34 results about "Satellite altimetry" patented technology

The invention discloses a fusion method of satellite altimetry gravity data and ship survey gravity data. The basic steps are: determining the fitting radius with the ship survey gravity data point as the center; calculating the weight of the satellite altimetry gravity data points within the fitting radius range ; Calculate the interpolation result of the satellite altimetry gravity data point at the ship survey gravity data point; calculate the difference between the interpolation result and the ship survey gravity data; calculate the correction value of each satellite altimetry gravity data point according to the difference and weight; The fusion calculation obtains the gravity fusion data. The method provided by the invention has the advantages of being scientific and reasonable, easy to implement, and high in precision, and improves the accuracy of marine gravity data fusion products through fusion of satellite altimetry gravity data and ship survey gravity data.

The invention discloses a local gravity anomaly extraction method based on satellite height measurement gravity data, which comprises the following basic steps of: processing satellite altimetry gravity data by using a sobel operator to obtain each gravity anomaly region; extracting a minimum enclosing rectangle of each gravity anomaly region according to the boundary line of each gravity anomalyregion; performing coordinate system rotation on the minimum enclosing rectangle of each gravity anomaly region to obtain a transformation rectangle, and obtaining a gravity anomaly value in each transformation rectangle region by utilizing an improved curved surface fitting method; performing interpolation processing on the gravity abnormal value of each transformation rectangle by utilizing a network function to obtain a regional abnormal gravity value of each gravity abnormal region; and finally obtaining a local gravity abnormal value of each gravity abnormal region. The method is scientific and reasonable and has high operability and practicability, and the satellite height measurement gravity data are processed through the network function interpolation method to obtain local gravityanomaly information.

The invention discloses a method for determining sea surface topographic structure based on barodynamics, which comprises the following steps: S1, performing the gross error detection on sea surface height data to obtain a gross error-free height data; S2, calculating a reference gravity field in satellite altimetry gravity field inversion; S3, based on the reference gravity field, deleting long-wave components in the sea surface topography from the gross error-free height data; S4, utilizing the gross error-free height data to separate the intermediate wave components in the sea surface topography; and S5, in the calculation of a geoid height by utilizing the reference gravity field, adding parameters which are acquired in the step of separating the intermediate wave components in the sea surface topography, and comparing the added result with a sea surface height acquired according to a satellite altimetry data so as to determine various frequency components in the sea surface height. By using the method, the reliable sea surface height data is acquired, thereby acquiring the accurate measured sea surface topographic structure data.

The invention discloses a satellite radar altimetry waveform resetting method based on the waveform derivative, which comprises the following steps: deriving the first-order derivative and the second-order derivative of the echo waveform based on the theoretical echo model; using the maximum value of the slope of the leading edge of the waveform, That is, when the second-order derivative is equal to zero, the calculation formula of the midpoint of the leading edge is obtained; the unknown parameters in the calculation formula of the midpoint of the leading edge are solved by fitting, and the position of the midpoint of the leading edge is determined; the resetting distance correction value is determined according to the preset tracking gate ;Further, according to the correction value of the resetting distance and the correction value of the height measurement error, calculate the sea surface height after the resetting method. The invention can improve the quality of satellite altimetry data, the high precision of the rescheduled sea surface is better than that of the conventional rescheduled method, and the correlation between the rescheduled sea surface height and the geoid height is obviously improved.

The invention discloses a method for extracting the lake and reservoir water level based on screened satellite altimetry data. The method includes the steps that satellite altimetry data is selected and downloaded, and basic editing processing is conducted on the satellite altimetry data; the lake and reservoir water level is preliminarily calculated with the satellite altimetry data and a water level altimetry formula; quality evaluation and quality grading are conducted on the satellite altimetry data according to the preliminarily calculated water level; abnormal data is screened out basedon the quality evaluation result, a high-quality data set is retained, and the altimetry mean water level is calculated to serve as the current lake and reservoir water level; finally, water level data of different periods is reduced to the same reference point, filtering processing is conducted in the whole time series, and gross errors are removed to obtain a relatively consistent lake and reservoir water level time series. The method can effectively eliminate interference caused by satellite altimetry data noise and improve the availability of satellite altimetry data and the precision of lake and reservoir water level monitoring.

