CN115173974A - Downlink interference calculation method based on space resource database and contour line interpolation - Google Patents

Abstract

The invention discloses a downlink interference calculation method based on a space resource database and contour line interpolation, which is used for calculating downlink interference during communication between two satellites and comprises the following specific steps: an earth station location marker; establishing a target table; acquiring beam contour lines of a transmitting beam of an interference satellite and a transmitting beam of a disturbed satellite from GIMS map data in graphic interference system software GIMS developed by the International telecommunication Union, and performing interpolation based on the beam contour lines; calculating a transmit beam gain value at the earth station; calculating a grid point closest to the marking point, and taking a transmission beam gain value of the grid point as a transmission beam gain value at the earth station; an interference value of a downlink beam from the satellite to the earth station is calculated. According to the method, the beam gain contour line of the satellite is obtained by interpolating the GIMS contour line in combination with the graphics problem, the beam gain of the position of the earth station can be rapidly and accurately obtained, and the speed and the accuracy of link interference analysis are effectively improved.

Description

Downlink interference calculation method based on space resource database and contour line interpolation

Technical Field

The invention relates to the technical field of wireless communication, in particular to a downlink interference calculation method based on a space resource database and contour line interpolation.

Background

Current methods for analyzing link interference between satellite communication networks mainly use interference calculation methods specified in section B3 of the "program rules" (ROP) of the International Telecommunication Union (ITU). The method for analyzing the interference between satellites in the same frequency band in ROP is to calculate the noise temperature N of the system_tot Calculating the carrier-to-noise ratio C/N from the noise temperature_tot And determining the required carrier-to-interference ratio (C/I) based on the carrier-to-noise ratio factor_m I.e., the protection criteria for the carrier-to-interference ratio, interference is deemed acceptable when less than or equal to the protection criteria, and otherwise is deemed detrimental. For the inter-satellite interference of different co-frequencies, the condition of inter-carrier frequency offset is mostly considered, and an interference adjustment factor (or bandwidth dominance factor) is calculated. The existing interference analysis method has the following defects:

1) In the existing interference analysis method, a calculation algorithm for determining satellite beam gain is not available, and when a local sphere station is not located on a beam profile contour line, the beam gain value can not be accurately calculated, so that the interference analysis has errors;

2) In the existing interference analysis method, the calculated physical quantity is too single, different physical quantities are different in aspect of representation, and the representation of the single physical quantity on interference is too single;

3) The existing interference analysis method is difficult to realize automatic and rapid calculation of beam gain, and when the number of calculated links is large, the calculation amount is too large due to difficult automatic calculation, and the result is inaccurate.

Disclosure of Invention

The invention discloses a downlink interference calculation method based on a space resource database and contour line interpolation, aiming at the problem that the existing satellite communication network downlink interference analysis method does not consider satellite beam gain and overlarge calculation amount, so as to improve the accuracy of interference analysis and the practicability of space resource storage.

The invention discloses a downlink interference calculation method based on a space resource database and contour line interpolation, which is used for calculating downlink interference during communication between two satellites, wherein the two satellites are divided into an interference satellite and a disturbed satellite, and the method comprises the following specific steps:

s1, marking the position of the earth station. Marking earth stations corresponding to two satellites on a map, and acquiring position information of each earth station; defining a two-dimensional array for storing location information for each earth station: the two-dimensional array is represented as,

Loc＝[[‘ID1’,longitude,latitude],[‘ID2’,longitude,latitude],……]；

and S2, establishing a target table. The target table is used for storing the interference physical quantity obtained by final calculation. The target table contains a list of beams and beam directions, wherein a beam is transmitted by one satellite and used for communicating with the earth station (interference can be generated between the co-directional beams of two different satellites);

and S3, obtaining beam contour lines of the transmitting beam of the interference satellite and the transmitting beam of the disturbed satellite from GIMS map data in graphic interference system software GIMS developed by the International telecommunication Union, and carrying out interpolation based on the beam contour lines to obtain the transmitting beam gain of the disturbed satellite to the disturbed earth station and the transmitting beam gain of the interference satellite to the disturbed earth station.

S31, uniformly gridding and dividing the GIMS map data according to 0.125 degrees to obtain a plurality of grids and grid points: the grid points are four vertexes of one grid;

s32, acquiring longitude and latitude of each grid point on the GIMS map data, wherein the longitude and latitude is recorded as (long, lat) and the unit is demerees;

s33, on the GIMS map data, selecting the beam contour line with the maximum corresponding beam gain value and the beam contour line with the minimum corresponding beam gain value from all the beam contour lines, respectively and randomly selecting 3 sample points on the two beam contour lines, and storing the longitude and latitude and the gain value of each sample Point into a Point array, wherein the Point array is represented as:

Point＝[[long_1,lat_1,gain_1],…,[long_i,lat_i,gain_i]]；

s34, calculating the distances between all the sample points and the grid points through the longitude and latitude (long, lat) of the grid points obtained in the step S32 and the Point array obtained in the step S33, wherein the distance between the ith sample Point and a certain grid Point is represented as d _ i;

s35, calculating the gain of the emission beam at the corresponding grid Point by using the Point array obtained in the step S33 and the distance calculated in the step S34, wherein the calculation formula is as follows:

wherein, gain _ i is the transmission beam gain at the ith sample point, and n is the number of sample points.

