Two very different ways to read the wind at long range. We put them side by side on technology, features, calibration, use, compatibility and price.
At distance, wind is your biggest opponent. You can work out elevation fairly precisely, but a misjudged crosswind can put you well off target at distance. Two devices that hop.nl carries tackle that problem in completely different ways, the Kestrel 5700 Elite with Applied Ballistics and LiNK and the Calypso Ultrasonic Portable Mini AB. One is a complete weather meter with a built-in ballistic solver, the other a tiny ultrasonic wind sensor with no screen. Both work with Applied Ballistics, but in a different way and for a different type of shooter. In this comparison you will read exactly where the difference lies.
In short
If you want a standalone device that measures wind and climate and shows the full ballistic solution on its own screen without a phone, the Kestrel 5700 Elite is your pick. If you use the Applied Ballistics software and want a tiny, robust wind sensor that also measures wind direction and feeds live wind into that software at a lower price, the Calypso Mini AB is ideal. They can also complement each other, though that does take some thought about your workflow.
Two philosophies side by side
The Kestrel is a handheld weather meter that has been the standard in precision shooting for decades. It uses a small impeller to measure wind speed and its sensors to measure temperature, humidity and pressure. The Elite also carries the full Applied Ballistics solver, so the device works out your elevation and windage correction itself and shows it on the screen. You need nothing else.
The Calypso Mini AB takes the opposite route. It is a sensor, not a computer. In a housing of barely 43 mm sit four ultrasonic transducers that measure wind speed and wind direction, and it sends that data over Bluetooth to your phone or tablet. The Calypso itself has no screen and no ballistic software, it only delivers the wind, but it does that exceptionally well and in a size you always carry.
Kestrel 5700 Elite
A complete weather meter and ballistic solver in one, with its own screen and LiNK.
Calypso Mini AB
Ultrasonic wind and direction sensor with no moving parts, streams to the Applied Ballistics software.
The technology, impeller versus ultrasonic
The biggest technical difference is in how they measure the wind. The Kestrel uses a small, light impeller that the wind spins around. It is a proven, accurate method, but it is a moving part that could in theory be damaged if you drop the device. Fortunately the impeller on the Kestrel is easy to replace.
The Calypso has no moving parts at all. Its four ultrasonic transducers send sound waves to each other, and the time a wave takes changes with the wind. From those tiny time differences the device calculates both speed and direction. There is no mechanical impeller that first has to start turning and no bearings that can wear out mechanically. That said, the minimum specified wind speeds are close together, the Kestrel is specified from 0.6 m/s and can read down to about 0.4 m/s after the impeller has started, while the Calypso has a threshold of 0.5 m/s. The main constructional advantage of ultrasonic measurement is therefore not lower wind speeds, but the absence of moving parts. The Calypso measures at a sample rate of 1 Hz, a fresh reading every second.
What they measure, the capabilities
This is where the two diverge sharply, and it is the most important thing to grasp before you choose. The Kestrel 5700 Elite is a full weather meter. It measures wind speed, temperature, relative humidity and pressure, and from those it calculates the atmospheric values your ballistic solution needs, such as air density, density altitude, dew point, crosswind and head or tailwind. From its temperature, pressure and humidity sensors the Kestrel therefore determines the complete atmospheric state on the spot.
The Calypso measures wind only, speed and direction. No temperature, no pressure, no air density. That sounds like a limitation, but it is a deliberate choice, because the Calypso is meant to work together with software or a device that already has those other values. What the Calypso does as standard, is continuously measure both wind speed and wind direction without a moving wind vane. On the Kestrel you determine wind direction with the digital compass, and for continuous hands-free measurement the Kestrel can be placed on a Rotating Vane Mount.
Wind direction on the range
On the range that difference plays out as follows. The Calypso measures wind direction directly, from 0 to 359 degrees, because the ultrasonic sensors see the wind from every angle. For speed the orientation of the device does not matter, but for a correct wind direction relative to your shooting direction you do need to line up the reference marker. Put it on a tripod at your shooting position and line the triangle marker up with your range, and you continuously read where the wind is coming from, without doing anything. The Kestrel uses the digital compass to give crosswind and head or tailwind alongside wind speed, for which you point the meter into the wind by hand.
Applied Ballistics and compatibility
Both devices carry Applied Ballistics in the name, but in a different way. The Kestrel Elite runs the full Applied Ballistics solver by Bryan Litz, with the Applied Ballistics library holding G1 and G7 data for more than 500 bullets, plus Applied Ballistics Custom Drag Models and corrections for aerodynamic jump, spin drift, Coriolis and drop scale factoring. So the Kestrel produces the ballistic solution itself and needs no phone for it.
The Calypso Mini AB is directly compatible with the Applied Ballistics ecosystem. Over Bluetooth it feeds live wind data to the Applied Ballistics software AB Quantum, which then manages the connection with supported rangefinders. Which hardware is supported directly varies by device and firmware version. Importantly, the Calypso does not pair with the Kestrel 5700 by itself, it works with the wider AB software platform. The Calypso also has its own free Anemotracker app with a dedicated Ballistics mode alongside Marine, Golf and Meteo.
Compatibility | Kestrel 5700 Elite | Calypso Mini AB |
|---|---|---|
Own ballistic solver | Yes, fully on board | No, delivers wind only |
Needs a phone or tablet to use | No, works standalone, optionally links to your phone via LiNK | Yes, for display and calculation |
Streams live wind to AB Quantum by Applied Ballistics | n/a (solves itself) | Yes, over Bluetooth |
Pairs directly with the Kestrel 5700 | n/a | No, not documented |
Pairs with the TANGO FIRE4000 Elite | Yes | Yes, sends real-time wind data |
Works with rangefinders (LRF) | Yes, via LiNK with supported laser rangefinders | Through AB Quantum, which manages pairing |
Calibration and accuracy
Each Calypso Mini AB is individually calibrated in a wind tunnel, with a quality check recorded for wind speed and wind direction. Because the measurement uses no impeller, bearings or other moving parts, there is no mechanical wear of the wind measuring system. The stated accuracy is plus or minus 0.3 m/s at 10 m/s for speed and plus or minus 1 degree for direction, with a measuring range of 0.5 to 45 m/s.
