Method for assessing the quality of unmanned aerial systems for thermal imaging aerial survey based on extrapolation of the dependence of the detail of 8-bit thermal aerial images on flight altitude

Abstract

FIELD: measuring equipment.SUBSTANCE: according to the method for assessing the quality of thermal imaging aerial survey systems, the flight altitudes of the unmanned aerial system for thermal imaging aerial survey are selected to form the extrapolation base, thermal line targets are placed on the ground, their thermal contrast is determined by measuring the radiation temperatures of warm and cold lines, infrared aerial photography of the line targets is performed using thermal imaging aerial photography, and the aerial photographs are interpreted by a group of operators. Based on the results, the values of the linear resolution on the ground and the corresponding values of the coefficients of transmission of threshold thermal contrasts are determined based on measurements of the temperatures of pixels in images of warm dark and cold light strokes of the smallest recognized group of thermal stroke patterns in tone gradations from 0 to 255. A graph of the dependence of the terrain linear resolution on the altitude is constructed, a trend equation is determined by approximating the constructed graph with a third-order polynomial function, the trend is validated, and the predicted value of the linear resolution on the terrain for the predicted flight altitude is calculated without performing a flight of the unmanned aerial system for thermal imaging aerial photography at this altitude by extrapolating the trend, for which the value of the predicted altitude is substituted into the trend equation of the dependence of the terrain linear resolution on the altitude.EFFECT: increase in the accuracy of estimating the terrain linear resolution of thermal imaging aerial survey systems.6 cl, 2 dwg, 2 tbl

Description

[0001] The invention relates to technical physics and can be used for qualimetry of unmanned aerial systems (UAS) for thermal imaging aerial photography (TIA) that form images with a bit depth of 8 bits, during flight tests.

[0002] A known method from the prior art is for qualimetry of an unmanned aerial vehicle (UAV) of the copter type with an optical-electronic system (OES), which involves determining the linear resolution on the ground (patent for invention RU 2838121), which consists of placing a line target on the ground, performing aerial photography of the target using an unmanned aerial vehicle of the copter type equipped with an OES for observation with a varifocal lens (a lens with a variable focal length), with given values ​​of the focal length changed at equal intervals, and a constant altitude of aerial photography, decoding the obtained aerial photographs, calculating the linear resolution on the ground (LRT) using a conversion formula that relates the LRT to the width of the line in the group of lines recognized by the operator-decoder, the geometric altitude of the aerial photography and the focal length.The disadvantage of this method is that it does not allow the determination of the LRM at different UAV flight altitudes, since it assumes that flights are carried out at one constant altitude.

[0003] The closest analogue is the method for determining the LRM of infrared systems (IRS) of aerial reconnaissance (patents for invention RU 2836103), according to which, with a priori specified values ​​of the altitude and flight course of an aircraft, an aerial survey of areas of the terrain with placed line targets is carried out, which are sheets of sheet material made of iron, then, with a priori specified values ​​of the altitude and flight course of the aircraft, an aerial survey of areas of the terrain with placed line targets is carried out, the images are processed and the LRM IR is calculated as the arithmetic mean of the values ​​of the estimates obtained by all decoder operators for all images of the target, each of which is the minimum width of a line in recognized groups of lines, in which all lines are observed separately along their entire length, while simultaneously with the execution of an aerial survey, when the aircraft flies over the line target, the difference in the temperatures of the line of the line target and the background is measured,The linear resolution value of the infrared system is calculated taking into account the temperature of the target. The disadvantage of this method is that, due to its limited capabilities, it does not allow one to determine the LRM without performing flights at the required altitudes, and to establish a trend in the dependence of the LRM on the flight altitude in order to predict the LRM at the required flight altitudes by extrapolating the trend without performing flights at these altitudes.

[0004] The technical objective of the claimed invention is to develop an arsenal of methods for qualimetry of unmanned aerial systems for thermal imaging aerial photography that generate images with a bit depth of 8 bits.

