Apparatus for and method of forest-inventory management

• US 10,095,995 B2
• Filed: 11/25/2014
• Issued: 10/09/2018
• Est. Priority Date: 11/25/2013
• Status: Active Grant

• Current Assignee: First Resource Management Group Inc.
• Original Assignee: First Resource Management Group Inc.
• Inventors: Green, Philip E. J., St-Onge, Benoit
• Primary Examiner(s): Park, Edward
• Application Number:
  US15/037,894
• Publication Number:
  US 20160292626A1
• Time in Patent Office: 1,414 Days
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: G06Q 50/02 Agriculture; Fishing; Forestry; Mining
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/10032 Satellite or aerial image; Remote sensing
• CPC Class Codes: G06T 2207/30188 Vegetation; Agriculture
• CPC Class Codes: G06T 2207/30242 Counting objects in image
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

A forest-inventory management apparatus is for a forest image having forest information associated with a forest. The forest image is acquired from an in-flight vehicle. The forest-inventory management apparatus includes a server system. The server system includes a processor assembly and a non-transitory machine-readable storage medium configured to tangibly store a processor-executable programmed code. The processor-executable programmed code is configured to urge the processor assembly to execute the following operations: (A) read data representing the forest image having the forest information associated with the forest; (B) compute data representing a supply of forest inventory of hardwood and softwood trees expected to be available for harvesting based on the forest information associated with in the forest image; and (C) provide the data representing the supply of forest inventory expected to be available for harvesting from the forest associated with the forest image.

Claims

1. A system for creating an enhanced digital terrain model having enhanced resolution and accuracy for a target portion of the surface of the Earth, the target portion being subdivided into sub-portions of a first size, and being further subdivided into sub-portions of a second size, the second size being smaller than the first size, the system comprising:

a. an electronic interface for receiving, and a non-transitory memory for storing;

i. a base digital terrain model specifying an elevation for each first size sub-portion, the base digital terrain model being based on interferometric synthetic aperture radar data;

ii. a calibration digital terrain model corresponding to a reference portion of the target portion specifying a reference elevation for each second size sub-portion;

b. a computer processor configured to;

i. for the reference portion, calculate errors in the digital terrain model by comparing the elevations in the digital terrain model with the reference elevations in the calibration digital terrain model for the reference portion;

ii. obtain stereo imagery from an airborne or spaceborne imaging sensor of the target portion, the imagery being sufficient to permit the calculation of a surface elevation of each second size sub-portion;

iii. calculate a digital surface model by stereophotogrammetric analysis of the imagery, the digital surface model specifying a surface elevation for each second size sub-portion;

iv. calculate for each second size sub-portion, from the digital surface model, a terrain curvature value based on the digital surface model;

v. calculate a terrain curvature error correction function by comparing the errors in the digital terrain model with the terrain curvature values for the reference portion, the terrain curvature error correction function estimating the error in the digital terrain model elevations as a function of terrain curvature value;

vi. calculate, for each second size sub-portion, a corrected elevation by applying the terrain curvature error correction function to the elevation of the corresponding first size sub-portion in the digital terrain model based on the terrain curvature value of the second size sub-portion to produce the corrected elevation for the second size sub-portion in the enhanced digital terrain model; and

vii. produce a digital image of the target portion, the digital image comprising pixels, each pixel having a pixel size of at most the second size, each pixel corresponding to one second size sub-portion of the target portion, each pixel having a value calculated based on the corrected elevation specified in the enhanced digital terrain model for the second size sub-portion corresponding to the pixel, wherein the value is calculated in a manner to distinguish sub-portions of the target area at differing elevations from each other.

2. The system of claim 1, wherein the computer processor is further configured to calculate and apply a land-use error correction function based on land-use, and to apply the land-use error correction function to the elevations in the base digital terrain model prior to calculating the corrected elevations.

3. The system of claim 1, wherein the terrain curvature error correction function is calculated by regressing the errors in the digital terrain model against the terrain curvature values for the reference portion.

4. The system of claim 1, wherein the digital surface model is calculated by first calculating a high-resolution digital surface model specifying elevations for sub-portions having a size smaller than the second size, and then smoothing the high-resolution digital surface model using a filter.

5. The system of claim 1, wherein the computer processor is further configured to calculate a canopy height model for the target portion of the surface of the Earth, the canopy height model specifying a height for each of a plurality of sub-portions of the target portion, the height being calculated based on the difference between elevations for corresponding sub-portions specified in the digital surface model and the enhanced digital terrain model.

