site survey for vsat communications

Slide Number 1Rev -, July 2001

Technical Introduction to Geostationary Satellite Communication Systems Original Prepared by Telesat Canada

Site SelectionSection 3


Vol 4: Earth Stations




4.3: Site Selection

• Any site selection process should be flexible in order to accommodate specific needs of the client, diverse aspects of the individual project, and characteristics of the geographic area.

• The objective of the process is to examine and compare possible locations and to establish a best-site recommendation, with alternatives if possible.

• The site-selection process should also establish a record of all sites that have been considered, and how the conclusions have been reached.

• Select and adapt as required the following suggestions for a site selection team and process.

Preamble




4.3: Site Selection

• For the purpose of clarifying the Site Selection function, a rather arbitrary distinction will be drawn between large and small sites.

Two Types of Sites

Large SmallExamples Teleport VSAT SiteFeatures Multiple User

Antenna “Farm” Land Required High Power

Transmission

Single User One Antenna No Land Required Low Power

Transmission orReceive-Only



Sec 3: Site Selection

4.3.1: Large Sites


Telesat’s Network Operating Center Earth StationPhoto Courtesy of Telesat Canada

Figure 4.3.1. Telesat’s Network Operating Center Earth Station



Every proposed satellite ground station will have its own unique site issues to consider, so it is essential to have the right skills available to make the right decisions.

The following personnel may be required on the Site Selection Team for large sites:

Vol 4: Earth Stations, Sec 3: Site Selection

Part 1: Large Sites

4.3.1.1: The Site Selection Team (Large Sites)

The Team

1. Business Case Developer1. Business Case Developer

2. Architect, Facilities Engineer, 2. Architect, Facilities Engineer, ContractorContractor

4. Real Estate Agent4. Real Estate Agent

3. Communications & RF 3. Communications & RF EngineerEngineer

8. Lawyer8. Lawyer

7. Archeologist / Other 7. Archeologist / Other

6. Environmental Engineer6. Environmental Engineer

5. Geotechnical Engineer5. Geotechnical Engineer



A Business Case is a multifaceted analysis designed to assist in the planning and implementation of a financial venture.

Establishing the business case for an earth station project is an important step prior to actively beginning the site selection and engineering process.

It is essential to clearly establish the main criteria for choosing the site. This includes defining the:


Part 1: Large Sites

4.3.1.1: The Site Selection Team

4.3.1.1.1: The Business Case Developer

• Location with respect to the intended market

• Size and growth potential to be included in the facility

• Staffing requirements

• Acceptable price range (if applicable)



Development of large sites may involve:• An entire complex for a significant number of staff

• A technical office for only a few people

• An unstaffed facility which is little more than an equipment shelter

Existing structures may be rendered suitable with refurbishment, or an existing Teleport may need only minimal improvements to accommodate a new service.


Part 1: Large Sites


4.3.1.1.2: The Architect, Facilities Engineer, Contractor



Provides guidance to the site selection process so that the chosen site and layout will:

• Suit the communication purpose for which it is intended and not interfere with other communications facilities

• Be sufficiently free of RF interference

• Be able to obtain the required RF licenses

• Not endanger the public (RF radiation)


Part 1: Large Sites


4.3.1.1.3: Communications and RF Engineer



If land or buildings are to be purchased or leased, the services of a Real Estate Agent may help in locating candidate sites.


Part 1: Large Sites


4.3.1.1.4: A Real Estate Agent

Soil investigation to the extent required to confirm site suitability is recommended as part of the evaluation and site selection process.

4.3.1.1.5: The Geotechnical Engineer

Environmental site assessments are recommended to ensure that sites with unacceptable conditions are not selected and that the scope of any existing site problem be recognized to establish the risk of liability.

4.3.1.1.6: The Environmental Engineer




Part 1: Large Sites


An archeologist may be able to advise if a site is likely to have issues which could adversely affect the planned development.

4.3.1.1.7: An Archeologist or Other Specialist

A Lawyer is required to ensure proper title transfer on all land or building purchases or for lease arrangements.

4.3.1.1.8: Legal Counsel




Part 1: Large Sites


One of the involved specialists should be assigned as Team Leader or Project Manager to co-ordinate and oversee the entire effort.

It may be found cost-effective to contract some of the required services externally.

For projects requiring sites in a wide geographic area, local representation on the site selection team may be cost effective and help ensure that essential local information is considered.

Closing Comments



Site selection is a multi-step process to establish and rank the importance of all relevant criteria. The objective of the process is to identify the best location from among many competing options. There are three principle steps:

Step 1 - Site Screening

Step 2 - Preliminary Site Evaluations

Step 3 - Final Report with Recommendations


Part 1: Large Sites

4.3.1.2: The Process

Opening Comments



This is the initial evaluation to create a short list of sites for further consideration from a large number of properties offered.

This evaluation is normally done on the basis of available information only, rather than visits to the sites.

Real Estate agents typically have data sheets and photos with all the relevant particulars, and this may be enough to confirm or reject a proposed location on the basis of compliance with the main criteria.


Part 1: Large Sites


4.3.1.2.1: Site Screening




Part 1: Large Sites


4.3.1.2.2: Preliminary Site Evaluations

This includes:

• Site visit.

• Development of a concept sketch of how the site could be utilized.

