altitude so that the measurement area (footprint) on the surface overlaps with the adjacent route so that there will be no measurement omission on the surface, and the γ-ray measurement value Make integration effect.

The γ-ray scintillator needs to integrate incident photons for 0.5 to 1 second at the shortest, and must be measured while moving on an aircraft. The measurement range (referred to as footprint) on the ground surface of the γ-ray scintillator is repeatedly measured while shifting by 0.5 to 1 second in the flight direction of the aircraft. The measured value is read from the γ-ray scintillator every 0.5 to 1 second and stored in the storage device together with the position, orientation, and time.

All gamma scintillator measurements must be accurately integrated on the map, so the flight control system can accurately determine the aircraft position with DGPS and give the pilot to fly along a pre-planned route. Maneuver instructions. The γ-ray data automatic measurement system automatically stores the γ-ray data measurement value together with the position, the γ-ray scintillator assembly direction, and the time when it is closest to a predetermined point on the route.

Measurement position after flying along a predetermined route and acquiring and storing all the measured values of γ-ray data together with associated data at predetermined points. Accurately specify the measurement direction, calculate from the γ-ray scintillator aperture characteristics which part of the ground surface the γ-ray data measurement value corresponds to, and integrate all γ-ray data measurement values according to the ground surface position Devised a method to post the gamma dose distribution on the surface.

    FIG. 1 is a diagram schematically showing an overall configuration of a radioactivity amount distribution information generating apparatus according to the present embodiment. The measurement route setting system 100 is a system for setting a route for measurement when an area in which the radioactivity distribution is to be measured is determined from above, and measuring points by a γ-ray scintillator on the flight route are set to latitude, longitude, It is defined by altitude, a flight path is defined as a chain of measurement points, and is generated and output as a radiation data acquisition plan file 101. The measurement route setting system 100 does not need to be mounted on an aircraft, but may set a route using a GIS (geographic information system) publicly implemented on the ground and output the result. FIG. 2 shows an example in which a route is set on a map, and it is desirable for the route to be straight lines parallel to each other in order to stabilize the flight attitude and to accurately integrate the measurement data. When the measurement route setting system 100 is realized as a ground system, the radiation data acquisition plan file 101 is recorded in, for example, a USB memory in the flight control / γ-ray data automatic measurement system 102 that controls flight and data acquisition on the aircraft. Enter.

The flight control / γ-ray data automatic measurement system 102 performs flight control of the aircraft on the aircraft based on the radiation data acquisition plan file 101, performs measurement with a γ-ray scintillator at a predetermined measurement point on a predetermined route, and performs primary measurement information. As file 103, γ-ray data measurement value 104, DGPS measurement value 105, measurement time 106, and sensor attitude measurement information 107 are stored.

The γ-ray data calibration / distribution calculation system 110 is a system for calculating in detail the radioactivity distribution 113 on the ground surface based on the contents of the measurement information primary file 103 on the ground after all measurements of the flight control / γ-ray data automatic measurement system 102. It is. γ-ray scintillator opening characteristic data 260 describes the directivity of the measuring instrument, Geoid file 112 corrects DGPS measurement value 105, DEM file 111 corresponds to ground surface undulation, and corresponds to γ-ray scintillator opening characteristic data 260 Accurately determine the footprint of the γ-ray scintillator on the ground surface. The footprint data corrected in this way is integrated to calculate the radiation amount distribution 113, and the radiation amount is displayed on the map by the graphic user interface system 115 by, for example, color-coding by the publicly implemented GIS software. The radioactivity distribution 113 can be used for browsing of the user 117 via the publicly implemented Internet 116.

FIG. 3 is a diagram showing the concept of data acquisition of the flight control / γ-ray data automatic measurement system in the radioactivity distribution information generating apparatus shown in FIG. 1. The aircraft 120 is measured along the flight path 121. At point 122, measurement is performed with a γ-ray scintillator. Since it is necessary to perform integral measurement of photons incident for a certain period of time based on the characteristics of the γ-ray scintillator, at the measurement point 122, the integration data from the previous measurement point is read and the accumulated value of the γ-ray scintillator is cleared. The plurality of γ-ray scintillators mounted on the aircraft 120 has directivity in the central axis direction 123 of the γ-ray scintillator. The total measurement range on the ground of each γ-ray scintillator is as shown in the footprint 124 of the γ-ray scintillator, and the aircraft 120 advances in the traveling direction 125 with time.

FIG. 4 shows an example in which a helicopter is used as an aircraft. By suspending the γ-ray sensor assembly 130 on the suspension cable 132, measurement closer to the ground surface can be performed at a lower speed than a light aircraft. In the case of a light aircraft, it is possible to stabilize the pointing direction of the gamma-ray sensor assembly 130 by fixing it to the floor of the aircraft or using a publicly implemented attitude stabilization device, but it is suspended by a helicopter In this case, it is necessary to suspend the γ-ray sensor assembly 130 fixed to the stabilization device 131.
FIG. 5 describes the contents of (0021) to (0026) in a functional flow diagram.

