How to locate and select satellites for VSAT networks
Selecting a satellite for a VSAT network involves more than choosing the spacecraft with the strongest advertised coverage. The decision connects orbital position, service footprint, antenna size, frequency band, modem compatibility, regulatory permissions, and the physical conditions at every installation site.
A satellite that looks suitable on a coverage map may be difficult to receive from a particular location. Low elevation, nearby buildings, heavy rain, a narrow beam, or insufficient link margin can turn a technically available service into an unreliable connection. Careful analysis before procurement reduces expensive changes during installation.
SatPointer helps operators examine these variables from a selected location. Its map-based calculations show the azimuth, elevation, and look angle toward a satellite, while its satellite database provides useful information about beams and estimated dish requirements. The same process can support fixed VSAT terminals, temporary field links, maritime systems, and satellite uplink planning.
Start with the network requirement
Begin by defining what the network must accomplish. A small business terminal for internet access may need a different satellite and antenna from a hub-and-spoke corporate network, a cellular backhaul link, or a broadcast contribution service. Record the expected throughput, availability target, traffic pattern, latency tolerance, and number of remote sites before comparing orbital slots.
Decide whether the service is receive-only, transmit-and-receive, or primarily an uplink application. Downlink reception may work with a relatively compact dish, while an outbound VSAT requires adequate transmit power, authorized frequencies, and an antenna system that meets the satellite operator’s pointing and emission standards.
The installation environment also matters. List every site country, region, and approximate coordinate, then identify whether the terminals will be fixed, transportable, or mounted on vehicles. A satellite that serves one location well may have an unsuitable beam or elevation angle at another, especially when a network crosses several latitudes.
Build a shortlist from coverage and orbital data
Geostationary satellites are commonly compared by orbital longitude, because each spacecraft appears in a fixed position in the sky from a given region. However, the orbital slot alone does not prove that a terminal can use the service. The relevant regional beam must cover the installation point, and the operator must offer capacity on an appropriate transponder or managed platform.
Examine beam maps carefully. A footprint can show broad regional coverage while the actual usable signal falls near its edge. Contour values, polarization plans, frequency bands, and stated antenna sizes provide a better basis for selection than the satellite name alone. For multi-site networks, check whether all locations fall inside the same beam and whether a single hub can support the intended topology.
Use a satellite direction calculator to compare candidate positions from each site. Enter the installation location and inspect azimuth, elevation, and skew or polarization angle. SatPointer can also help organize a visual shortlist, and a customizable SatPointer widget can place satellite direction analysis directly on an internal planning page or technical resource.
Compare candidates with practical criteria
Once several satellites appear viable, compare them using consistent criteria. A low-cost capacity offer may be less attractive if it requires a larger antenna, has limited support in the target country, or operates near the edge of a beam. Conversely, a premium spacecraft may offer stronger availability and simpler installation across the whole network.
| Selection factor | What to examine | Why it matters |
|---|---|---|
| Orbital position | Longitude relative to each site | Determines the satellite’s visible direction and installation geometry |
| Beam coverage | Regional footprint and contour level | Indicates whether the site has sufficient downlink and uplink margin |
| Frequency band | C, Ku, Ka, or another supported band | Affects antenna size, rain sensitivity, equipment, and licensing |
| Elevation angle | Height of the satellite above the horizon | Low angles increase blockage, atmospheric loss, and alignment difficulty |
| Polarization | Linear or circular orientation and skew | Incorrect polarization can cause weak reception and interference |
| Capacity model | Dedicated, shared, managed, or leased transponder service | Influences performance, contention, cost, and service guarantees |
| Regulatory status | Licensing and coordination requirements | Determines whether the terminal can legally transmit |
| Equipment fit | Modem, BUC, LNB, antenna, and feed compatibility | Prevents redesign after the satellite has been selected |
The best candidate is usually the one that balances coverage, performance, availability, and operational simplicity. Include the commercial terms in the same comparison as the technical data. A satellite with an excellent footprint may still be unsuitable if capacity is unavailable in the required region or if the provider cannot support the desired service level.