• Inquiry about zoning and other local regulation that would affect development plans.

• Review of any available geotechnical and environmental information. If such information is insufficient, a new environmental investigation must be accomplished.

• Preparation of a Rough Order of Magnitude (ROM) cost estimate for site development if it is necessary to compare sites with differing development concepts.




Part 1: Large Sites


4.3.1.2.3: Final Report With Recommendations

This includes:

• Preparation of a final report with perhaps a first, second and third choice identified, with a comparison among them for cost or other issues.

• There is a need for alternatives in case negotiations for acquisition of the first-choice site are not successful.

• A concept sketch of site utilization confirming that size and configuration suits the intended purpose. This can also serve as a pictorial representation for cost estimates.

• Summary of other issues (such as RF, geotechnical, environmental or archeological) to the extent required to support recommendations.




4.3.2: Small Sites


1.0m VSATPhoto Courtesy of Telesat Canada

Figure 4.3.2. Rooftop NPM VSAT



Opening CommentsThe Site Survey is typically done by someone familiar with the equipment and service requirements.

There is also a structural engineering component involved in the design of foundations or the review of existing structural adequacy.

This can all be done by one person with the necessary qualifications, or the engineering design can be handled by someone other than the person doing the site survey.

The site selection team for a large network of small sites, then, differs from a large-site team by being geographically dispersed. Each team member is capable of performing the whole task.

By contrast, the large site team consists of professionals who each have their own specialty and perform only part of the task.


Part 2: Small Sites

4.3.2.1: The Site Selection Team (Small Sites)



Opening CommentsPrograms of this type may include a large number of sites using the same type of equipment, or equipment with a limited number of differences.

The customer often requests that the equipment is installed on their premises.

A prime objective for site selection and equipment installation is to efficiently and economically handle the requests for service.


Part 2: Small Sites

4.3.2.2: The Site Selection Process (Small Sites)



The ProcessConsider a process for site selection and development that will include the following:

4.3.2.2.1: Site SurveyA Site Survey identifies the requirements of the customer and provides details of the site and required engineering so that the installation can be done in a way which is satisfactory to the customer.

The Site Survey can be done with standard forms filled in by trained staff or on-call consultants while they are on site. This will be the record of customer requests, required work, and will provide consistent information about each site.

The persons doing the survey must be aware of the preferred and least cost approaches.


Part 2: Small Sites




The Process4.3.2.2.2: Cost EvaluationIt is necessary to evaluate the costs of providing the service. This evaluation should look for economies of engineering, organization and construction. It is recommended that pre-engineered and pre-fabricated foundation parts be considered to suit a range of applications and to reduce the overall site cost.

Non Penetrating Mount (NPM) foundations installed on flat roofs are generally the most cost-effective solution for antenna sizes up to 2.4 meters.

If a wall and ground mount is needed, these typically are steel pipes to suit the antenna interface. Brackets for mounting on walls or concrete can be site-specific and require design services.


Part 2: Small Sites




4.3.2.2.3: RF Radiation Study Information Most small antennas are low power and do not pose significant public risk. However, everyone associated with planning and installing the equipment must understand the requirements and safety issues so that clearances are provided.

While on-site radiation studies are seldom necessary for small sites, it is necessary to test every antenna configuration once, and retain the information on hand for further reference.

4.3.2.2.4: Pre-installation Visits It is a good idea to maintain a trained team of engineers and contractors who will visit sites in advance of equipment installation to determine requirements for installation.

This initial visit includes confirming satellite visibility, determining the foundation requirements, and providing construction work for foundations if needed.


Part 2: Small Sites




Information to Include in the Site Survey Report• The site address and necessary detail for access,

installation and operation of the site.

• List of planned equipment (antenna model and electronics).

• Satellite azimuth and elevation angles, magnetic declination.

• Design wind for antenna location.

• Foundation drawings (NPM and ballast details with evaluation of existing roof structure, or construction drawings to be used for other types of foundations).


4.3.3: The Site Survey Report




Information to Include in the Site Survey Report• Relevant building details (height to roof for NPM etc.).

• Equipment location identified and sketched.

• Confirmation of power source.

• Proposed cable routing between antenna and equipment.

• Identification of any specific landlord requirements.

• Confirmation of landlord agreement to the proposal. • Photos and sketches, as required, to show antenna location,

view to the satellite, equipment area, cable routing, access route to be used for antenna placement, front of building if it would be useful to help find the site, and so on.


4.3.3: The Site Survey Report




Is a Site Survey Needed?YES • For all 1.8m and larger antennas. If used with an NPM, these

antennas exert significant forces on a roof structure.

• For any size of antenna if the site requires engineering, construction work, building permits, or verification of roof capacity.

• If it is important to avoid a delay in start of service.


4.3.4: Is a Site Survey Needed?


Without a Site Survey, equipment installers may encounter problems that prevent installation. A return visit may be needed with other materials, or a site survey may still be needed for design and construction of a special foundation.



Is a Site Survey Needed?NO

• For 1.2m and smaller antennas, if a pre-engineered installation can be safely used and:

• Permits are not required for installation

• The customer doesn’t request a survey

• If the risk of incomplete installation on the first site visit is acceptable



4.3.4: Is a Site Survey Needed?

site survey for vsat communications

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