FIG. 6 shows the structure and shielding structure of the γ-ray scintillator used in the flight control / γ-ray data automatic measurement system 102 of the radioactive quantity distribution information generating apparatus according to the present invention. FIG. 6B is an axial sectional view of the γ-ray scintillator and has a rotationally symmetric shape with respect to the γ-ray scintillator central axis 161. NaI 156 is a cylindrical sodium iodide crystal viewed from the side perpendicular to the axis. The most commonly used is 3 inches long and 3 inches in diameter. Uses larger crystals. The photoelectron detection and counting unit 157 is a device that amplifies and counts the light emitted from the γ-ray photons incident on the NaI 156 from above in FIG. 6 (b) with a photomultiplier tube. The photon detection and counting unit 157 calculates the number of incident photons on the NaI 156 and the γ-ray energy spectrum. The counting gamma scintillator is publicly implemented and sold as a product.

In FIG. 6B, the material of the directivity shield 159, the side shield 158, and the back shield 160 is lead, and is installed so as to surround the γ-ray scintillator 155 for the purpose of shielding γ-rays. In order to have a sufficient shielding effect against γ rays, the thickness is desirably 5 cm or more. The directivity shield 159 has a trumpet shape, forms a conical opening made of OA and OB, and has γ-ray sensitivity directivity around the γ-ray scintillator central axis 161. FIG. 6A is a diagram showing the axial sensitivity directivity of the γ-ray scintillator, and corresponds to the cross-sectional view of FIG. Due to the presence of the directivity shield 159, the sensitivity directivity indicated by the directivity characteristic 162 can be provided in the acute angle direction surrounded by OA and OB. The reason why the directivity characteristic 162 in the obtuse angle direction surrounded by OA and OB is not 0 is that the directivity shield 159 has a finite length and the directivity cannot be limited to the acute angle direction surrounded by OA and OB.

FIG. 7 is a configuration diagram of a γ-ray scintillator assembly 130 configured by arranging a plurality of γ-ray scintillators 155 of FIG. 6 in a fan shape. FIG. 7A is a layout diagram of γ-ray scintillators viewed from above vertically, and FIG. 7B is a diagram when the AB axis of FIG. 7A is viewed from the horizontal direction. FIG. 7 shows the arrangement of the γ-ray scintillator in order to realize the central axis direction 123 of the γ-ray scintillator and the footprint 124 of the γ-ray scintillator shown in FIG. The γ-ray scintillator 155 and surrounding shield shown in FIG. 6 are represented by a γ-ray scintillator 1 170, a γ-ray scintillator 2 171, a γ-ray scintillator 3 172, a γ-ray scintillator 4 173, and a γ-ray scintillator 5 174, respectively. The γ-ray scintillator 3 is arranged symmetrically with the central axis 177 as the central axis OC of the fan.

The γ-ray scintillators 1 to 5 170 to 174 have γ-ray scintillators 1 each having an angle formed with the γ-ray scintillator 3 and the central axis 177 on the left and right of the respective central axes γ-ray scintillators 1 to 5 and 175 to 179. , 2 deviation angles 180, 181 and γ-ray scintillators 4, 5 deviation angles 182, 183. The purpose of the radial arrangement is to realize the footprint 124 of the γ-ray scintillator of FIGS. 3 and 9 on the ground surface, and therefore the γ-ray scintillators 1 to 5 170 to 174 are straight lines in FIG. Arranging in a line on AB is not an essential requirement. If space is not allowed, the AB axis is disassembled into two lines, AB and AABB, as shown in FIGS. 20 (b) to (c). The γ-ray scintillator 3172 having directivity may be modified so as to be arranged at the center. Also, γ-ray scintillators 1-5
It is not necessary for the central axis 175 to 179 to converge to one point of the declination center O184. Further, the number of γ-ray scintillators is not limited to 5, but can be increased or decreased within the range allowed by weight and space. The purpose is to set the shape of the footprint 124 of the γ-ray scintillator so as to be suitable for the integration calculation on the ground surface of the γ-ray measurement value described later, which is performed in order to calculate the surface radioactivity distribution.

The shape of the footprint 124 of the γ-ray scintillator is set so as to be suitable for the integration calculation on the ground surface of the γ-ray measurement value described later for displaying the ground surface radiation distribution. FIG. 21B, FIG. 21C, and FIG. 21D show modified examples of the shield for the γ-ray scintillator in FIG. The γ-ray scintillator shield structure in FIG. 5 corresponds to (e) in FIG. In other words, the directivity shield 159 is rotationally symmetric in the axial direction of the cylindrical NaI156, but the footprint formed on the ground surface by the directivity of such a shape (the area where the sensitivity is high and γ-ray data can be measured) is Except for the direction directly below the aircraft 120, it is not a circle, but has an elliptical distorted shape that expands as the distance from the direct point increases. In order to make the footprint of each γ-ray scintillator along the measurement direction 152 of FIG. 4 and FIG. 9 suitable for integration calculation on the ground surface of the γ-ray measurement value described below, which is performed to calculate the ground surface radioactivity distribution, An example in which the directivity shield 159 is modified is shown in FIGS.