[0005] The solution to the technical problem is achieved due to the fact that the method for assessing the quality of unmanned aerial systems for thermal imaging aerial photography based on the extrapolation of the dependence of the detail of 8-bit thermal aerial photographs on the flight altitude is characterized by the fact that

[0006] Determine the required flight altitudes ian unmanned aerial thermal imaging system that generates images with a bit depth of 8 bits, for compiling an extrapolation base, which is a set of pairs of flight altitude values ​​and corresponding values ​​of linear resolution on the ground, which form a series of dynamics of change in linear resolution on the ground from flight altitude, wherein the flight altitude changes with a lead step Δ, calculated in accordance with the expression: ,

[0007] where - the altitude at which it is necessary to perform a forecast of the linear resolution on the ground, H0 is the initial flight altitude, m is the number of members of the series that constitute the extrapolation base, where m≥5, then the value of the required flight altitudes is determined in accordance with the expression: , where i=0, 1, 2, …, m-1,

[0008] place thermal line targets on the ground, consisting of warm and cold lines and providing thermal contrast, taking into account the location of the lines along and across the direction of flight of the unmanned aerial system of thermal imaging aerial photography, forming images with a bit depth of 8 bits, and the absence of objects shading the surface of the area on which the targets are located,

[0009] carry out infrared aerial survey of thermal streak worlds using an unmanned aerial system for thermal imaging aerial survey at flight altitudes. i for given flight course values, so as to obtain at each flight altitude H iat least 20 aerial photographs obtained with angular oscillations of the unmanned aerial system for thermal imaging aerial photography not exceeding the permissible values, with the location of thermal line targets in the center of the aerial photograph or removed from the center in the direction of the horizontal and vertical sides of the aerial photograph at distances not exceeding 20% ​​of the transverse and longitudinal dimensions of the aerial photograph, respectively, while during the flight, the flight altitude is monitored i by measuring the geometric flight altitude of an unmanned aerial system for thermal imaging aerial photography using a laser altimeter or a radio altimeter,

[0010] Determine the thermal contrast ΔT0 of thermal line targets on the ground by measuring the radiation temperatures of warm and cold lines simultaneously with aerial photography at the moment of flight of an unmanned aerial thermal imaging system over the line targets, and performing further calculations in accordance with the formula: ,

[0011] whereT m IT с - results of brightness measurements of warm and cold strokes, respectively,

[0012] display the received aerial photographs on the screen of the automated interpretation workstation,

[0013] carry out the interpretation of thermal line target images on the obtained aerial photographs by at least three operator-decipherers, as a result of which each operator-decipherer determines the value of the linear resolution on the ground, which corresponds to the width of the warm dark or cold light line of the smallest group of lines, in which the lines are observed separately along their entire length in such a way that there is a visual perception of the difference in the level of gray tone between each warm dark line and the cold light lines adjacent to it along their entire length, and it is possible to count the number of lines in the group on the screen of the automated workstation of interpretation,

[0014] determine the final value of the linear resolution on the ground for each i-th flight altitude of the unmanned aerial system for thermal imaging aerial photography, as a result of averaging the estimates of the linear resolution on the ground for all operators-decipherers and all aerial photographs obtained at the i-th altitude, in accordance with the expression: ,

[0015] where - average value of linear resolution on the ground for flight altitude H i ; - the value of the linear resolution on the ground obtained by the r-th operator-decoder as a result of decoding the s-th image of the thermal line targets obtained at flight altitude H i ,r=1, …,R;s=1, …,S;R is the number of decoder operators, where R≥3;S is the number of thermal line target images obtained at flight altitude H i and subjected to decryption, with S≥20,

[0016] Calculate the threshold thermal contrast transfer coefficients , corresponding to the found values ​​of linear resolution on the ground , by determining the temperatures of pixels in the images of warm dark and cold light strokes of the smallest recognized group of thermal strokes in tone gradations from 0 to 255 using the graphical editor of the automated decryption workstation, and performing further calculations in accordance with the formulas:

[0017] , , ,

[0018] where - the average value of the threshold thermal contrast obtained from images obtained at flight altitude H i ; - the value of the threshold thermal contrast obtained by the r-th operator-decoder from the s-th image obtained at flight altitude H i ; , - average values ​​of the temperatures of the warm dark and cold light strokes of the smallest recognized group of strokes in tone gradations from 0 to 255, respectively, measured at the automated decoding workstation by the r-th operator-decoder using the s-th image obtained at flight altitude H i ,

[0019] plot a graph L(H) of the dependence of the linear resolution on the terrain on the height, taking into account the obtained coefficients of transmission of threshold contrasts at points with coordinates ( ;N i ) and determine the equation trend of the dependence of the linear resolution on the terrain on the height by approximating the constructed graph L(H) with a third-order polynomial function of the form ,

[0020] where - the values ​​of the parameters for approximating the graph line L(H) using the least squares method,

[0021] perform trend validation by evaluating the forecast accuracy using the mean relative forecast error indicator according to the expression:

[0022] ,

[0023] where - calculated value of linear resolution on the ground for height H i , calculated as a result of substitution into the trend equation valuesN i , however, if the validation results are obtained >5%, then the parameters of the trend equation approximation are refined and selected in such a way as to obtain a trend equation , ensuring the forecast accuracy corresponding to ≤5%,

[0024] Calculate the predicted value of the linear resolution on the ground for flight altitude by extrapolating the trend, for which a substitution is made into the trend equation height values .

[0025] The technical result achieved by the combination of features of the claimed invention consists in increasing the accuracy of estimating the linear resolution on the ground of thermal imaging aerial survey systems of unmanned aerial systems that form images with a bit depth of 8 bits, for a given flight altitude without performing flights at this altitude, by extrapolating the estimates of the linear resolution on the ground obtained when performing flights at other lower altitudes, and determining the coefficients of transfer of threshold thermal contrasts, which make it possible to take into account the temperature properties of aerial survey objects.

[0026] The implementation of the claimed invention is illustrated by the figures:

[0027] Figure 1 - Fragment of an aerial photograph showing thermal streak patterns.

[0028] Figure 2 - Graphs of the dependence of linear resolution on the terrain on flight altitude.

[0029] The essence of the invention consists in the following sequence of operations.

[0030] 1. Determination of required flight altitudes i A UAS TPVA, generating images with a bit depth of 8 bits, for forming an extrapolation base, which is a set of m pairs of flight altitude values ​​and the corresponding LRM values, which form a series of the dynamics of the change in LRM from the flight altitude, where the flight altitude changes with a lead step Δ, calculated in accordance with the expression:

[0031] ,

[0032] where - the altitude at which the LRM forecast must be performed, H0 - the initial flight altitude, m - the number of members of the series constituting the extrapolation base, where m ≥ 5. Then the value of the required flight altitudes is determined in accordance with the expression: , where i=0, 1, 2, …, m-1.

[0033] 2. Placement of thermal target charts on the ground, consisting of warm and cold charts and providing thermal contrast, taking into account the location of the charts along and across the direction of flight of the UAV TPVA, which forms images with an 8-bit resolution, and the absence of objects obscuring the surface of the area on which the charts are located.

[0034] 3. Infrared aerial photography of thermal streaks using UAV TPVA at flight altitudes i for given values ​​of the UAV TPVA flight course, in such a way as to obtain at each flight altitude H i at least 20 aerial photographs obtained with angular oscillations of the UAV TPVA not exceeding the permissible values, with the location of the thermal line targets in the center of the aerial photograph or removed from the center in the direction of the horizontal and vertical sides of the aerial photograph at distances not exceeding 20% ​​of the transverse and longitudinal dimensions of the aerial photograph, respectively, while during the flight, flight altitude monitoring is carried out iby measuring the geometric altitude of the UAV flight using a laser altimeter or a radio altimeter.

