Circular No. 71/2015/TT-BTNMT on remote sensing image acquisition techniques

CIRCULAR

TECHNICAL REGULATIONS FOR REMOTE SENSING IMAGE ACQUISITION

Pursuant to Decree No. 21/2013/NĐ-CP dated March 4, 2013, promulgated by the Government, stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment;

Pursuant to Decision No. 30/2014/QĐ-TTg dated April 26, 2014 of the Prime Minister on Management, Operation, and Exploitation of the First Earth Observation Satellite of Vietnam VNREDSat-1;

Pursuant to Decision No. 81/2010/QĐ-TTg dated December 13, 2010 of the Prime Minister on the Collection, Processing, Exploitation, and Utilization of National Remote Sensing Data; and Decision No. 76/2014/QĐ-TTg dated December 24, 2014 of the Prime Minister amending and supplementing certain provisions of Decision No. 81/2010/QĐ-TTg dated December 13, 2010 of the Prime Minister on the Collection, Storage, Processing, Exploitation, and Utilization of National Remote Sensing Data;

Considering the proposal of the Director of the National Remote Sensing Center, the Head of the Science and Technology Department, and the Head of the Legal Affairs Department,

The Minister of Natural Resources and Environment promulgates this Circular on technical regulations for remote sensing image acquisition.

PART I
GENERAL PROVISIONS

Article 1. Scope of Regulation

This Circular stipulates the contents and technical aspects of remote sensing image acquisition orders.

Article 2. Applicability

This Circular applies to agencies, organizations, and individuals involved in remote sensing image acquisition activities.

Article 3. Explanation of Terms

In this Circular, the following terms are understood as follows:

1. Remote sensing image acquisition order is the process of determining the requirements for image acquisition, preparing an order, and monitoring the implementation of the remote sensing image acquisition order.

2. The party placing the remote sensing image acquisition order (hereinafter referred to as the Ordering Party) is an agency or organization with the function of placing remote sensing image acquisition orders and authorized by competent authorities.

3. Customer are agencies, organizations, or individuals with a need for remote sensing image acquisition orders.

4. Remote sensing image acquisition order is an agreement between the customer and the ordering party regarding the placement of remote sensing data image acquisition.

5. Quicklook Image (from English "Quicklook") is a small-sized image derived from the actual image.

6. Minimum size for remote sensing image acquisition is the smallest area and side length allowed for the region to be placed for remote sensing image acquisition on the ground, and is specified separately for each type of remote sensing image.

Chapter II
TECHNICAL REGULATIONS FOR REMOTE SENSING IMAGE ACQUISITION

Article 4. Determination of Remote Sensing Data Requirements

1. Based on the customer's remote sensing data requirements, the ordering party must standardize the information content serving remote sensing image acquisition, including:

a) The location and scope of the area to be imaged based on one of the following cases:

- A polygon with the coordinates of its vertices. The sides of the polygon must not intersect, with a minimum of 3 and a maximum of 99 vertices;

- A rectangle with the coordinates of the top-left corner and bottom-right corner;

- A circle with the coordinates of the center and radius (accurate to seconds or kilometers). Coordinates can be geographic coordinates (accurate to seconds) or map coordinates (accurate to kilometers);

- Place names, administrative boundaries;

- Along linear objects, coastlines (rivers, seas);

On the basis of the above information, the ordering party must create a diagram to accurately determine the location and scope of the area to be imaged.

b) Time and frequency of imaging

- Time determined by day, month, year, or season;

- Frequency of single or repeated imaging.

c) Technical parameters of the image

- Name of the image data type (sensor or satellite);

- Imaging mode;

- Angle of image tilt;

- Overlap between images;

- Spectral band;

- Ground resolution;

- Number of bits to represent the grayscale value of a pixel.

d) Purpose of using remote sensing images.

e) Cloud cover percentage according to the levels prescribed in Circular No. 10/2015/TT-BTNMT dated March 25, 2015 of the Ministry of Natural Resources and Environment on technical regulations for producing high-resolution and ultra-high-resolution optical remote sensing images for provision to users.

f) Coordinate system: National Coordinate System VN-2000 or other coordinate systems as required by the customer.

2. For urgent requests, only the area to be imaged needs to be determined based on information about coordinates or place names, the scope of the area, and the time required for remote sensing image acquisition.