21 (b), (c), (d), and (e) are views of the γ-ray scintillator and the shield shown in FIG. 21 (a) γ-ray scintillator axial sectional view as viewed from above, which is an opening. A lateral cross-sectional view along the straight line AbBb in FIG. 21 (b), a straight line AcBc in FIG. 21 (c), and a straight line AdB in FIG. 21 (a) is a sectional view in the axial direction of the γ-ray scintillator. . Except for FIG. 21 (e), it is not rotationally symmetric in the axial direction of NaI156. FIG. 21D shows the directivity in the measurement direction 152 compressed so that a footprint having an off-nadir angle in the measurement direction 152 from the vertical point of the aircraft 120 becomes a circle on the ground surface. The directivity becomes narrower as the off-nadir angle increases on a straight CD, but the shape of the footprint can keep a circle even when the off-nadir angle increases.

FIG. 21 (c) is a view of the γ-ray scintillator with the directivity shield 159 for making the footprint at the point immediately below the aircraft 120 square, as viewed from above. Even when the footprint is rectangular, the footprint increases as the off-nadir angle increases. Also in this case, when the γ-ray scintillator with the directivity shield 159 is viewed from above as shown in FIG. 21B, the footprint shape remains rectangular even when the off-nadir angle increases. Can do.

Although the γ-ray scintillators are arranged in a fan shape in FIG. 7, it is not necessary to place each γ-ray scintillator at an equal distance from the declination center O 184. FIG. 8 shows a configuration in which the lower surfaces of the γ-ray scintillators 1 to 5 170 to 174 are aligned with a plane CD. Since the lead of the shield is heavy, the support structure can be reduced in weight by aligning the lower surface on a flat surface. Since γ rays have a strong penetrating power and easily pass through the lower surface of the aircraft, the flat CD may be the aircraft floor surface, and in particular, no shooting hole is required on the floor surface.

  FIG. 9 shows a setting example of the route and measurement point of the flight control / γ-ray data automatic measurement system 102 by the aircraft 120. FIG. 9B shows an example of setting the measurement point 122. The flight path 121 travels in a reciprocating manner by making a U-turn as shown by a dotted line in FIG. 9 (b) so as to form a mesh of measurement points 122 in the air in parallel at equal intervals. During this time, gamma ray measurement data is acquired at the measurement point 122. The mutual distance between the measurement points 122 is determined by the sensitivity of the γ-ray scintillator and the required spatial resolution of the radioactivity distribution on the ground surface. That is, since it is desirable for the γ-ray scintillator to integrate and measure incident photons for about 0.5 seconds to 1 second, the measurement point 122 for acquiring gamma ray measurement data is set at intervals of about 20 m to 100 m when the speed is about 50 m / sec. For the altitude of the channel, if the footprint size is set to a radius of 100 m, the integration of the outermost edges of the γ-ray scintillator footprint 124 in FIG. Therefore, the navigation interval is 200 m to 500 m.

FIG. 9A shows each measurement point in FIG. 9B.
The footprint in 122 is enlarged and displayed. The footprint 124 of the γ-ray scintillator is the measurement range (footprint) 185 of the γ-ray scintillator 1, the measurement range (footprint) 186 of the γ-ray scintillator 2, and the measurement range (footprint) of the γ-ray scintillator 3 for each γ-ray scintillator. 187, the measurement range (footprint) 188 of the γ-ray scintillator 4 and the measurement range (footprint) 189 of the γ-ray scintillator 5 are superimposed. The measurement point 122 is a position where the measurement data is captured and stored from each γ-ray scintillator, and each γ-ray scintillator measures the incident gamma rays after the previous measurement point 122, so the measured value of each γ-ray scintillator is the integration interval.
The sum is 127. In order to improve the sensitivity by integrating the measured values and at the same time improve the spatial resolution by calculation, it is preferable to overlap the footprints of each γ-ray scintillator as shown in FIG. Since the measurement value obtained at the measurement point 122 is an integral value in the integration section 127, the footprint of each γ-ray scintillator is increased by the length of the integration section 127 in the traveling direction of the flight path 121.