Check the site before ordering equipment
A clear line of sight is essential. From the proposed dish location, identify trees, roofs, towers, ridges, and other obstructions in the satellite’s azimuth and elevation window. A satellite only a few degrees above the horizon is especially vulnerable to blockage, and seasonal vegetation can become a problem even when the initial site survey looks clear.
Use a map calculation for the exact or near-exact installation coordinates, then verify it physically. Satellite direction data can guide the survey, while landmark alignment methods can help installers estimate the direction before mounting the reflector. Landmarks are useful for preparation, but they should not replace a meter-based final alignment.
Consider structural and environmental conditions as well. The pole or wall must support the antenna in high winds, the mount needs a stable vertical reference, and cable routes should avoid sharp bends and unnecessary length. In coastal or tropical areas, corrosion, moisture, and heavy rainfall may influence the preferred antenna type and maintenance schedule.
Verify link performance and equipment compatibility
A satellite choice must satisfy both the receive and transmit sides of the link. Check downlink EIRP, G/T, transponder bandwidth, symbol rates, modulation options, forward error correction, and polarization. For outbound traffic, review uplink power control, BUC size, permissible emissions, and the operator’s minimum antenna diameter.
Rain fade deserves particular attention in Ku-band and Ka-band systems. A link that works during clear weather may lose service during intense rainfall if the design has little margin. Ask the provider for availability estimates and design the terminal around the required percentage of annual uptime rather than the smallest antenna listed in a general coverage document.
During commissioning, verify that the modem locks to the correct carrier and that the antenna is peaked for maximum quality, not merely maximum raw signal. If performance is unexpectedly poor, follow a structured diagnostic process using this guide to resolve low signal strength. Check obstruction, polarization, connector condition, cable loss, LNB or BUC configuration, and interference before replacing major equipment.
Account for operations and compliance
VSAT networks depend on more than physical signal acquisition. Confirm that the satellite operator or service provider supports the required countries, customer premises equipment, monitoring tools, and escalation process. Ask how the provider handles outages, planned transponder changes, network congestion, and emergency capacity.
Regulatory compliance is essential for transmitting terminals. National authorities may require landing rights, earth-station licenses, type approval, coordination, or specific emission limits. The satellite operator may also require an installation certificate, cross-polarization test, or remote commissioning procedure before activating the service.
Plan for changes over the network’s life. Beam plans, transponder assignments, service providers, and equipment firmware can change. Keep a record of each site’s coordinates, pointing angles, antenna model, polarization setting, modem configuration, and measured receive level. This information speeds up repairs and helps a replacement terminal return to service consistently.
Use practical selection rules
A repeatable decision process helps prevent individual preferences from dominating the satellite choice. Score each candidate against the same technical, commercial, and operational criteria, then validate the leading option with the provider’s current coverage and link-budget data.
- Reject any candidate whose active beam does not clearly cover every required site.
- Prefer a higher elevation angle when coverage, capacity, and regulatory conditions are otherwise comparable.
- Match frequency band and antenna size to the required availability, rainfall climate, and installation budget.
- Confirm modem, feed, LNB, BUC, polarization, and service-plan compatibility before purchasing hardware.
- Obtain written confirmation of licensing, capacity, commissioning requirements, and support responsibilities.
A short field trial can reveal issues that maps and documents cannot. Test the proposed antenna size, mounting position, cable route, and service profile during representative weather where possible. Measure receive quality, throughput, latency, and stability over time instead of relying on a single successful speed test.
With the candidate satellite, site geometry, and link budget documented, proceed to procurement and installation with a clear acceptance checklist. Use SatPointer to calculate directions for each location, verify the physical line of sight, and share the resulting coordinates and pointing data with installers and network engineers. A disciplined selection process turns satellite choice from guesswork into a defensible engineering decision.