Article 5. Construction of Orders for Remote Sensing Photography

The party placing the photography order must carry out the following steps:

1. Categorize and prioritize photography requests based on their level of urgency.

2. Analyze and assess the compatibility between the customer's application needs and the types of remote sensing images and corresponding parameters required. Based on the analysis results, work with the customer to select and place orders for remote sensing images with the most suitable parameters.

3. Calculate and determine the size of the areas to be photographed. If the size of the areas to be photographed is smaller than the minimum photographing size, coordinate with the customer to adjust accordingly, ensuring that all areas meet the required size.

4. Preliminarily evaluate the feasibility of the customer's photography request and classify it into three levels: high, medium, and low.

5. Estimate the area, number of images, or image strips needed to be photographed, and the time required to complete the entire or partial photography request.

6. Adjust the photography order if the customer wishes to change the feasibility, area, number of images, or estimated construction time.

Article 6. Placing Orders for Remote Sensing Photography

1. The party placing the photography order compiles the photography orders, including new photography orders and ongoing photography orders. If there are overlapping areas in the photography requests, priority will be given to the request with higher requirements for execution time or technical parameters.

2. The party placing the photography order sends the order to the satellite operation agency.

Article 7. Confirmation and Clarification of Order Content

Based on the order constructed under Article 5 of this Circular, the party placing the photography order collaborates with the satellite operation agency to confirm and clarify the content of the order, including the following steps:

1. Conduct a detailed feasibility analysis of the order according to the levels specified in Clause 4 of Article 5 of this Circular, based on balancing the following factors:

a) The timing, location, and technical parameters of the photography request;

b) Other orders and photography requests currently being and to be carried out by the satellite operation agency;

c) The imaging capability and current resources of the satellite;

d) Statistical data on weather conditions in the area requiring remote sensing photography in previous years;

đ) Weather forecast information at the photography location provided by the National Hydro-Meteorological Center.

2. Accurately calculate the area, number of images, or image strips needed to be photographed and the time and timing for implementing each component of the photography request.

3. Adjust the photography order if the customer wants to change the feasibility, area, number of images, or estimated construction time.

4. The party placing the photography order officially confirms the content of the order and the construction time with the satellite operation agency and the customer.

Article 8. Monitoring the Execution of Remote Sensing Photography Orders

During the implementation of the order, the party placing the photography order must regularly perform the following tasks:

1. Inspect and evaluate the quality of the photographs through quick-view images. If the quality of the photographs does not meet the requirements, notify the satellite operation agency to retake the photographs. The content of the items to be inspected is carried out in accordance with Article 9 of this Circular.

2. Monitor weather information at the construction sites. If the weather forecast at the photography locations is favorable (clear skies, few clouds), the party placing the photography order will proactively request the satellite operation agency to expedite the remote sensing photography schedule. In cases where the weather forecast is unfavorable, the party placing the photography order will request the satellite operation agency to temporarily halt the remote sensing photography.

Article 9. Quality inspection of remote sensing images

1. The party ordering remote sensing images shall regularly inspect and evaluate the quality of the captured remote sensing images throughout the execution of the order in accordance with technical standards, specifications, and current State regulations. The contents to be inspected include:

a) The position of the captured remote sensing image must coincide with the area specified for photography in the order;

b) The cloud cover of the captured remote sensing image must be lower than or equal to the required cloud cover;

c) The captured remote sensing image must ensure image quality during signal reception and processing. The signal must not have errors or interruptions, the image must have uniform contrast, must not be overexposed, must not be too dark, and must not contain black spots or streaks due to system errors.

2. In cases where the captured remote sensing images do not meet requirements, the party ordering the remote sensing images will request the satellite operation agency to retake the photographs.

Chapter III
IMPLEMENTING PROVISIONS

Article 10. Effective Date

This Circular takes effect from February 15, 2016.

Article 11. Implementation Organization

1. Ministries, ministerial-level agencies, agencies under the Government; People's Committees of provinces and centrally governed cities, and related organizations and individuals are responsible for implementing this Circular.

2. The National Remote Sensing Center, Ministry of Natural Resources and Environment is responsible for guiding and inspecting the implementation of this Circular.

3. Provincial Departments of Natural Resources and Environment are responsible for assisting the People's Committees of provinces and centrally governed cities in implementing this Circular at the local level.

4. During implementation, if there are any difficulties, agencies, organizations, and individuals are requested to promptly report them to the Ministry of Natural Resources and Environment for consideration and decision.