Creating digital orthophotos solves the following tasks:
- Creating a high-precision cadastral framework.
- The performance of land surveying and cadastral works.
- Updating topographic information.
- Solving other production-related tasks at oil and gas fields under development.
Creation of digital orthophotos of 1:5000 – 1:500 scale is performed in accordance with the instructions for the production of surveying works RD 07-603-03 and the requirements of other regulatory and technical documents in order to create an updated cadastral basis.
Figure 1. Sample of 1:5000 orthophotoplane for oil and gas sector objects
Modern earth remote sensing spacecraft have a spatial resolution of up to 15 cm per pixel and high visibility to quickly obtain information over large areas. And drones allow you to quickly get images with a spatial resolution of up to 2-5 cm per pixel.
In accordance with this, space and aerial photographs allow you to:
- Create orthophotos at a scale up to 1: 2000 (using satellite images).
- Create orthophotos at a scale of up to 1: 500 (using UAVs).
- Create a high-precision DEM for orthocorrection.
- Identify previously unrecorded items.
- Quickly respond to the state of terrain objects.
- Significantly reduce the time of work due to visibility and speed of data acquisition.
Satellite image from the WorldView-3 satellite with a spatial resolution of 0.4 m before orthorectification (left), ready-made orthophotoplane (right).
Creation of digital orthophotos is carried out in the following stages:
1. The selection of raw materials;
Depending on the required accuracy and the purpose of using the product, different data can be selected. The selection of materials is carried out strictly according to the customer's requirements. For example, when creating 1:5000 scale orthophotos, a planned accuracy of at least 5 m is required, and materials with a resolution of at least 0.5 m are required to meet this accuracy. Chinese and Korean SATELLITE images are suitable for this purpose
2. Preliminary analysis of source materials;
After receiving remote sensing materials, they need to be checked for high-quality mutual binding of channels, the absence of "broken" pixels and missed shooting bands. As well as the completeness of materials on the territory of interest.
3. Working technical design of processing processes;
The working technical design should specify and technically justify the recommended processing methods. At the same time, it is necessary to take into account the nature of the terrain and buildings, the quality of images, the density and location of points of geodetic networks and survey justification, and the equipment with photogrammetric devices and software.
When working on technical design, a scheme of work on photogrammetric thickening of the reference network and a scheme of work on drawing up original maps (plans) are drawn up. The choice of photogrammetric image processing is justified.
Depending on the volume and quality of planned high-altitude training, the technological scheme of office processes may include:
Photogrammetric thickening of the survey justification (with sparse field preparation of images) and subsequent collection of digital information about the area from single images or stereo pairs oriented according to photogrammetric thickening data.
Processing of single images or stereo pairs that are oriented directly to the points of field training (when the images are solidly linked) or to contour points identified on existing images from previous years or on maps (plans) of a larger scale.
Working technical design of photogrammetric condensation includes the selection and designation of points of the photogrammetric network, as well as drawing up a network diagram.
4. Primary image processing;
Primary image processing includes elimination of image defects (missing pixels, stripes), radiometric, geometric, and atmospheric correction of images;
5. Photogrammetric processing of source data;
Photogrammetric processing includes:
- the establishment of a swivel mounting;
- performing internal orientation of images;
- the implementation of the relative orientation of the images:
- the implementation of external orientation;
- creating a DEM (assuming the use of stereo photography);
- data orthotransformation;
- the creation of a seamless mosaic;
- alignment of the mosaic color characteristics.
6. Export of received materials;
The final product can be exported to different formats depending on the customer's software used. Also, depending on the Customer's requirements, the finished orthophotoplane can be cut according to the layout, the weight of the images, the mileage, and so on.
7. Control of work completion;
Control over the creation of digital orthophotos is performed using standards and reference points. It evaluates relative and absolute binding errors, correct cross-linking of images by object, and so on.
In conclusion, the final analytical report is issued, which reflects statistical, analytical and technical information about the work performed,and the progress of the work.
Work on creating digital orthophotos is necessary for oil companies, mining and service organizations to provide accurate, up-to-date information about the area to perform land management, cadastral and other production tasks.
The mechanism of realization of services:
GEO INNOTER LLC: receiving and processing satellite images, their primary and photogrammetric processing, monitoring the performance of work and drawing up a report.
Through local partners: Field work and aerial photography.
Advantages of GEO INNOTER LLC in creating digital orthophotos:
- Extensive experience in creating digital orthophotos.
- Highly qualified employees working with remote sensing materials.
- The latest software for photogrammetric processing of satellite images.
- GEO INNOTER LLC is included in the list of expert companies of the Ministry of Justice of the Russian Federation for the analysis of remote sensing materials and conducting expert examinations.
- Network of experienced local partners