[0035] The flight course of the UAV TPVA is selected in such a way that the longitudinal and transverse axes of the thermal dash lines of the target are within ±10° from the lines perpendicular and parallel to the flight direction, respectively.

[0036] The lateral distance of the UAV TPVA path line from the location of the thermal line targets is selected in such a way that the images of the line targets fall in the center of the aerial photograph.

[0037] Flights are carried out at a meteorological visibility range of at least 10 km, as well as in the absence of clouds or the height of the lower edge of the cloud exceeding the flight altitude. m - 1 for 5%.

[0038] 4. Determining the thermal contrast ΔT0 of thermal line targets on the ground by measuring the radiation temperatures of warm and cold lines simultaneously with aerial photography at the moments of the UAV TPVA flight over the thermal line targets, and performing further calculations in accordance with the formula: , whereT т IT с - results of brightness measurements of warm and cold strokes, respectively.

[0039] 5. Displaying the obtained aerial photographs on the screen of the automated workstation (AWS) for interpretation.

[0040] 6. Interpretation of thermal line target images on the obtained aerial photographs by at least three operators-interpreters, as a result of which each operator-interpreter determines the LRM value, which corresponds to the width of a warm dark or cold light line of the smallest group of lines, in which the lines are observed separately along their entire length in such a way that there is a visual perception of the difference in the level of gray tone between each warm dark line and the neighboring cold light lines along their entire length, and it is possible to count the number of lines in the group on the screen of the automated workstation.

[0041] 7. Determination of the final LRM value for each i-th flight altitude of the UAV TPVA, as a result of averaging the LRM estimates for all operator-decipherers and all aerial photographs obtained at the i-th altitude, in accordance with the expression:

[0042] ,

[0043] where - average value of LRM for flight altitude H i ; - the LRM value obtained by the r-th operator-decoder as a result of decoding the s-th image of the thermal line charts obtained at flight altitude H i ,r=1, …,R;s=1, …,S;R is the number of decoder operators, where R≥3;S is the number of thermal line target images obtained at flight altitude H i and subjected to decryption, with S≥20.

[0044] 8. Determination of threshold thermal contrast transfer coefficients , corresponding to the found values ​​of LRM , by determining the temperatures of pixels in the images of warm dark and cold light strokes of the smallest recognized group of thermal strokes in tone gradations from 0 to 255 using the graphical editor of the ARM decryption, and performing further calculations in accordance with the formulas:

[0045] , , ,

[0046] where - the average value of the threshold thermal contrast obtained from images obtained at flight altitude H i ; - the value of the threshold thermal contrast obtained by the r-th operator-decoder from the s-th image obtained at flight altitude H i ; , - average values ​​of the temperatures of the warm dark and cold light strokes of the smallest recognized group of strokes in tone gradations from 0 to 255, respectively, measured at the automated decoding workstation by the r-th operator-decoder using the s-th image obtained at flight altitude H i .

[0047] 9. Plotting a graph of L(H) dependence of the LRM on the height, taking into account the obtained coefficients of transmission of threshold contrasts at points with coordinates ( ;N i ) and the definition of the equation trend of the dependence of LRM on height by approximating the constructed graph L(H) with a third-order polynomial function of the form

[0048] ,

[0049] where a0, a1, a2, a3 are the values ​​of the parameters for approximating the graph line L(H) using the least squares method,

[0050] 10. Perform trend validation by evaluating the forecast accuracy using the average relative forecast error indicator according to the expression: ,

[0051] where - calculated value of LRM for height H i , calculated as a result of substitution into the trend equation valuesN i .

[0052] If the validation results are >5%, then the parameters of the trend equation approximation are refined and selected in such a way as to obtain a trend equation , ensuring the forecast accuracy corresponding to ≤5%.

[0053] 11. Calculating the predicted value of LRM for flight altitude by extrapolating the trend, for which a substitution is made into the trend equation height values .

