Imaging Sonar
Omniscan 450 Compact All-in-One Imaging Sonar
Omniscan 450 Compact - one housing
The Omniscan 450 Compact puts the transducer, the electronics and a three-port Ethernet switch in one housing, for small ROVs where the sonar bay and the cable run decide what will fit.
Sonar, electronics and a three-port switch in one housing
Every figure on this page lives somewhere on the unit. Hover or tap a number to trace it to the hardware.
- 01Footprint124 × 121 × 56 mmA form factor most small ROVs already have a bay for.
- 02Tilt10° downwardBuilt into the housing, so a flat-mounted bay still puts the beam on the seabed ahead.
- 03Bottom plate12 T10 Torx screwsRemoved, with the PCB, to fit an M10 WetLink penetrator in a spare port.
- 04InsideThree-port Ethernet switchThe sonar, a camera and a second sonar can share one Ethernet line. 10–30 V, 10 W max pinging.
- 05Depth rating300 m934 g in air, 400 g in water.
Every Omniscan 450 Compact Configuration
The same all-in-one Compact sonar throughout. What changes is the connector and the cable set it ships with. Every Compact is rated to 300 m and sees 100 m, whichever edition you order.
Key specifications15 rows▾
| Frequency (nominal) | 450 kHz |
| Maximum range | 100 m |
| Beam width | 1.1° |
| Beam height | 50° |
| Vertical beam angle | 10° downward |
| Far field | 4 m |
| Range resolution | up to 1/1200th of range |
| Maximum ping rate | 20 Hz |
| Max operating depth | 300 m |
| Weight in air | 934 g |
| Weight in water | 400 g |
| Power | 10–30 V, 10 W max (pinging) |
| Data interface | 100BaseT Ethernet |
| Internal Ethernet switch | Yes |
| Electronics | Built in |
Maximum range is a working figure, not a ceiling. Cerulean quote the range at which they have comfortably identified targets rather than inflate the specification. SonarView will let you set the range out to 200 m.
Far field is the range beyond which the beam-width figure holds. Inside 4 m the effective beam is wider and the sidelobes are larger. This is a sonar for finding and approaching things at 5 m and beyond, not for close inspection.
Beam width is the nominal theoretical two-way 3 dB figure. Cerulean advise in their documentation not to take it too literally in the wide dimension of the fan beam, because there is useful acoustic energy beyond the −3 dB point.
Dimensions are 124 × 121 × 56 mm. Cerulean publish no dimensions on either the product page or the specification page; this figure comes from Blueye Robotics, who sell the Compact as a payload for their own ROVs.
Published by Cerulean - specification page
Applications▾
- Search and recovery - cover ground in turbid water, find the anomaly acoustically, then fly the ROV to it
- Quay, pile and structure inspection - locate and approach structure in water where a camera shows nothing
- Navigation and obstacle avoidance - situational awareness for the pilot in zero visibility
- Wreck and archaeology work - targets standing proud of the bottom cast acoustic shadows that reveal height and shape
- Aquaculture and net inspection - approach and orientation around large submerged structures
- Habitat and seabed documentation - repeatable acoustic coverage logged for later replay
Features▾
- Fits where the FS will not - 124 × 121 × 56 mm, in a form factor most small ROVs already have a bay for. 934 g in air, 400 g in water.
- Frees up a port instead of taking one - the internal three-port switch means the sonar, a camera and a second sonar can share one Ethernet line to the vehicle. On a small ROV with one spare port, that is often the difference between a sensor fitting and not fitting.
- Points where you are looking - 10° of downward tilt is built into the housing, so it can go into a flat-mounted bay and still put the beam on the seabed ahead rather than into open water.
- Tells you it is alive - an externally visible LED shows power state and diagnostics.
- Takes a sensor instead of a device - one of the three ports can host a pressure or temperature sensor rather than an Ethernet device.
What's in the box▾
Cerulean’s own packing list for this product.
What’s in the box
- Omniscan 450 Compact unit with 1 m Ethernet cable terminated in 4-pin JST GH (fits the Blue Robotics Ethernet switch), with separate power and ground
- 4-pin JST GH to RJ45 (female) adapter
- 4-pin JST GH to 4-pin JST GH adapter
- 4-pin JST GH extension cable, 200 mm
- Blank penetrators fitted in the two spare ports
Cerulean's product page and their documentation list this box differently; between them the picture is the four items above plus the blanks. The blanks are what you remove to use the internal switch. Optional: one to three bulkhead connectors, fitted in place of them.
Downloads▾
How it actually works
It is the only Omniscan with a switch inside it, and the only one with downward tilt built into the housing. Those two things are why it exists alongside the Omniscan 450 FS, which sees further but takes a port and a bracket to itself.