FIG. 10 is a diagram showing a configuration example of the flight control / γ-ray data automatic measurement system 102. The flight control / γ-ray data automatic measurement system 102 includes a flight navigation system unit 225 and a data acquisition / recording system unit 226. The flight navigation system unit 225 is a device for guiding the aircraft 120 to the measurement point 122 defined in FIG. 9B along the flight path 121, and aircraft position data is periodically obtained from the DGPS 210. As for the attitude of the aircraft, data including pitch, yaw, roll, and time is obtained as attitude calibration data by the attitude acquisition command by the attitude sensor 223. (Attitude acquisition command and attitude calibration data
224) Attitude sensor 223 is most commonly an inertial sensor such as a gyroscope, but since the aircraft 120 flies in a nearly constant attitude on a straight channel, the image below the fuselage from the aerial camera floor hole 219 is used as data. At the time of acquisition, it is possible to obtain posture calibration data by photogrammetry in combination with DGPS position data compared to a map. Information on the attitude of each γ-ray scintillator can be calculated from the attitude of the aircraft and the relative position and orientation of the γ-ray scintillator with respect to the aircraft.

The function of the flight navigation system unit 225 is the radiation data acquisition plan file 101 of FIG.
The pilot is guided by the pilot LED route indicator 200 of FIG. 12B by the processing flow of FIG. 13 of the flight navigation system portion of the flight control / γ-ray data automatic measurement system 102 of FIG. . Although the flight navigation system itself has already been publicly implemented and may not be anything novel, the part that efficiently and accurately guides the aircraft to the measurement point 122 in order to realize the object of the present invention is related to the present invention. Part. First, determine the area from which radiation dose data will be acquired before flight. Determine the data acquisition range on the map and formulate a flight plan. The flight plan is performed by setting the flight route 121 on the aerial map. FIG. 2 shows an example.

  The measurement point 122 may be set in a high-density network having a height in the range of 50 m to 2500 m, preferably 300 m to 500 m, so as to achieve the object of the present invention. Based on the setting result, the flight path 121 is set to be constituted by parallel lines. The route number shown in the radiation data acquisition plan file 101 of FIG. 11 is assigned to each straight line portion, and measurement point coordinates 1 to n are assigned so as to form a mesh as a whole for each route, and the start coordinates and end coordinates of each route. In addition, the number of measurement points and the coordinates of each measurement point are set in latitude and longitude and altitude. In this way, the radiation dose data acquisition plan file 101 of FIG. 11 is constructed. The graphic user interface related to the construction of the radiation dose data acquisition plan file 101 can be implemented as a map information system.

  The function of the flight navigation system unit 225 is shown by the processing flow of the flight navigation system unit 225 of the flight control / γ-ray data automatic measurement system 102 shown in FIG. In the processing block 220, the display shown in FIG. 12B is sequentially performed until all the measurements are completed for the route number scheduled for flight from the route numbers registered in the radiation dose data acquisition plan file 101. Since the designated route number has a start coordinate, in order to start the route number in the processing block 221, for example, the direction, distance, altitude difference from the current position of the route start point, and the route traveling direction are shown in FIG. (B) Numerical display windows 1 to 4 Displayed in 202 to 205, give guidance to the entrance to the route, and start the route. In order to perform automatic measurement, it is preferable to satisfy the conditions defined in the processing block 221 with a certain error range, for example, a positional error of 10 m to 30 m or less and a flight direction error of 5 ° or less. If not satisfied, the flight route may be restarted. In the case of redoing, the guidance of the processing block 221 is performed again in the processing block 223.

When the condition of the processing block 222 is satisfied, γ-ray measurement data acquisition of the latest measurement point of the route number selected in the processing block 223 is performed. In processing block 224, accompanying data (position, time, posture) of the γ-ray measurement is acquired and stored. Further, in processing block 225, the measurement data and accompanying data are transferred to the measurement information primary file 103 shown in FIG. The processing from the processing blocks 221 to 225 is sequentially repeated until the end measurement point of the route number or the departure from the route.

FIG. 12A illustrates the relationship between the processing of the processing blocks 221 to 225 and the movement of the aircraft. A measurement point 122 is indicated by numerical values 1 to 4 with respect to the flight route 121. If there is an aircraft at the point indicated by aircraft position 150, the allowable measurement range of the measurement point indicated by a numerical value of 1
Close to 193. The aircraft course deviation indicator 201 in FIG. 12B is an indicator in which LEDs are arranged. The LED center indicator 206, the LED left deviation display portion 207, and the LED right deviation display portion.
Composed of 208.

When the aircraft position 150 is in the vicinity of the flight route 121 (for example, within 5 m), the LED center indicator 206 is lit. When the aircraft position 150 is off to the right of the flight route 121, the LED right deviation display portion 208 increases the deviation. Therefore, the LED on the right side lights up. LED lighting is 5-10m, 10-20m, 20-30m, 30-40m, 50-70m, 70-100m, 100-150m, 150-200m, 200m, etc. Good. When the aircraft position 150 deviates to the left with respect to the route, the LED left deviation display portion 207 is turned on in the same manner. The pilot can pass the measurement allowable range 193 at each measurement point 122 in FIG. 12A by correcting the deviation from the route while looking at the aircraft course deviation indicator 201. Since the aircraft position 150 is measured in real time by the DGPS 210, the measured value is read from each γ-ray scintillator at the time of re-approaching each measurement point, and at the same time, the measurement value integration is reset. Hereinafter, it repeats until all the measurement points are completed.