[0054] The technical result achieved by the combination of features of the claimed invention consists in increasing the accuracy of estimating the linear resolution on the ground of UAS thermal imaging aerial survey systems that form images with a bit depth of 8 bits for a given flight altitude without performing flights at this altitude by extrapolating the estimates of the linear resolution on the ground obtained when performing flights at other lower altitudes, and determining the coefficients of transfer of threshold thermal contrasts that make it possible to take into account the temperature properties of aerial survey objects.

[0055] Example 1. The effect of the claimed method was confirmed during flight tests of a quadcopter-type UAV with a thermal imaging system (TIS).

[0056] It is required to determine the LRM of the TPS at flight altitudes. ТЗ 1=500 m and N ТЗ 2=2000 m. UAS flights in the flight zone are permitted at altitudes of H<H ТЗ 2, as a result of which naN ТЗ2it is not possible to carry out flight experiments.

[0057] As a result of implementing the developed methodology, the following results were obtained:

[0058] 1. Before the UAS flight, the required flight altitudes were calculated to obtain an extrapolation base consisting of 5 LRM values ​​at 5 flight altitudes, i.e. m = 5. For simplicity, the notation H0 = H was introduced. ТЗ 1=500 m and =N ТЗ 2=2000 m.

[0059] The lead step is calculated: m.

[0060] The required flight altitude values ​​have been calculated:

[0061] m;

[0062] m;

[0063] m;

[0064] m.

[0065] 2. The UAS completed a flight at the specified altitudes H0, H1, H2, H3, and H4, during which the TPS conducted infrared aerial photography of thermal line targets, obtaining 20 aerial photographs at each altitude. Figure 1 shows a fragment of an aerial photograph obtained at flight altitude H1.

[0066] During the UAS flight, measurements were taken of the radiation temperatures of warm and cold streaks of thermal streaks on the ground and their thermal contrast was determined, which amounted to ΔT0=12.5°C.

[0067] 3. After the UAS flight, the images of thermal line targets were decoded on the decoding workstation, during which the LRMs were determined , , , , , measurements of the pixel temperatures of warm dark and cold light strokes in images of the smallest groups of strokes were carried out, and the values ​​of threshold thermal contrasts were calculated , , , , and coefficients of transmission of threshold thermal contrasts , , , , for flight altitudes H0, H1, H2, H3, H4, respectively. The decoding results are presented in Table 1.

[0068] Table 1 - Results of decoding images of thermal line patterns

[0069] Flight altitude Hi, m Threshold thermal contrast of the image, °C Threshold thermal contrast transfer coefficient LRM, m H0=500 =3,81 =0,305 =0,084 H1=800 =2,47 =0,198 =0,108 H2=1100 =1,77 =0,142 =0,139 H3=1400 =1,95 =0,156 =0,187 H4=1700 =2,57 =0,206 =0,263

[0070] 3. A graph of the dependence L(H) is plotted based on points with coordinates ( ;Н0), ( ;Н1), ( ;Н2), ( ;Н3), ( ;H4), a trend line was added using a third-order polynomial approximation function (Figure 2) and the trend equation was determined : .

[0071] 4. Trend validation completed , according to the results of which it was determined that the accuracy of the approximation was =2.3%, which indicates the possibility of using the trend equation for extrapolation.

[0072] 5. The predicted LRM value for the flight altitude has been calculated. =2000 m, which amounted to =0.363 m by extrapolating the trend, for which a substitution was made into the equation height values =2000 m.

[0073] To check the reliability of the obtained predicted value of LRM =0.363 m, a test flight of a flying laboratory based on an An-2 aircraft was carried out, during which an infrared aerial survey of thermal streak images was carried out using a TPS at an altitude of =2000 m and further determined by the LRM based on the results of interpretation of the obtained aerial photographs. The value of the LRM in this case was =0.356 m, which indicates a high reliability of the calculated LRM forecast: the convergence of the LRM forecast value for flight altitude with the true value of LRM at flight altitude amounted to 98.0%.