And S4, calculating a transmitting beam gain value at the earth station. Recording the position of the earth station as a mark point, calculating a grid point closest to the mark point, recording a transmission beam gain value of the grid point, and taking the transmission beam gain value of the grid point as a transmission beam gain value at the earth station;

s5, calculating an interference value of a downlink beam from the satellite to the earth station, wherein the calculation process comprises the following steps:

firstly, searching the beam names of downlink beams of a disturbed satellite and an interference satellite in a satellite transponder table grp of a satellite space resource database (SRS), searching corresponding satellite transponder numbers according to the beam names, searching all corresponding earth stations and all carriers according to the searched satellite transponder numbers, calculating a transmitting beam gain value at the earth station according to the step S4, and determining the transmitting beam gain value at the searched earth station;

identifying a transmitting earth station of the interfered satellite as an interfered earth station and identifying a transmitting earth station of the interfering satellite as an interfering earth station; longitude of the geographic position of the interfered earth station is long _ es (degrees), latitude is lat _ es (degrees), the diameter of the antenna of the interfered earth station is D (m), the antenna efficiency is eff, the main lobe Gain of the antenna of the earth station is Gmax, the beam Gain of the interfered satellite of the position of the interfered earth station is Gain1 (dBi), the beam Gain of the interfering satellite of the position of the interfered earth station is Gain2 (dBi), the orbit position of the interfered satellite is long _ sat (degrees), the transmitting power of the feed antenna of the interfered satellite is P1 (dBW), the transmitting frequency of the feed antenna of the interfered satellite is f1 (MHz), the orbit position of the interfering satellite is long _ sat2 (degrees), the transmitting power of the feed antenna of the interfering satellite is P2 (dBW), and the transmitting frequency of the feed antenna of the interfering satellite is f2 (MHz). The carrier bandwidth of the disturbed satellite is B in dB, and the system noise temperature of the disturbed earth station is noise in K.

Calculating the space geometric relationship among the interference satellite, the disturbed satellite and the corresponding earth stations, wherein the space geometric relationship specifically comprises the following steps:

calculating a cosine value cos (ang 1) of an angle ang1 between the disturbed satellite and the disturbed earth station through the disturbed satellite orbit position long _ sat, the longitude and latitude (long _ es, lat _ es) of the disturbed earth station, and the calculation formula is as follows:

cos(ang1)＝cos(lat_es)×cos(long_sat-long_es)，

calculating the distance d1 between the disturbed earth station and the disturbed satellite, wherein the unit is km, and the calculation formula is as follows:

calculating a cosine value cos (ang 2) of an angle ang2 between the disturbed satellite and the disturbed earth station through the longitude long _ sat2 of the disturbed satellite and the longitude and latitude (long _ es, lat _ es) of the disturbed earth station, wherein the calculation formula is as follows:

cos(ang2)＝cos(lat_es)×cos(long_sat2-long_es)，

calculating the distance d2 between the interference satellite and the interfered earth station, wherein the unit is km, and the calculation formula is as follows:

calculating the geocentric angle theta _ g of the two satellites by using the orbit position of the interfered satellite as long _ sat and the orbit position of the interfering satellite as long _ sat2, wherein the unit is degrees, and the calculation formula is as follows:

theta_g＝|long_sat-long_sat2|，

calculating the apical angle theta _ t of the disturbed satellite and the interference satellite relative to the disturbed earth station, wherein the unit is degrees, and the calculation formula is as follows:

calculating the free space transmission loss v _ los8 of the electromagnetic wave from the disturbed satellite to the disturbed earth station, wherein the unit is dB, and the calculation formula is as follows:

v_loss＝20(logf1+log d1)+32.45，

calculating the free space transmission loss I _ loss of the electromagnetic wave from the interference satellite to the interfered earth station, wherein the unit is dB, and the calculation formula is as follows:

I_loss＝20(logf2+log d2)+32.45，

calculating the gain v _ gain of an on-axis receiving antenna of the disturbed earth station in unit dBi according to the diameter D of the antenna of the disturbed earth station, the frequency f1, the antenna efficiency eff and the optical speed c, wherein the calculation formula is as follows:

where pi is a constant pi.

Calculating the off-axis receiving antenna gain I _ gain of the disturbed earth station through the diameter D of the antenna of the disturbed earth station, the frequency f1, the antenna efficiency eff, the optical speed c and the apical angle theta _ t, wherein the unit is dBi: in the determination of the receiving antenna radiation pattern of the disturbed earth station, the receiving antenna gain calculation process of the disturbed earth station comprises,

calculating the wavelength lambda of the electromagnetic wave emitted by the interference satellite, wherein the unit is m, and the calculation formula is as follows:

lambda＝c/f2，

calculating the aperture gain G _ peak of the disturbed earth station antenna according to the diameter D of the disturbed earth station antenna, the antenna efficiency eff and the wavelength lambda, wherein the unit is dBi, and the calculation formula is as follows:

calculating the half-power beam width theta-3 db of the interfered earth station antenna according to the diameter D and the wavelength lambda of the interfered earth station antenna, wherein the calculation formula is as follows:

calculating the off-axis gain I _ gain of the interfered earth station antenna with the unit of dB through the diameter D of the interfered earth station antenna, the wavelength lambda, the antenna aperture gain G _ peak, the half-power beam width theta _3dB and the top center angle theta _ t when the unit is dB

In time, the calculation formula of the off-axis gain I _ gain of the interfered earth station antenna is as follows:

when the temperature is higher than the set temperature

In time, the calculation formula of the off-axis gain I _ gain of the antenna of the disturbed earth station is as follows:

I_gian＝29-25log(tehta_t)，

when theta _ t is larger than 36.4, the calculation formula of the disturbed earth station antenna off-axis gain I _ gain is as follows:

I_gian＝-10，

when the radiation pattern of the receiving antenna of the disturbed earth station is unknown, the calculation process of the receiving antenna gain of the disturbed earth station comprises the following steps of calculating the wavelength lambda of electromagnetic waves emitted by an interference satellite, wherein the unit is m, and the calculation formula is as follows:

lambda＝c/f2，

calculating a first side lobe gain G1 of an antenna radiation directivity diagram through the diameter D and the wavelength lambda of the interfered earth station antenna, wherein the unit is dBi, and the calculation formula is as follows:

calculating the main lobe width theta _ m of the interfered earth station antenna according to the diameter D of the interfered earth station antenna, the main lobe gain Gmax of the antenna, the wavelength lambda and the first side lobe gain G1, wherein the unit is degrees, and the calculation formula is as follows:

through the diameter D of the interfered earth station antenna, the width theta _ r of a nearby lobe of the interfered earth station antenna is calculated, the unit is a diversity, the nearby lobe of the interfered earth station antenna is a side lobe closest to a main lobe of the interfered earth station antenna, and the calculation formula is as follows:

calculating the off-axis gain I _ gain of the interfered earth station relative to the interference satellite in dBi according to the diameter D of the antenna of the interfered earth station, the wavelength lambda, the first boundary value theta _ m of the off-axis angle, the second boundary value theta _ r of the off-axis angle and the top center angle theta _ t when the unit is dBi

If 0 < theta _ t < theta _ m, the calculation formula is as follows:

if theta _ m is less than or equal to theta _ t and less than theta _ r, the calculation formula is as follows:

I_gain＝G1，

if theta _ r is not more than theta _ t < 48, the calculation formula is as follows:

I_gain＝32-25log(theta_t)，

if 48 is equal to or less than theta _ t < 180, the calculation formula is as follows:

I_gian＝-10，

when in use

When the temperature of the water is higher than the set temperature,

if 0 < theta _ t < theta _ m, the formula is:

for example as body

The calculation formula is as follows:

I_gain＝G1，

for example as body

The calculation formula is as follows:

if 48 is equal to or less than theta _ t < 180, the calculation formula is as follows:

calculating interference physical quantity, wherein the interference physical quantity comprises a carrier-to-noise ratio CtON of a signal transmitted to the interfered earth station by an interfered satellite, interference power I of an interference signal of the interfered satellite to the interfered earth station, a carrier-to-interference ratio CtI, a carrier-to-interference plus noise ratio CtON _ I, an interference-to-noise ratio ItoN and an equivalent noise temperature increment percentage DTtot,

calculating the system noise N of the disturbed earth station in dB according to the calculation formula:

N＝10log(noise)-228.6+10logB，

calculating the carrier power C of a signal transmitted by a disturbed satellite to a disturbed earth station by the disturbed satellite transmitting power P1, the disturbed satellite beam Gain Gain1, the receiving antenna Gain upsilon _ Gain and the free space transmission loss upsilon _ loss, wherein the unit is dB, and the calculation formula is as follows:

C＝P1+Gain1+υ_gain-υ_loss，

calculating the interference power I of an interference signal of the interference satellite to a disturbed earth station by the transmission power P2 of the interference satellite, the beam Gain2 of the interference satellite, the Gain I _ Gain of a receiving antenna and the spatial transmission loss I _ loss, wherein the unit is dB, and the calculation formula is as follows:

I＝P2+Gain2+I_gain-I_loss，

calculating the carrier-to-noise ratio CtoN of a signal transmitted to the interfered earth station by the interfered satellite in dB, wherein the calculation formula is as follows:

GtoN＝C-N，

calculating the carrier-to-interference ratio CtoI with the unit of dB, wherein the calculation formula is as follows:

CtoI＝C-I，

calculating the carrier to interference plus noise ratio CtoN _ I with the unit of dB, wherein the calculation formula is as follows:

CtoN_I＝C-10log(10^N/10 +10^I/10 )，

the interference to noise ratio ItoN is calculated in dB, and is calculated as:

ItoN＝I-N，

calculating the equivalent noise temperature increment percentage DTtot of the satellite link by using the interference-to-noise ratio ItoN, wherein the unit is dB, and the calculation formula is as follows:

calculating interference physical quantity of all communication links corresponding to a plurality of earth stations and different communication links corresponding to different earth stations under a satellite transmitting beam; and for the transmitting beam of the interference satellite and the transmitting beam of the interfered satellite, selecting the worst value of each interference physical quantity from the interference physical quantities of all the communication links obtained by calculation, taking the worst value as a downlink interference calculation result between the two beams, storing the downlink interference calculation result into a target table, and displaying the interference calculation result. For the interference physical quantities CtoN, ctoI and CtoN _ I, comparing the interference calculation result with a threshold, and displaying the target table as green when the interference calculation result is not lower than the threshold; and when the interference calculation result is lower than the threshold, displaying the target table as red to indicate that the interference is harmful. For interference physical quantities ItoN and DTtoT, comparing an interference calculation result with a threshold, and displaying a target table as green when the interference calculation result is not higher than the threshold; and when the interference calculation result is higher than the threshold, displaying the target table as red to indicate that the interference is harmful.

The invention has the beneficial effects that:

compared with the prior art, the invention has the remarkable advantages that: and a beam gain contour line dense in the satellite is obtained by interpolating the GIMS contour line in combination with a graphics problem, so that the beam gain of the position of the earth station can be rapidly and accurately obtained, and the speed and the accuracy of link interference analysis are effectively improved.

Drawings

Fig. 1 is a schematic diagram of the distance between a random sample point for calculating the gain of a grid point and a grid point to be calculated according to the present invention;

fig. 2 is a schematic diagram of the spatial geometry of the downlink of the present invention.

Detailed Description

For a better understanding of the present disclosure, an example is given here.

Fig. 1 is a schematic diagram of the distance between a random sample point for calculating the gain of a grid point and a grid point to be calculated according to the present invention; fig. 2 is a schematic diagram of the spatial geometry of the downlink of the present invention.