The Compact has no moving parts. It projects one fixed beam - 1.1° wide and 50° tall - and pings up to 20 times a second. The picture comes from you: as the ROV yaws, SonarView stitches thousands of individual returns into a single coherent image, placing each ping at its correct bearing.
That has three consequences worth knowing before you buy.
You scan by flying. Point the vehicle at the sector you care about and you have an image of it straight away, rather than waiting for a mechanical head to travel round to where you are looking. Pilots who are used to a scanning sonar tend to find this faster once it clicks.
A stationary ROV sees a slice, not a picture. If your work is mostly hovering in one place, a mechanical scanning sonar suits you better. We would rather say that here than sell you the wrong sensor.
Heading data is doing real work. Omniscan has its own IMU, so even with no vehicle position data at all, SonarView places each ping at the correct compass bearing. Feed it vehicle attitude and position over MAVLink and it places pings in correct absolute orientation and position, live, with no post-processing. Most sonar in this price class gives you a waterfall display and leaves the geometry to offline software.
How this compares with mechanical scanning and multibeamOmniscan 450 Compact, and what it produces
Photographs of the hardware - not renders.
Mounting and integration
Tilt. The Compact has 10° of downward angle built in, and Cerulean note that a further 10° is ideal though not strictly necessary. Their own application notes recommend 20–25° down for the best range relative to height off the bottom. Mount one flat in a sonar bay and it will work, but it will not reach as far as the specification suggests. If range matters to you, plan a wedge or an adjustable bracket into the build.
Keep-out. Ideally nothing on the ROV sits proud of the sonar face. Cerulean acknowledge that this is not always practical with the Compact and publish estimated minimum keep-out zones in the mounting documentation. Worth checking against your frame before you order a bracket. Source
Using the Ethernet switch is a workshop job, not a deck job
This is the one thing to plan for. Adding a device to the internal switch means removing 12 T10 Torx screws and the bottom plate, removing the PCB, unscrewing a blank penetrator with a 16 mm wrench, fitting an M10 WetLink penetrator with a greased O-ring, then cutting the JST connector off the supplied power lead and wiring the stripped ends into a terminal block. It is well documented and entirely doable - but do it on a bench before the mobilisation, not on a quayside. Full procedure
Tell us what you want to chain off it when you enquire and we will quote the penetrators and cabling with the unit.
Common questions
Answers Cerulean publish, each linked back to the page it came from.
What makes the Compact different from the Omniscan 450 FS?
Everything is in one enclosure - transducer, electronics and a built-in Ethernet switch - and 10° of downward tilt is built into the housing. The trade is reach: 100 m maximum range against the FS's 120 m, and a 1.1° beam against 0.8°. If space and ports are tight, take the Compact. If you have room and want the extra range, take the FS. Source
What does the built-in Ethernet switch actually buy me?
One tether Ethernet line feeding up to three devices - the sonar plus two more, a camera or a second sonar. On a small ROV with a single spare port that is frequently what makes a second sensor possible at all. Adding a device means opening the housing and fitting an M10 penetrator, so plan it before the dive rather than on deck. Source
Why does it point 10° down?
The 50° beam height is tall, and angling it 10° downward puts more of that beam on the seabed ahead of a small ROV instead of into open water. Cerulean's own application notes suggest 20–25° is optimal for range relative to altitude, so a 10° wedge on top of the built-in angle gets you there. Source
Does the 300 m depth rating mean it sees 300 m?
No. 300 m is the depth the housing survives. 100 m is how far the sonar sees. Every Compact has the same figures for both. Source
Do I need a DVL to use it?
Not to get an image. The sonar's own IMU is enough for SonarView to place every ping at the correct compass bearing, and MAVLink attitude data improves that further. A DVL adds translational scanning - building the image as you move across a scene, not only as you turn. Cerulean's Doppler Motion Tracking can supply translational data along the beam without a DVL, with published ArduPilot parameters. Full 2D tracking and position hold are described by Cerulean using a pair of Omniscan 450 FS units, so ask us before assuming two Compacts do the same. Source
Is there a Blue Robotics edition?
No, and none is needed - the standard unit is what goes on a BlueROV2 or a BlueBoat. The factory editions exist for the vehicles that need a different connector: Blueye, CHASING, and the QYSEA FIFISH W6. Source
Can it see in zero visibility?
Yes. Sound is unaffected by turbidity, so the image looks the same in silty harbour water as in clear water - Cerulean describe the Omniscan as giving situational awareness in the murkiest conditions. What changes is interpretation: you are reading returns and acoustic shadows rather than a photograph. Source
Request an Omniscan 450 Compact quote
Tell us the vehicle and the water depth and we will confirm the exact part number - and say so if a different model suits the job better.
Anything you have added to your quote list is carried into this form automatically.