[0074] An alternative method for determining the LRM without flying at the required altitude involves using the formula for calculating the projection of a pixel onto the earth's surface (Ground Sampling Distance (GSD)) taking into account the Nyquist-Shannon-Kotelnikov theorem: ,

[0075] whereL GSD _ N- LRM according to the GSD criterion taking into account the Nyquist-Shannon-Kotelnikov theorem; a is the linear size of the pixel of the matrix photodetector of the TPS; f' ​​is the focal length of the TPS lens.

[0076] Calculated value of the LRM TPS for flight altitude =2000 m was L GSD _ N =0.303 m (calculated taking into account the values ​​of the TPS parameters: a=2.5 µm, f'=33 mm).

[0077] The results of the comparison of the obtained LRM TPS estimates are presented in Table 2.

[0078] Table 2 - Comparison of predicted, calculated and experimental estimates of the LRM TPS

[0079] Method of assessing LRM LRM, m Number of flights at altitude Convergence of estimates, % Experimental evaluation of the LRM based on the results of the flight at the required altitude 0,356 1 Predictive assessment of the LRM when implementing the declared method without performing a flight at the required altitude 0,363 0 98,0 Estimated estimate of LRM LGSD_N 0,303 0 68,7 Increase in the accuracy of the forecast estimate relative to the calculated estimate LGSD_N, % 29,3

[0080] The data in Table 2 demonstrate the effectiveness of the proposed method for predictive LRM estimation using a quadcopter-type UAS TPS as an example. Specifically, the proposed method improves the accuracy of LRM determination for a given flight altitude without the need to fly at that altitude. The accuracy of the predictive LRM estimate increased by 29.3% compared to the calculated one. Furthermore, the predictive estimation method reduces the number of flights required for LRM estimation by eliminating the need to fly at the required altitude. At the same time, the high reliability of the predictions is maintained: predictive LRM estimates obtained without flying at the required altitude demonstrate 98.0% convergence with experimental estimates obtained at that altitude.