  Next, the data acquisition / recording system unit 226 will be described with reference to FIG. In FIG. 10, the aircraft 120 has an aircraft floor hole 219 for installing an aerial photographer below the fuselage. When installing the γ-ray scintillator assembly 130, it is preferable to install the γ-ray scintillator assembly 130 so as not to protrude from the hole. Note that γ-ray scintillators may be installed on the floor regardless of this hole because γ-rays themselves have high penetrating power, but when using a direct shooting camera as the attitude sensor 223, the camera part should be Install so that it does not come out of the machine from the hole. The γ-ray scintillator assembly 130 shown in FIG. 10 can be installed on a stable platform to maintain a constant posture. In this case, regardless of the attitude of the aircraft 120, the γ-ray scintillator assembly 130 is always directed directly below the ground, and the direction is fixed in a specified direction. It should be noted that the stable platform device 395 may be omitted if the pitch and roll of the aircraft can always be controlled within 5 °.

The data acquisition and recording system unit 226 includes an attitude sensor 223 for observing the attitude of the aircraft 120, a γ-ray data automatic measurement control system 212 including a program for controlling the γ-ray scintillator and processing measurement data, and γ-ray measurement data 214. Measurement information primary file 103 composed of a memory device such as a large-capacity disk device for storing various data including γ-ray scintillator aggregate 130. The control command 218 for the gamma ray scintillator assembly 130 is the DGPS that the flight control PC 212 of the flight navigation system unit 225
The position measurement value by 210 is compared with the measurement point position in the radiation data acquisition plan file 101, and a command is issued when it is determined that the position is a measurement point. The data acquired as a result is acquired as acquired measurement data 217 by the automatic γ-ray data measurement control system 212 and stored in the measurement information primary file 103 together with accompanying data.
The antenna of the DGPS 210 for measuring the position of the aircraft 120 is installed in a place where the field of view can be opened upward.

FIG. 14 shows the structure of the measurement information primary file 103 shown in the processing block 225 of FIG. The data structure of the measurement information primary file 103 is structured for each measurement point as data 227 by measurement point. The measurement point-specific data 227, which is a set of measurement points, is further grouped by route No. as a higher structure. As shown in FIG. 14, measurement data and the like are stored for each measurement point. Aircraft data portion 222 includes the measurement position (position (latitude / longitude / altitude) 262) recorded for each measurement point, the attitude of the aircraft or attitude data 263 of the gamma sensor assembly 130, and the time when the position measurement was performed by DGPS. Recorded as UTC date 261 in UTC. The measurement data ID 231 is usually an identification number including a route number and a measurement point number in the route.

The γ-ray scintillator-specific data 228 is obtained by recording the measured values of each γ-ray scintillator at the measurement position shown in the aircraft data portion 222 for each γ-ray scintillator. The measurement data header portion 220 indicates data for each γ-ray scintillator, the γ-ray scintillator ID 230 is an identification number of the γ-ray scintillator, and the number of spectra 232 defines the number of γ-ray spectra obtained by the measurement of the γ-ray scintillator. . The measurement start date / time 233 is the time when the individual γ-ray scintillator started measurement, the measurement end date / time 234 is the time when the individual γ-ray scintillator started measurement, and the measurement date / time 261 depends on the computer processing time. May differ by ms. The γ-ray data portion 221 is composed of a count value obtained by dividing the energy spectrum of γ-rays and counting each spectrum band, and a total count number 246 obtained by summing the count values of all spectrum bands.

The flight control / γ-ray data automatic measurement system 102 shown in FIG. 1 has been described above. Hereinafter, the γ-ray data calibration / distribution calculation system 110 will be described. The function of the γ-ray data calibration / distribution calculation system 110 calculates a radioactivity distribution 113 from the measurement information primary file 103 obtained by the flight control / γ-ray data automatic measurement system 102. FIG. 15 shows the processing contents. In the processing blocks 252 and 253, all the measurement point data 227 and γ-ray scintillator data 228 shown in FIG.
Measurement time 235
Measurement start point position (latitude, longitude, altitude) 236
Measurement start point posture (pitch, yaw, roll) 237
Measurement start point normalized center axis vector t (XYZ) 238
Measurement start point frame rotation angle 239
Measurement start center axis ground distance 240
Measurement end point position (latitude, longitude, altitude) 241
Measurement end point posture (pitch, yaw, roll) 242
Measurement end point normalized center axis vector t (XYZ) 243
Measurement end point frame rotation angle 244
Measurement end point center axis surface distance 245
To calculate. The calculation method will be described with reference to FIG.