The invention discloses a downlink interference calculation method based on a space resource database and contour line interpolation, which is used for calculating downlink interference during communication between two satellites, wherein the two satellites are divided into an interference satellite and a disturbed satellite, and the method comprises the following specific steps:

and S1, marking the position of the earth station. Marking earth stations corresponding to the two satellites on the map, and acquiring position information of each earth station; defining a two-dimensional array for storing location information for each earth station: the two-dimensional array is represented as,

Loc＝[[‘ID1’,longitude,latitude],[‘ID2’,longitude,latitude],……]；

and S2, establishing a target table. The target table is used for storing the interference physical quantity obtained by final calculation. The target table contains a list of beams and beam directions, wherein a beam is transmitted by one satellite and used for communicating with the earth station (interference can be generated between the co-directional beams of two different satellites);

and S3, obtaining beam contour lines of the transmitting beam of the interference satellite and the transmitting beam of the disturbed satellite from GIMS map data in graphic interference system software GIMS developed by the International telecommunication Union, and carrying out interpolation based on the beam contour lines to obtain the transmitting beam gain of the disturbed satellite to the disturbed earth station and the transmitting beam gain of the interference satellite to the disturbed earth station.

S31, carrying out uniform gridding division on the GIMS map data according to 0.125 degrees to obtain a plurality of grids and grid points: the grid points are four vertexes of one grid;

s32, acquiring longitude and latitude of each grid point on the GIMS map data, wherein the longitude and latitude is recorded as (long, lat) and the unit is demerees;

s33, on the GIMS map data, selecting a beam contour line with the maximum corresponding beam gain value and a beam contour line with the minimum corresponding beam gain value from all the beam contour lines, respectively randomly selecting 3 sample points on the two beam contour lines, and storing the longitude, the latitude and the gain value of each sample Point into a Point array, wherein the Point array is represented as follows:

Point＝[[long_1,lat_1,gain_1],…,[long_i,lat_i,gain_i]]；

s34, calculating distances between all sample points and the grid Point through the longitude and latitude (long, lat) of the grid Point obtained in step S32 and the Point array obtained in step S33, where a distance between the ith sample Point and a certain grid Point is denoted as d _ i, as shown in fig. 2;

s35, calculating the gain of the emission beam at the corresponding grid Point by using the Point array obtained in the step S33 and the distance calculated in the step S34, wherein the calculation formula is as follows:

wherein, gain _ i is the transmission beam gain at the ith sample point, and n is the number of sample points.

And S4, calculating a transmitting beam gain value at the earth station. Recording the position of the earth station as a mark point, calculating a grid point closest to the mark point, recording a transmission beam gain value of the grid point, and taking the transmission beam gain value of the grid point as a transmission beam gain value at the earth station;

s5, calculating an interference value of a downlink beam from the satellite to the earth station, wherein the calculation process comprises the following steps:

firstly, searching the beam names of downlink beams of a disturbed satellite and an interference satellite in a satellite transponder table grp of a satellite space resource database (SRS), searching corresponding satellite transponder numbers according to the beam names, searching all corresponding earth stations and all carriers according to the searched satellite transponder numbers, calculating a transmitting beam gain value at the earth station according to the step S4, and determining the transmitting beam gain value at the searched earth station;

identifying the transmitting earth station of the victim satellite as a victim earth station and the transmitting earth station of the aggressor satellite as an aggressor earth station, as shown in FIG. 2; longitude of the geographical position of the interfered earth station is long _ es (degrees), latitude is lat _ es (degrees), the diameter of the antenna of the interfered earth station is D (m), the antenna efficiency is elf, the main lobe Gain of the antenna of the earth station is Gmax, the beam Gain of the interfered satellite of the position of the interfered earth station is Gain1 (dBi), the beam Gain of the interfering satellite of the position of the interfered earth station is Gain2 (dBi), the orbit position of the interfered satellite is long _ sat (degrees), the transmitting power of the feeding antenna of the interfered satellite is P1 (dBW), the transmitting frequency of the feeding antenna of the interfered satellite is f1 (MHz), the orbit position of the interfering satellite is long _ sat2 (degrees), the transmitting power of the feeding antenna of the interfering satellite is P2 (dBW), and the transmitting frequency of the feeding antenna of the interfering satellite is f2 (MHz). The carrier bandwidth of the disturbed satellite is B in dB, and the system noise temperature of the disturbed earth station is noise in K.

The corresponding relation between the parameters and the data in the SRS database is as follows:

table 1 data mapping table

Input item	SRS data item
		long_es	Long _ dec of e _ as _ stn table
lat_es	Lat _ dec of e _ as _ stn table
		D	Ant _ Diam of e _ ant table
Gmax	Gain of e _ as _ stn table
		long_sat、long_sat2	Long _ nom of geo table
f1、f2	Freq _ carr of carrier _ fr table
		P1、P2	Pep _ min of emiss Table
noise	Noise _ t of e _ as _ stn table
		B	Bdwdth of grp table