6. The system of claim 1, wherein the calibration digital terrain model is produced via LIDAR scanning of the reference portion.

7. The system of claim 1, wherein the reference portion is selected to comprise bare ground, and the calibration digital terrain model is produced by photogrammetric analysis of imagery of the reference portion.

8. A method of creating an enhanced digital terrain model having enhanced resolution and accuracy for a target portion of the surface of the Earth, the target portion being subdivided into sub-portions of a first size, and being further subdivided into sub-portions of a second size, the second size being smaller than the first size, the method comprising the steps of:

a. providing a base digital terrain model specifying an elevation for each first size sub-portion, the base digital terrain model being based on interferometric synthetic aperture radar data;

b. providing a calibration digital terrain model corresponding to a reference portion of the target portion specifying a reference elevation for each second size sub-portion;

c. for the reference portion, calculating errors in the digital terrain model by comparing the elevations in the digital terrain model with the reference elevations in the calibration digital terrain model for the reference portion;

d. obtaining stereo imagery from an airborne or spaceborne imaging sensor of the target portion, the imagery being sufficient to permit the calculation of a surface elevation of each second size sub-portion;

e. calculating, by a computer processor, a digital surface model by stereophotogrammetric analysis of the imagery, the digital surface model specifying a surface elevation for each second size sub-portion;

f. calculating for each second size sub-portion, from the digital surface model, a terrain curvature value based on the digital surface model;

g. calculating a terrain curvature error correction function by comparing the errors in the digital terrain model with the terrain curvature values for the reference portion, the terrain curvature error correction function estimating the error in the digital terrain model elevations as a function of terrain curvature value; and

h. calculating, for each second size sub-portion, a corrected elevation by applying the terrain curvature error correction function to the elevation of the corresponding first size sub-portion in the digital terrain model based on the terrain curvature value of the second size sub-portion to produce the corrected elevation for the second size sub-portion in the enhanced digital terrain model.

9. The method of claim 8, further including a step of calculating and applying a land-use error correction function based on land-use, and applying the land-use error correction function to the elevations in the base digital terrain model prior to calculating the corrected elevations.

10. The method of claim 8, wherein the step of obtaining imagery comprises flying an airborne vehicle containing the imaging sensor over or sufficiently close to the target area.

11. The method of claim 8, wherein the terrain curvature error correction function is calculated by regressing the errors in the digital terrain model against the terrain curvature values for the reference portion.

12. The method of claim 8, wherein the digital surface model is calculated by first calculating a high-resolution digital surface model specifying elevations for sub-portions having a size smaller than the second size, and then smoothing the high-resolution digital surface model using a filter.

13. The method of claim 12, wherein the filter is a moving average filter.

14. The method of claim 8, further comprising the step of calculating a canopy height model for the target portion of the surface of the Earth, the canopy height model specifying a height for each of a plurality of sub-portions of the target portion, the height being calculated based on the difference between elevations for corresponding sub-portions specified in the digital surface model and the enhanced digital terrain model.

15. The method of claim 14 further comprising the step of producing a digital image of the target portion, wherein the digital image comprises pixels, each pixel corresponding to a particular sub-portion of the target portion, each pixel having a value calculated based on a height specified in the canopy height model for a sub-portion corresponding to the pixel.

16. The method of claim 15, wherein the pixel values are calculated in a manner to distinguish sub-portions of the target area having differing canopy heights.

17. The method of claim 8, wherein the calibration digital terrain model is produced via LIDAR scanning of the reference portion.

18. The method of claim 8, wherein the reference portion is selected to comprise bare ground, and the calibration digital terrain model is produced by photogrammetric analysis of imagery of the reference portion.

19. The method of claim 8 further comprising the step of producing a digital image of the target portion, the digital image comprising pixels, each pixel having a pixel size of at most the second size, each pixel corresponding to one second size sub-portion of the target portion, each pixel having a value calculated based on the corrected elevation specified in the enhanced digital terrain model for the second size sub-portion corresponding to the pixel, wherein the value is calculated in a manner to distinguish sub-portions of the target area at differing elevations from each other.

20. The method of claim 19, wherein the image pixel values are proportional to the corrected elevation specified in the enhanced digital terrain model for the second size sub-portion corresponding to the pixel.