At the same time as reading measurement data from each γ-ray scintillator, the measurement count is reset and measurement data is restarted, so the count measurement time 235 is the difference between the previous measurement data read time and the current measurement data read time. It becomes. Aircraft data part 222 position (latitude, longitude, altitude) Measurement start point position (latitude, longitude, altitude) 236 by interpolating measurement start date time 233 and measurement end date time 234 from 262 time series The end point position (latitude, longitude, altitude) 241 can be calculated. Similarly, the aircraft attitude of the measurement start date / time 233 and the measurement end date / time 234 is obtained from the time series of the attitude data 263 of the aircraft data part 222, and from the γ-ray scintillators 1 to 5 declination 180 to 183 of each γ-ray scintillator. The ground orientation of each γ-ray scintillator can be calculated. Measurement start point normalized center axis vector t (XYZ) 238 Measurement start point frame rotation angle 239 Measurement end point normalized center axis vector t (XYZ) 243 Measurement end point frame rotation Angle 244 can be determined. These calculations can be done by textbook methods using quaternions.

By correcting the measurement start point position 236 and the measurement end point position 241 with the DEM file 111 and the Geoid file 112, the altitude from the ground surface is obtained, so the measurement start point normalized center vector 238 and the measurement end point normalized center axis vector The point where 243 intersects with Terrain 265 is obtained by correcting with DEM file 111. From the position of the point where it intersects with Terrain 265, the measurement start point center axis ground distance 240 and the measurement end point center axis ground distance 245 can be obtained. ,

FIG. 18 is a diagram showing the opening characteristics of the γ-ray scintillator. The sensitivity of the γ-ray scintillator is measured by γ-ray photons incident on the NaI156 crystal in FIG. 6 emitting light inside the crystal, so the relative positional relationship between the directivity shield 159 and NaI 156 and the geometry of the NaI 156 It is determined from the specifications and the gamma ray absorption characteristics of NaI 156. The γ-ray scintillator having the shape shown in FIG. 6 has a measurement range 187 of the γ-ray scintillator 3 shown in FIG. The measurement range 187 of the γ-ray scintillator 3 can be divided by the ground cell 264, and the sensitivity characteristic can be defined for each of them. The γ-ray scintillator opening characteristic data 260 viewed in the diameter direction of the measurement range 187 of the γ-ray scintillator 3 is an example of the γ-ray scintillator opening characteristic data 260 shown in FIG. The reason why the central part is slightly lower is derived from the fact that the crystal is cylindrical. The aperture characteristic data 260 shown in FIG. 16B is described in a table format to be stored in the computer.

In actual measurement while flying from an aircraft, for example, the measurement range 187 of the γ-ray scintillator 3 facing directly below moves by an aircraft movement amount 268 during the start of measurement during measurement. In FIG. 18B, the measurement range 266 of the measurement start point γ-ray scintillator moves during the measurement time, the aircraft movement amount 268 during the measurement start end, and moves to the measurement end point γ-ray scintillator measurement range 267. Therefore, the measurement range during the measurement of the γ-ray scintillator has a shape extended in the flight direction of the aircraft as shown in FIG. FIG. 18E shows the synthetic aperture characteristic data 269 taking into account the aircraft movement amount 268 between the start and end of measurement, and the synthetic aperture characteristic data 269 showing the characteristics in the major axis direction of FIG. 18C. This value is obtained by integrating the gamma ray scintillator opening characteristic data 260 in the aircraft moving direction for the measurement time.

Returning to FIG. 15, the processing blocks 254 and 255 will be described. Since the opening characteristic of each γ-ray scintillator is obtained in the description of FIG. 18, projection (footprint) on the ground surface is used for each γ-ray scintillator at each measurement point by using information in the measurement information secondary file 108. calculate. Here, the synthetic aperture characteristic data 269 is defined as corresponding to the measurement end point. Measurement end point position 241 Measurement end point normalized center axis vector 243 Measurement end point frame rotation angle 244 Measurement end point center axis ground surface distance and synthetic aperture characteristic data 269 in Fig. 18 from DEM file 111 The projection of the aperture characteristics of each γ-ray scintillator at each measurement point onto the ground surface is obtained as a value for each local cell 264 included in the footprint. The processing block 254 means that the above calculation is performed on all the γ-ray scintillator measurement values.

The processing of the processing block 256 in FIG. 15 is performed by calculating the measurement point and the γ-ray scintillator measurement value for each measurement point obtained in the processing blocks 254 and 255 and the projection value on the ground surface of the synthetic aperture characteristic data 269 for each γ-ray scintillator. Multiply and integrate all after normalizing with the measurement time.
For easier understanding, description will be made with reference to FIG.
While flying along the flight path 121, each γ-ray scintillator obtains respective measurement data for the measurement ranges 185 to 189 of the γ-ray scintillators 1 to 5. While flying on the flight path 121, the measurement is repeated as shown in FIG. 19 while overlapping the measurement ranges 185 to 189 of the γ-ray scintillators 1 to 5 with each other. The measured value obtained is the synthetic aperture characteristic data 269 as shown in processing block 255 and its description.
Is multiplied by the actual projection value on the ground surface and the measurement data, and is distributed to the local cell 264. As shown in FIG. 19, the processing of the processing block 256 integrates all measurement points and all γ-ray scintillator measurement data into the local cell 264 and normalizes the measurement time to obtain the radioactivity distribution. Can do.