Calculating the space geometric relationship among the interference satellite, the disturbed satellite and the corresponding earth stations, wherein the space geometric relationship specifically comprises the following steps:

calculating a cosine value cos (ang 1) of an angle ang1 between the disturbed satellite and the disturbed earth station through the disturbed satellite orbit position long _ sat, the longitude and latitude (long _ es, lat _ es) of the disturbed earth station, and the calculation formula is as follows:

cos(ang1)＝cos(lat_es)×cos(long_sat-long_es)，

calculating the distance d1 between the disturbed earth station and the disturbed satellite, wherein the unit is km, and the calculation formula is as follows:

calculating a cosine value cos (ang 2) of an angle ang2 between the disturbed satellite and the disturbed earth station through the longitude long _ sat2 of the disturbed satellite and the longitude and latitude (long _ es, lat _ es) of the disturbed earth station, wherein the calculation formula is as follows:

cos(ang2)＝cos(lat_es)×cos(long_sat2-long_es)，

calculating the distance d2 between the interference satellite and the interfered earth station, wherein the unit is km, and the calculation formula is as follows:

calculating the geocentric angle theta _ g of the two satellites by using the orbit position of the interfered satellite as long _ sat and the orbit position of the interfering satellite as long _ sat2, wherein the unit is degrees, and the calculation formula is as follows:

theta_g＝|long_sat-long_sat2|，

calculating the top center angle theta _ t of the disturbed satellite and the interference satellite relative to the disturbed earth station, wherein the unit of the top center angle theta _ t is degrees, and the calculation formula is as follows:

calculating the free space transmission loss v _ loss of the electromagnetic wave from the disturbed satellite to the disturbed earth station, wherein the unit is dB, and the calculation formula is as follows:

v_loss＝20(log f1+log d1)+32.45，

calculating the free space transmission loss I _ loss of the electromagnetic wave from the interference satellite to the interfered earth station, wherein the unit is dB, and the calculation formula is as follows:

I_loss＝20(log f2+log d2)+32.45，

calculating the gain v _ gain of an on-axis receiving antenna of the disturbed earth station in unit dBi according to the diameter D of the antenna of the disturbed earth station, the frequency f1, the antenna efficiency eff and the optical speed c, wherein the calculation formula is as follows:

where pi is a constant pi.

Calculating the off-axis receiving antenna gain I _ gain of the disturbed earth station through the diameter D of the antenna of the disturbed earth station, the frequency f1, the antenna efficiency eff, the optical speed c and the top center angle theta _ t, wherein the unit is dBi: in the determination of the receiving antenna radiation pattern of the disturbed earth station, the receiving antenna gain calculation process of the disturbed earth station comprises,

calculating the wavelength lambda of the electromagnetic wave emitted by the interference satellite, wherein the unit is m, and the calculation formula is as follows:

lambda＝c/f2，

calculating the aperture gain G _ peak of the interfered earth station antenna according to the diameter D of the interfered earth station antenna, the antenna efficiency eff and the wavelength lambda, wherein the unit is dBi, and the calculation formula is as follows:

calculating the half-power beam width theta-3 db of the interfered earth station antenna according to the diameter D and the wavelength lambda of the interfered earth station antenna, wherein the calculation formula is as follows:

calculating the off-axis gain I _ gain of the interfered earth station antenna with the unit of dB through the diameter D of the interfered earth station antenna, the wavelength lambda, the antenna aperture gain G _ peak, the half-power beam width theta _3dB and the top center angle theta _ t when the unit is dB

In time, the calculation formula of the off-axis gain I _ gain of the interfered earth station antenna is as follows:

when the temperature is higher than the set temperature

In time, the calculation formula of the off-axis gain I _ gain of the interfered earth station antenna is as follows:

I_gian＝29-25log(tehta_t)，

when theta _ t is larger than 36.4, the calculation formula of the disturbed earth station antenna off-axis gain I _ gain is as follows:

I_gian＝-10，

when the radiation pattern of the receiving antenna of the disturbed earth station is unknown, the calculation process of the receiving antenna gain of the disturbed earth station comprises the following steps of calculating the wavelength lambda of the electromagnetic wave transmitted by the disturbing satellite, wherein the unit is m, and the calculation formula is as follows:

lambda＝c/f2，

calculating a first side lobe gain G1 of an antenna radiation directivity diagram through the diameter D and the wavelength lambda of the interfered earth station antenna, wherein the unit is dBi, and the calculation formula is as follows:

calculating the main lobe width theta _ m of the interfered earth station antenna according to the diameter D of the interfered earth station antenna, the main lobe gain Gmax of the antenna, the wavelength lambda and the first side lobe gain G1, wherein the unit is degrees, and the calculation formula is as follows:

calculating the width theta _ r of a nearby lobe of the interfered earth station antenna through the diameter D of the interfered earth station antenna, wherein the unit is degrees, and the calculation formula is as follows:

calculating the off-axis gain I _ gain of the interfered earth station relative to the interference satellite in dBi according to the diameter D of the antenna of the interfered earth station, the wavelength lambda, the first boundary value theta _ m of the off-axis angle, the second boundary value theta _ r of the off-axis angle and the top center angle theta _ t when the unit is dBi

If 0 < theta _ t < theta _ m, the calculation formula is:

if theta _ m is less than or equal to theta _ t < theta _ r, the calculation formula is as follows:

I_gain＝G1，

if theta _ r is not more than theta _ t < 48, the calculation formula is as follows:

I_gain＝32-25log(theta_t)，

if 48 is equal to or less than theta _ t < 180, the calculation formula is as follows:

I_gian＝-10，

when the temperature is higher than the set temperature

When the utility model is used, the water is discharged,

if 0 < theta _ t < theta _ m, the formula is:

for example as body

The calculation formula is as follows:

I_gain＝G1，

if it is not

The calculation formula is as follows:

if 48 is equal to or less than theta _ t < 180, the calculation formula is as follows:

calculating interference physical quantity, wherein the interference physical quantity comprises a carrier-to-noise ratio CtON of a signal transmitted to the interfered earth station by an interfered satellite, interference power I of an interference signal of the interfered satellite to the interfered earth station, a carrier-to-interference ratio CtI, a carrier-to-interference plus noise ratio CtON _ I, an interference-to-noise ratio ItoN and an equivalent noise temperature increment percentage,

calculating the system noise N of the disturbed earth station in dB according to the calculation formula:

N＝10log(noise)-228.6+10logB，

calculating the carrier power C of a signal transmitted by a disturbed satellite to a disturbed earth station by the disturbed satellite transmitting power P1, the disturbed satellite beam Gain Gain1, the receiving antenna Gain upsilon _ Gain and the free space transmission loss v _ los8, wherein the unit is dB, and the calculation formula is as follows:

C＝P1+Gain1+υ_gain-v_loss，

calculating the interference power I of an interference signal of the interference satellite to the interfered earth station by the interference satellite through the transmission power P2 of the interference satellite, the beam Gain2 of the interference satellite, the Gain I _ Gain of a receiving antenna and the spatial transmission loss I _ loss, wherein the unit is dB, and the calculation formula is as follows:

I＝P2+Gain2+I_gain-I_loss，

calculating the carrier-to-noise ratio CtoN of a signal transmitted to the interfered earth station by the interfered satellite in dB, wherein the calculation formula is as follows:

CtoN＝C-N，

calculating the carrier-to-interference ratio CtoI with the unit of dB, wherein the calculation formula is as follows:

CtoI＝C-I，

calculating the carrier to interference plus noise ratio CtoN _ I with the unit of dB, wherein the calculation formula is as follows:

CtoN_I＝C-10log(10^N/10 +10^I/10 )，

the interference to noise ratio ItoN is calculated in dB, and is calculated as:

ItoN＝I-N，

calculating the equivalent noise temperature increment percentage DTtot of the satellite link by using the interference-to-noise ratio ItoN, wherein the unit is dB, and the calculation formula is as follows:

calculating interference physical quantity of all communication links corresponding to a plurality of earth stations and different communication links corresponding to different earth stations under a satellite transmitting beam; and for the transmitting beam of the interference satellite and the transmitting beam of the interfered satellite, selecting the worst value of each interference physical quantity from the interference physical quantities of all the communication links obtained by calculation, taking the worst value as a downlink interference calculation result between the two beams, and storing the worst value in a target table.

And displaying the interference calculation result. For the interference physical quantities Cton, ctoI and CtoN _ I, comparing an interference calculation result with a threshold, and displaying the target table as green when the interference calculation result is not lower than the threshold; and when the interference calculation result is lower than the threshold, displaying the target table as red to indicate that the interference is harmful. For interference physical quantities ItoN and DTtot, comparing an interference calculation result with a threshold, and displaying a target table as green when the interference calculation result is not higher than the threshold; and when the interference calculation result is higher than the threshold, displaying the target table as red to indicate that the interference is harmful.

An example is given below. Firstly, determining two satellite networks needing to be calculated, selecting a receiving earth station in each satellite network and recording the geographical position of the receiving earth station; respectively obtaining beam gains Gain1=38.2 (dBi) and Gain2=38.2 (dBi) of the geographical positions of the two earth stations according to GIMS contour line interpolation; and performing specific calculation according to the selected physical quantity, as shown below;

the specific input parameters are as follows:

the longitude of the disturbed earth station is 130 (degrees), and the latitude thereof is 50 (degrees); the earth station antenna diameter is 0.6 (m), the antenna efficiency is 0.6, and the frequency is 12000 (MHz); the gain of the disturbed satellite beam at the position of the earth station is 38.2 (dBi);

the orbit position of the disturbed satellite is 100.45 (degrees), the power fed to the antenna is 10 (dBW), and the frequency is 12000 (MHz);

the orbit position of the interference satellite is 96.5 (degrees), the power fed to the antenna is 10 (dBW), and the frequency is 12000 (MHz);

the bandwidth is 30 (MHz); the system noise temperature is 102 (K);

the calculation results are as follows:

calculating the vertex angle of the disturbed earth station relative to the two satellites to be theta _ t =4.26 (degrees); free space propagation loss v _ loss =205.8 (dB) from the victim earth station to the victim satellite; the free space propagation loss I _ loss =205.9 (dB) of the interfering earth station to the victim satellite; disturbed earth station antenna reception gain v _ gain =35.3 (dBi); receiving antenna gain of interfered earth station to interference satellite I _ gain =20.8 (dBi); system noise N = -133.7 (dB);

calculating physical quantity according to the calculated parameters to obtain a carrier-to-interference ratio CtoI =14.6 (dB); interference to noise ratio ItoN = -3.2 (dB); DTtoT =0.229; a carrier-to-interference-plus-noise ratio CtoN _ I =9.5 (dB);

and comparing the protection threshold value of the physical quantity selected by the user with the calculated physical quantity value to judge whether the interference is harmful or not. If the selected physical quantity is the carrier to interference ratio CtoI, a conclusion that the interference is harmful can be drawn according to the protection threshold of 21 dB.

The method and the device can obtain the downlink interference analysis result, and effectively improve the accuracy and efficiency of interference analysis; the proposed GIMS-based contour interpolation method provides a convenient and accurate way for future automated interference analysis.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims (2)