Claims

1. A method for assessing the quality of unmanned aerial systems for thermal imaging aerial photography based on the extrapolation of the dependence of the detail of 8-bit thermal aerial photographs on the flight altitude, characterized by the fact that determine the required flight altitudes i an unmanned aerial thermal imaging system that generates images with a bit depth of 8 bits, for compiling an extrapolation base, which is a set of pairs of flight altitude values ​​and corresponding values ​​of linear resolution on the ground, which form a series of dynamics of change in linear resolution on the ground from flight altitude, wherein the flight altitude changes with a lead step Δ, calculated in accordance with the expression: , Where – the altitude at which it is necessary to perform a forecast of the linear resolution on the ground, H0 – the initial flight altitude, m – the number of members of the series that constitute the extrapolation base, where m≥5, then the value of the required flight altitudes is determined in accordance with the expression: , where i=0, 1, 2, …, m–1, thermal line targets are placed on the ground, consisting of warm and cold lines and providing thermal contrast, taking into account the arrangement of the lines along and across the direction of flight of the unmanned aerial thermal imaging system that forms images with a bit depth of 8 bits, and the absence of objects that obscure the surface of the area on which the targets are located, perform infrared aerial photography of thermal streaks using an unmanned aerial system for thermal imaging aerial photography at flight altitudes i for given flight course values ​​in such a way as to obtain at each flight altitude H iat least 20 aerial photographs obtained with angular oscillations of the unmanned aerial system for thermal imaging aerial photography not exceeding the permissible values, with the location of thermal line targets in the center of the aerial photograph or removed from the center in the direction of the horizontal and vertical sides of the aerial photograph at distances not exceeding 20% ​​of the transverse and longitudinal dimensions of the aerial photograph, respectively, while during the flight, the flight altitude is monitored i by measuring the geometric flight altitude of an unmanned aerial system for thermal imaging aerial photography using a laser altimeter or a radio altimeter, The thermal contrast ΔT0 of thermal line targets on the ground is determined by measuring the radiation temperatures of warm and cold lines simultaneously with aerial photography at the moment of flight of an unmanned aerial system for thermal aerial photography over the line targets and performing further calculations in accordance with the formula: , whereT m IT с – the results of measurements of the brightness of warm and cold strokes, respectively, display the obtained aerial photographs on the screen of the automated interpretation workstation, deciphering of thermal line target images on the obtained aerial photographs is performed by at least three operator-decipherers, as a result of which each operator-decipherer determines the value of the linear resolution on the ground, which corresponds to the width of a warm dark or cold light line of the smallest group of lines, in which the lines are observed separately along their entire length in such a way that there is a visual perception of the difference in the level of gray tone between each warm dark line and the cold light lines adjacent to it along their entire length, and it is possible to count the number of lines in the group on the screen of the automated deciphering workstation, determine the final value of the linear resolution on the ground for each i-th flight altitude of the unmanned aerial system for thermal imaging aerial photography as a result of averaging the estimates of the linear resolution on the ground for all operators-decipherers and all aerial photographs obtained at the i-th altitude, in accordance with the expression: , Where – average value of linear resolution on the ground for flight altitude H i ; – the value of the linear resolution on the ground obtained by the r-th operator-decoder as a result of decoding the s-th image of the thermal line targets obtained at flight altitude H i ,r=1, ...,R;s=1, ...,S;R is the number of decoder operators, where R≥3;S is the number of thermal line target images obtained at flight altitude H i and subjected to decryption, with S≥20, calculate the coefficients of transmission of threshold thermal contrasts , corresponding to the found values ​​of linear resolution on the ground , by determining the temperatures of pixels in the images of warm dark and cold light strokes of the smallest recognized group of thermal strokes in tone gradations from 0 to 255 using the graphical editor of the automated decryption workstation and performing further calculations in accordance with the formulas: , , , Where – the average value of the threshold thermal contrast obtained from images obtained at flight altitude H i ; – the value of the threshold thermal contrast obtained by the r-th operator-decoder from the s-th image obtained at flight altitude H i ; , – average values ​​of the temperatures of the warm dark and cold light strokes of the smallest recognized group of strokes in tone gradations from 0 to 255, respectively, measured at the automated decoding workstation by the r-th operator-decoder using the s-th image obtained at flight altitude H i , construct a graph L(H) of the dependence of the linear resolution on the terrain on the height, taking into account the obtained coefficients of transmission of threshold contrasts at points with coordinates ( ;N i ) and determine the equation trend of the dependence of the linear resolution on the terrain on the height by approximating the constructed graph L(H) with a third-order polynomial function of the form , Where – the values ​​of the parameters of the approximation of the graph line L(H) by the least squares method, perform trend validation by assessing the forecast accuracy using the mean relative forecast error in accordance with the expression: , Where – calculated value of linear resolution on the ground for height H i , calculated as a result of substitution into the trend equation valuesN i , however, if the validation results are obtained >5%, then the parameters of the trend equation approximation are refined and selected in such a way as to obtain a trend equation , ensuring the forecast accuracy corresponding to ≤5%, calculate the predicted value of linear resolution on the ground for flight altitude by extrapolating the trend, for which a substitution is made into the trend equation height values .

2. The method according to paragraph 1, characterized in that a Thermalert 4.0 radiation thermometer is used as a means for measuring the radiation temperatures of warm and cold lines of thermal line charts on the ground.

3. The method according to paragraph 1, characterized in that the warm strokes of the thermal worlds are made of aluminum plates painted black.

4. The method according to paragraph 1, characterized in that the thermal line chart consists of warm lines, made in the form of metal plates laid out on the earth's surface at specified distances, and cold lines, which are areas of the earth's surface between the laid out metal plates.

5. The method according to paragraph 1, characterized in that the cold strokes of the thermal worlds are made of polished aluminum plates.

6. The method according to paragraph 1, characterized in that a satellite navigation system is used as a means for measuring the geometric flight altitude of the aircraft.

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