  The radioactivity amount distribution information generating apparatus of the present invention can be generally used as an apparatus for measuring a radioactivity amount distribution from a moving body by a γ-ray scintillator assembly using a plurality of γ-ray scintillators. The platform carrying the gamma ray scintillator assembly may be a light aircraft, helicopter, or unmanned aircraft. Further, it may be a scanning mechanism installed away from a flat surface or a curved surface. In addition, although an example of a γ-ray scintillator has been shown as a sensor, as a technique for obtaining the distribution of sources of radiant energy such as electromagnetic waves that cannot use a condensing mechanism such as a lens or a reflecting mirror, medical and inspection measurements Can generally be used as equipment.

It is a figure which shows roughly the whole structure of the radioactive quantity distribution information generation apparatus of this invention. Example of route data of measurement route setting system of radioactivity distribution information generating device of the present invention It is a figure which shows the concept of the data acquisition of the flight control and (gamma) ray data automatic measurement system in the radioactive quantity distribution information generation apparatus shown in FIG. It is a figure which shows another concept of the data acquisition of the flight control and (gamma) ray automatic measurement system in the radioactivity amount distribution information generation apparatus shown in FIG. It is a figure which shows roughly the function structure of the radioactivity amount distribution information generation apparatus of this invention. It is a figure explaining the structure of the gamma ray scintillator of this invention. It is a figure explaining the structural example of the gamma ray scintillator aggregate | assembly of this invention. It is a figure explaining another structural example of the gamma ray scintillator aggregate of the present invention. It is a figure explaining the operation example of the data acquisition by the aircraft of the radioactive quantity distribution information generation apparatus of this invention. It is a figure which shows the structural example of the flight control and (gamma) data automatic measurement system of the radioactive quantity distribution information generation apparatus of this invention. It is a figure which shows the structural example of the radiation data acquisition plan file of the radioactive quantity distribution information generation apparatus of this invention. It is a figure which shows the example of a display apparatus of the flight control of the flight control and the gamma ray data automatic measurement system of the radioactive quantity distribution information generation apparatus of this invention. It is a figure which shows the processing flow of the flight control and the gamma ray data automatic measurement system of the radioactive quantity distribution information generation apparatus of this invention. . It is a figure which shows the structural example of the measurement information primary file of the radioactivity amount distribution information generation apparatus of this invention. It is a figure which shows the processing flow of the gamma ray data calibration and distribution calculation system of the radioactive quantity distribution information generation apparatus of this invention. . It is a figure which shows the structural example of the measurement information secondary file of the radioactive quantity distribution information generation apparatus of this invention. 3 is a diagram illustrating the ground surface measurement operation of the γ-ray scintillator of the radioactive quantity distribution information generating device of the present invention. It is a figure explaining the opening characteristic of the gamma ray scintillator of the radioactive quantity distribution information generation apparatus of this invention. It is a figure which shows the aspect for calculating the data acquisition by the gamma ray scintillator aggregate | assembly of a radioactive quantity distribution information generation apparatus of this invention, and calculating a radioactive quantity distribution. It is a figure explaining another structural example of the gamma ray scintillator aggregate | assembly of this invention. It is a figure explaining the structure of another directional shielding body about the structure of the gamma ray scintillator of this invention.