1. A downlink interference calculation method based on a space resource database and contour line interpolation is used for calculating downlink interference during communication between two satellites, wherein the two satellites are divided into interference satellites and disturbed satellites, and the method is characterized by comprising the following specific steps:

s1, marking the position of an earth station; marking earth stations corresponding to two satellites on a map, and acquiring position information of each earth station; defining a two-dimensional array, wherein the two-dimensional array is used for storing the position information of each earth station;

s2, establishing a target table; the target table is used for storing the finally calculated interference physical quantity; the target table contains a list of beams and beam directions, wherein a beam is a beam emitted by a satellite and used for communicating with the earth station;

s3, obtaining a beam contour line of a transmitting beam of an interference satellite and a transmitting beam of a disturbed satellite from GIMS map data in graphic interference system software GIMS developed by the International telecommunication Union, and interpolating based on the beam contour lines to obtain a transmitting beam gain of the disturbed satellite to the disturbed earth station and a transmitting beam gain of the interference satellite to the disturbed earth station;

s4, calculating a transmitting beam gain value at the earth station; recording the position of the earth station as a mark point, calculating a grid point closest to the mark point, recording a transmission beam gain value of the grid point, and taking the transmission beam gain value of the grid point as a transmission beam gain value at the earth station;

s5, calculating an interference value of a downlink beam from the satellite to the earth station, wherein the calculation process comprises the following steps:

firstly, searching the beam names of downlink beams of a disturbed satellite and an interference satellite in a satellite transponder table grp of a satellite space resource database SRS, searching corresponding satellite transponder numbers according to the beam names, searching all earth stations and all carriers corresponding to the searched satellite transponder numbers according to the searched satellite transponder numbers, calculating a transmitting beam gain value at the earth station according to the step S4, and determining the transmitting beam gain value at the searched earth station;

identifying a transmitting earth station of an interfered satellite as an interfered earth station and identifying a transmitting earth station of an interfering satellite as an interfering earth station; longitude of a geographical position of a disturbed earth station is long _ es, latitude is lat _ es, the diameter of an antenna of the disturbed earth station is D, antenna efficiency is eff, main lobe Gain of an antenna of the earth station is Gmax, disturbed satellite beam Gain of the position of the disturbed earth station is Gain1, disturbed satellite beam Gain of the position of the disturbed earth station is Gain2, a orbit position of the disturbed satellite is long _ sat, transmitting power of a feed antenna of the disturbed satellite is P1, transmitting frequency of a feed antenna of the disturbed satellite is f1, an orbit position of the disturbed satellite is long _ sat2, transmitting power of a feed antenna of the disturbed satellite is P2, transmitting frequency of a feed antenna of the disturbed satellite is f2, carrier bandwidth of the disturbed satellite is B, and system noise temperature of the disturbed earth station is noise;

calculating the space geometric relationship among the interference satellite, the disturbed satellite and the corresponding earth stations, wherein the space geometric relationship specifically comprises the following steps:

calculating a cosine value cos (ang 1) of an angle ang1 between the disturbed satellite and the disturbed earth station through the disturbed satellite orbit position long _ sat, the longitude and latitude (long _ es, lat _ es) of the disturbed earth station, and the calculation formula is as follows:

cos(ang1)＝cos(lat_es)×cos(long_sat-long_es)，

calculating the distance d1 between the disturbed earth station and the disturbed satellite, wherein the calculation formula is as follows:

calculating a cosine value cos (ang 2) of an angle ang2 between the disturbed satellite and the disturbed earth station through the longitude long _ sat2 of the disturbed satellite and the longitude and latitude (long _ es, lat _ es) of the disturbed earth station, wherein the calculation formula is as follows:

cos(ang2)＝cos(lat_es)×cos(long_sat2-long_es)，

calculating the distance d2 between the interference satellite and the interfered earth station, wherein the calculation formula is as follows:

the geocentric angle theta _ g of the two satellites is calculated through the orbit position long _ sat of the disturbed satellite and the orbit position long _ sat2 of the disturbed satellite, and the calculation formula is as follows:

theta_g＝|long_sat-long_sat2|，

and calculating the top center angle theta _ t of the disturbed satellite and the interference satellite relative to the disturbed earth station, wherein the calculation formula is as follows:

calculating the free space transmission loss upsilon _ loss of the electromagnetic wave from the disturbed satellite to the disturbed earth station, wherein the unit is dB, and the calculation formula is as follows:

υ_loss＝20(logf1+logd1)+32.45，

calculating the free space transmission loss I _ loss of the electromagnetic wave from the interference satellite to the interfered earth station, wherein the unit is dB, and the calculation formula is as follows:

I_loss＝20(logf2+logd2)+32.45，

calculating the gain upsilon _ gain of an on-axis receiving antenna of the disturbed earth station in unit dBi according to the diameter D of the antenna of the disturbed earth station, the frequency f1, the antenna efficiency eff and the light speed c, wherein the calculation formula is as follows:

wherein pi is a constant pi;

calculating the off-axis receiving antenna gain I _ gain of the disturbed earth station with the unit of dBi according to the diameter D, the frequency f1, the antenna efficiency eff, the optical speed c and the apical angle theta _ t of the disturbed earth station; when the receiving antenna radiation pattern of the disturbed earth station is determined, the receiving antenna gain calculation process of the disturbed earth station comprises,

calculating the wavelength lambda of the electromagnetic wave emitted by the interference satellite, wherein the unit is m, and the calculation formula is as follows:

lambda＝c/f2，

calculating the aperture gain G _ peak of the interfered earth station antenna according to the diameter D of the interfered earth station antenna, the antenna efficiency eff and the wavelength lambda, wherein the unit is dBi, and the calculation formula is as follows:

calculating the half-power beam width theta-3 db of the interfered earth station antenna according to the diameter D and the wavelength lambda of the interfered earth station antenna, wherein the calculation formula is as follows:

calculating the off-axis gain I _ gain of the interfered earth station antenna with the unit of dB through the diameter D of the interfered earth station antenna, the wavelength lambda, the antenna aperture gain G _ peak, the half-power beam width theta _3dB and the top center angle theta _ t when the unit is dB

In time, the calculation formula of the off-axis gain I _ gain of the antenna of the disturbed earth station is as follows:

when in use

In time, the calculation formula of the off-axis gain I _ gain of the interfered earth station antenna is as follows:

I_gian＝29-25log(tehta_t)，

when theta _ t is larger than 36.4, the calculation formula of the disturbed earth station antenna off-axis gain I _ gain is as follows:

I_gian＝-10，

when the radiation pattern of the receiving antenna of the disturbed earth station is unknown, the calculation process of the receiving antenna gain of the disturbed earth station comprises the following steps of calculating the wavelength lambda of electromagnetic waves emitted by an interference satellite, wherein the unit is m, and the calculation formula is as follows:

lambda＝c/f2，

calculating a first side lobe gain G1 of an antenna radiation directivity diagram through the diameter D and the wavelength lambda of the interfered earth station antenna, wherein the unit is dBi, and the calculation formula is as follows:

calculating the main lobe width theta _ m of the interfered earth station antenna according to the diameter D of the interfered earth station antenna, the main lobe gain Gmax of the antenna, the wavelength lambda and the first side lobe gain G1, wherein the unit is degrees, and the calculation formula is as follows:

calculating the width theta _ r of a nearby lobe of the interfered earth station antenna through the diameter D of the interfered earth station antenna, wherein the unit is degrees, and the calculation formula is as follows:

calculating the off-axis gain I _ gain of the interfered earth station relative to the interference satellite in dBi according to the diameter D of the antenna of the interfered earth station, the wavelength lambda, the first boundary value theta _ m of the off-axis angle, the second boundary value theta _ r of the off-axis angle and the top center angle theta _ t when the unit is dBi

If 0 < theta _ t < theta _ m, the calculation formula is:

if theta _ m is less than or equal to theta _ t < theta _ r, the calculation formula is as follows:

I_gain＝G1，

if theta _ r is not more than theta _ t < 48, the calculation formula is as follows:

I_gain＝32-25log(theta_t)，

if 48 is equal to or less than theta _ t < 180, the calculation formula is as follows:

I_gian＝-10，

when in use

When the utility model is used, the water is discharged,

if 0 < theta _ t < theta _ m, the formula is:

if it is not

The calculation formula is as follows:

I_gain＝G1，

if it is not

The calculation formula is as follows:

if 48 is equal to or less than theta _ t < 180, the calculation formula is as follows:

calculating interference physical quantity, wherein the interference physical quantity comprises a carrier-to-noise ratio CtON of a signal transmitted to the interfered earth station by an interfered satellite, interference power I of an interference signal of the interfered satellite to the interfered earth station, a carrier-to-interference ratio CtI, a carrier-to-interference plus noise ratio CtON _ I, an interference-to-noise ratio ItoN and an equivalent noise temperature increment percentage DTtot;

calculating the system noise N of the disturbed earth station in dB according to the calculation formula:

N＝10log(noise)-228.6+10logB，

calculating the carrier power C of a signal transmitted by an interfered satellite to an interfered earth station by using the transmitting power P1 of the interfered satellite, the beam Gain1 of the interfered satellite, the Gain upsilon _ Gain of a receiving antenna and the free space transmission loss upsilon _ loss, wherein the unit is dB, and the calculation formula is as follows:

C＝P1+Gain1+υ_gain-υ_loss，

calculating the interference power I of an interference signal of the interference satellite to the interfered earth station by the interference satellite through the transmission power P2 of the interference satellite, the beam Gain2 of the interference satellite, the Gain I _ Gain of a receiving antenna and the spatial transmission loss I _ loss, wherein the unit is dB, and the calculation formula is as follows:

I＝P2+Gain2+I_gain-I_loss，

calculating the carrier-to-noise ratio CtoN of a signal transmitted to the interfered earth station by the interfered satellite in dB, wherein the calculation formula is as follows:

CtoN＝C-N，

calculating the carrier-to-interference ratio CtoI with the unit of dB, wherein the calculation formula is as follows:

CtoI＝C-I，

calculating the carrier to interference plus noise ratio CtoN _ I with the unit of dB, wherein the calculation formula is as follows:

CtoN_I＝C-10log(10^N/10 +10^I/10 )，

the interference to noise ratio ItoN is calculated in dB, and is calculated as:

ItoN＝I-N，

calculating the equivalent noise temperature increment percentage DTtot of the satellite link by using the interference-to-noise ratio ItoN, wherein the unit is dB, and the calculation formula is as follows:

calculating interference physical quantity of all communication links corresponding to a plurality of earth stations and different communication links corresponding to different earth stations under a satellite transmitting beam; and for the transmitting beam of the interference satellite and the transmitting beam of the interfered satellite, selecting the worst value of each interference physical quantity from the interference physical quantities of all the communication links obtained by calculation, taking the worst value as a downlink interference calculation result between the two beams, storing the downlink interference calculation result into a target table, and displaying the interference calculation result.

2. The method of claim 1, wherein the step S3 comprises,

s31, carrying out uniform gridding division on the GIMS map data according to 0.125 degrees to obtain a plurality of grids and grid points;

s32, acquiring the longitude and latitude of each grid point on the GIMS map data, wherein the longitude and latitude is recorded (long, lat) in terms of the details;

s33, on the GIMS map data, selecting a beam contour line with the maximum corresponding beam gain value and a beam contour line with the minimum corresponding beam gain value from all beam contour lines, respectively and randomly selecting 3 sample points on the two beam contour lines, and storing the longitude and latitude and the gain value of each sample Point into a Point array;

s34, calculating the distances between all the sample points and the grid points through the longitude and latitude (long, lat) of the grid points obtained in the step S32 and the Point array obtained in the step S33, wherein the distance between the ith sample Point and a certain grid Point is represented as d _ i;

s35, calculating the gain of the emission beam at the corresponding grid Point by using the Point array obtained in the step S33 and the distance calculated in the step S34, wherein the calculation formula is as follows:

wherein, gain _ i is the transmission beam gain at the ith sample point, and n is the number of sample points.

Images