The present disclosure relates to the technical field of lake water storage variation monitoring, in particular to a method, system, electronic equipment and medium for estimating lake water storage variation. The method includes: collecting and analyzing multi-source remote sensing images to obtain the area of ​​the lake, and collecting and analyzing multi-source satellite altimetry data to obtain the lake water level, wherein the multi-source remote sensing images and the multi-source satellite altimetry data are time-synchronized data ;Based on the lake area and lake water level, construct the lake area-water level relationship curve corresponding to the lake; according to the lake area-water level relationship curve and the lake's annual area, estimate the lake's water storage change, wherein the lake's annual area is based on global surface water data In this way, the accuracy of estimating the change in water storage of lakes can be improved.

The invention provides a method and system for estimating sea ice thickness distribution based on least squares adjustment, which processes satellite altimetry data and extracts related parameters, including latitude and longitude, elevation, average sea surface height, orbit number, pulse peak value and pulse Accumulated standard deviation; sea ice freeboard height extraction, including interglacial channel identification based on satellite echo signal-related characteristic parameters, to obtain sea ice freeboard height; sea ice thickness estimation, based on conversion from sea ice freeboard to sea ice thickness relationship, establish a function model in the grid unit, establish an observation equation, and use the least squares adjustment to solve the corresponding sea ice thickness results; perform resampling and filling to obtain the final sea ice thickness distribution map. The present invention gets rid of the traditional method of using empirical values, avoids the uncertainty brought by conditions such as snow thickness and snow density under the special geographical location and climatic conditions of the sea ice area, thereby improving the estimation of sea ice thickness. measured reliability.

A method for determining the position of the intersection of altimetry satellite tracks based on the minimum distance method, comprising the following steps: ① import satellite altimetry data; ② use the minimum latitude point to separate ascending orbit data and descending orbit data, and adjust the longitude of the arc to ‑180° ‑360°; ③ preliminarily judge whether the intersection point exists; ④ use the minimum distance method to obtain the two points with the closest distance between the ascending orbit and the descending orbit, and take 5 data points before and after these two points to obtain two binary ⑤ The first and last two points of the two arrays are connected to obtain a straight line, and four data points near the intersection of the two-day straight line are obtained; ⑥ The latitude and longitude coordinates and elevation of the exact intersection point are obtained by linear interpolation. This method can accurately determine the position of the ground intersection of altimetry satellite orbits, ensure the stability of calculating the elevation change of the polar ice sheet, and is suitable for studying the exact position of the intersection of multi-generation satellites and high latitude regions.

The invention discloses a method for improving the accuracy of a satellite altimetry cross point. The method comprises the following steps of: calculating the distance and the data density between adjacent data points on each track; selecting a track with the smallest data density in all the tracks as a reference track and the other tracks as tracks to be averaged; selecting the frequency of interpolation polynomial for each track to be averaged; fitting the tracks to be averaged by the polynomials; calculating the longitude, the latitude and the sea level height of a point, closest to each reference point, on each fitted curve; calculating the longitude, the latitude and the sea level height of a data point on an averaged track; circularly judging whether a cross point is generated and calculating the longitude, the latitude and the sea level height of the cross point; and converting the judgment of the cross point between two tracks into judgment on whether a connecting line section between two adjacent height measurement data points in any track forms an intersection point with a connecting line section between two adjacent data points in the rest tracks, wherein the intersection point is taken as the cross point. Compared with conventional methods, the method has the characteristics of high accuracy, easiness in calculation, wide application range, high operation efficiency and the like.

The present invention provides a sea area gravity anomaly inversion method and system based on satellite altimetry data. The method includes: calculating the sea surface height gradient of the sub-satellite point according to the sea surface height data collected by the satellite altimeter at the sub-satellite point in the preset sea area, According to the position of the sub-satellite point, the model vertical deviation gradient of the sub-satellite point is calculated, and the sea surface height gradient of the sub-satellite point is subtracted from the model vertical line deviation gradient to obtain the remaining gradient of the sub-satellite point; The remaining gradient of the next point is converted into a vertical deviation grid to obtain the remaining vertical deviation of the grid; the residual gravity anomaly of the grid is calculated according to the remaining vertical deviation of the grid, and the model gravity anomaly of the grid is calculated based on the gravity field model. Add the model gravity anomaly of the grid to the remaining gravity anomaly to obtain the gravity anomaly of the sea area of ​​the grid. The present invention realizes obtaining accurate sea area gravity anomalies through rigorous theoretical derivation.