100 measurement route setting system
101 Radiation dose data acquisition plan file
102 Flight Control / γ-ray Data Automatic Measurement System
103 Measurement information primary file
104
γ-ray data measurement
105 DGPS measurement value
106 Measurement time
107
Sensor attitude measurement information
108
Measurement information secondary file
110 γ-ray data calibration and distribution calculation system
111 DEM files
112
Geoid file
113 Radiation dose distribution
115 graphic user interface system
116
the Internet
117
User
120
aircraft
121
Flight path
122 Measurement points
123 Central axis direction of γ-ray scintillator
124
Gamma ray scintillator footprint
125
Direction of travel
126
Previous measurement point
127 integration interval
130 Gamma ray scintillator assembly
131 Stabilizer
132
Hanging rope
140 to 142 function blocks
150 Aircraft position
151 Flight Route Distance
152 Measuring direction
155 γ-ray scintillator
156 NaI
157 Photoelectron detection counter
158 Side shield
159 Directional shield
160 Back shield
161 Gamma ray scintillator central axis
162 Directional characteristics
163 Gamma ray scintillator vertical plane
170 γ-ray scintillator 1
171 γ-ray scintillator 2
172 γ-ray scintillator 3
173 γ-ray scintillator 4
174 γ-ray scintillator 5
175 γ-ray scintillator 1 central axis
176 γ-ray scintillator 2 central axis
177 Gamma ray scintillator 3 Central axis
178 Gamma ray scintillator 4 Central axis
179 Gamma ray scintillator 5 Central axis
180 Gamma ray scintillator 1 deflection angle
181 Gamma ray scintillator 2 deflection angle
182 Gamma ray scintillator 4 deflection angle
183 Gamma ray scintillator 5 declination
184 Deflection center O
185 Measurement range of γ-ray scintillator 1
186 Measurement range of γ-ray scintillator 2
187 Measurement range of γ-ray scintillator 3
188 Measurement range of γ-ray scintillator 4
189 Measurement range of γ-ray scintillator 5
190 No.1 measurement coordinate file
191 Route No.2 measurement coordinate file
192 Channel No.m measurement coordinate file
193 Measurement tolerance
200 high-speed LED course indicator
201 Aircraft course deviation indicator
202 to 205 Numerical display windows 1 to 4
206 LED center indicator
207 LED left deviation display
208 LED right deviation display
210 DGPS
211 Flight control PC
212 γ-ray data automatic measurement control system
213 Position data
214 γ-ray measurement data
215 Time data
216 Attitude calibration data
217 Acquired data
218 Control commands
219 Floor hole for aerial camera
220 Measurement data header
221 γ-ray data part
222 Aircraft data part
223 Attitude sensor
224 Posture acquisition command and posture calibration data
225 Flight Navigation System
226 Data acquisition and recording system
227 Data by measurement point
228 Data by γ-ray scintillator
230 γ-ray scintillator ID
231 Measurement data ID
232 number of spectra
233 Measurement start date and time
234 Measurement end date and time
235 Measurement time
236 Measurement start point (latitude, longitude, altitude)
237 Measurement start point posture (pitch, yaw, roll)
238 Measurement start point normalized center axis vector t (XYZ)
239 Measurement start point frame rotation angle
240 Measurement start center axis ground distance
241 Measurement end point position (latitude, longitude, altitude)
242 Measurement end point posture (pitch, yaw, roll)
243 Measurement end point normalized center axis vector t (XYZ)
244 Measurement end point frame rotation angle
245 Measurement end point center axis ground distance
246 Total count
247 Spectrum band 0 count
248 Spectrum band 1 count
249 Spectral band 2 count
250 spectral band 3 count
251 Spectral band N count
252 to 257 function block
260 Gamma ray scintillator aperture characteristics data
261 Measurement date and time
262 position (latitude, longitude, altitude)
263 Attitude data
264 Ground cell
265 Terrain
266 Measurement start point Measurement range of γ-ray scintillator
267 Measurement end point Measurement range of γ-ray scintillator
268 Aircraft travel between measurement start and end
269 Synthetic aperture characteristics data

Claims (7)

The radiation measurement device measures the measurement area divided into multiple sub-areas at each of multiple measurement positions above the ground surface or in multiple directions along a continuously changing measurement position above the ground surface. Acquire multiple measurement information and store it in memory,
When storing each of the plurality of pieces of measurement information in the memory, the measurement position information, the measurement direction information, and the accompanying information including the measurement time when the measurement information is acquired are stored in the memory in association with the measurement information,
Identify the sub-area measured when the measurement information is acquired with reference to accompanying information including measurement position information, measurement direction information, and measurement time associated with the measurement information stored in the memory,
Storing the measurement information, the measurement position information, and the measurement direction information in a database in association with the identified sub-region;
An apparatus that refers to measurement information associated with the sub-region stored in the database and generates radiation dose distribution information on the ground surface by calculation.   The radiation dose measuring device includes a plurality of gamma ray scintillators facing a plurality of directions, and the plurality of gamma ray scintillators simultaneously measure at each of the plurality of measurement positions or along continuously changing measurement positions. The radiation dose distribution information generation device according to claim 1, wherein   The radiation dose measuring device is mounted on a flying object, and the plurality of gamma ray scintillators are directed to a plurality of directions from the flying object toward a ground surface including a vertical direction to perform measurement. Radiation dose distribution information generator.   The said flying object is an aircraft provided with a user interface which displays a deviation from a flight route or a flight route along a measurement position which passes through these measurement positions or changes continuously. 2. The radiation dose distribution information generation device according to 2.   The radiation dose distribution information generation device according to claim 2, wherein the measurement by the measurement device is performed while the flying object is flying at an altitude of 50 m or more and 2500 m or less from the ground surface.   For each sub-region of the plurality of sub-regions, the sub-region is measured a plurality of times by the plurality of gamma-ray scintillators, and the measured values are measured using the opening characteristics of the gamma-ray scintillator, the measurement position, and the measurement direction information. The surface radiation amount distribution information generation device according to claim 6, wherein the surface radiation activity distribution information is calculated by performing an integration operation. A plurality of γ-ray scintillators that are oriented in the direction of the axis and that have a central axis facing obliquely downward are arranged around an axis that extends from above to below, and the central axis and the axis of each of the plurality of γ-ray scintillators An imaging apparatus characterized in that the angles formed are substantially the same.