On the Kestrel the wind speed sensor is specified at plus or minus 3 percent of the reading, which at 10 m/s comes down to the same order of magnitude as the Calypso. The real fine tuning on the Kestrel is on the ballistic side, truing. If your impacts do not match the prediction, you train the solver with your actual impact and with muzzle velocity correction, so the ballistic solution fits your rifle and load better and better. In terms of wind accuracy the two are therefore close, the difference is mainly in what they do with that wind afterwards.
Use on the range
With the Kestrel you hold the device up, back to the wind, and read everything off the screen straight away, even in full sunlight thanks to the bright display with white and red night vision backlight. Everything happens on the device itself, you need no phone or extra hardware, although you can link it to your phone via LiNK if you want. That makes the Kestrel especially reliable on the range and at a match, where you do not want to depend on a phone connection.
The Calypso works differently. You screw it onto a tripod via the 1/4 inch thread, place it at your shooting position and line it up with your shooting direction. It then sits there hands-free, measuring the wind and streaming it to the app on your phone or tablet while you stay behind the rifle. The big plus in use is the size, just 78 grams, 43 mm in diameter and 47 mm high, so you always have it with you.
Battery, charging and robustness
The Kestrel runs on a single AA battery. That is handy, because you can replace a dead battery anywhere and lithium AAs perform excellently in the cold. The battery compartment sits safely separated at the back, away from the electronics. The Calypso has a rechargeable battery that you charge wirelessly on a QI pad, good for around 150 hours of active use, which is weeks of range sessions. No cable and no port that clogs up with sand.
In terms of robustness the Calypso has the advantage that there is no moving part that can wear out, and with an IPX8 housing without moving parts it stands up well to the elements. The Kestrel is a proven tough device, with the impeller as its most vulnerable part, although it is fortunately replaceable.
The cost
The price difference is significant, and that makes sense given what you get. The Calypso Mini AB costs 349.95 euro and is a specialised wind sensor. The Kestrel 5700 Elite costs 899.95 euro and is a complete weather meter with a full ballistic computer on board. With the Kestrel you pay for measuring all the climate values and for the computing power that produces the ballistic solution itself. With the Calypso you pay for an excellent, maintenance free wind sensor that leans on the computing power of your phone or tablet.
Specification | Kestrel 5700 Elite | Calypso Mini AB |
|---|---|---|
Type | Weather meter with AB solver | Ultrasonic wind sensor |
Wind measurement method | Impeller (mechanical) | Ultrasonic, no moving parts |
Measures wind direction | Via compass, or automatically with vane mount | Yes, 0-359 degrees without a moving vane |
Climate measurement | Wind, temp, humidity, pressure + calculated values | Wind only (speed + direction) |
Own screen | Yes, high resolution | No, via phone or tablet |
Ballistic calculation | Applied Ballistics on board | No, feeds wind to AB software |
Wind speed range | 0.6 to 40 m/s (down to about 0.4 m/s after start) | 0.5 to 45 m/s (threshold 0.5 m/s) |
Wind accuracy | ±3% of the reading* | ±0.3 m/s at 10 m/s, direction ±1 degree |
Power | 1x AA battery | Rechargeable, QI wireless, 150 hours |
Connectivity | LiNK Bluetooth, up to about 30 m | Bluetooth 5.1, up to 30 m |
Protection / size | Handheld weather meter | IPX8, 43 mm, 78 grams |
Mounting | In hand / tripod / vane mount | 1/4 inch thread on tripod |
Origin | USA (Nielsen-Kellerman) | Spain, individually calibrated |
Price at hop.nl | 899.95 euro | 349.95 euro |
*Per the Kestrel specification this is the larger of 3% of the reading, the display resolution or the minimum stated error.
Can the Kestrel and Calypso complement each other?
You can use both alongside each other, but not by simply letting the Calypso feed live wind into your Kestrel, because that is not the standard workflow. A sensible combination looks more like this, your Kestrel independently provides your atmospheric data and your ballistic solution, while the Calypso continuously measures the wind and passes it over Bluetooth to the Applied Ballistics software, for example AB Quantum on your phone or tablet. Keep in mind that the Calypso, AB Quantum, a Kestrel and, say, a HUD do not all talk to each other directly at the same time, so you deliberately choose which devices link together in your workflow. For many shooters it is therefore more of an either-or choice than an automatic combination.
Together with a ballistic rangefinder, the TANGO FIRE4000 Elite
If you want to run everything from your rifle, the TANGO FIRE4000 Elite is worth a look, a weapon-mounted rangefinder with its own ballistic calculator that also works standalone. The Calypso sends its real-time wind data straight to the FIRE4000, so your current wind is taken into the rangefinder's ballistic calculation right away. The Kestrel can be combined with the FIRE4000 too. That way you build a compact setup where you measure, calculate and aim without leaving your position.
TANGO FIRE4000 Elite
Weapon-mounted rangefinder with its own ballistic calculator, also works standalone.
Which one should you choose
Choose the Kestrel 5700 Elite if you want a standalone device that measures wind and climate and produces the full ballistic solution itself and shows it on its own screen, without depending on a phone. Ideal for the competition shooter and the ELR shooter who wants everything in one rugged device, and who wants to measure the climate values on the spot.
Choose the Calypso Mini AB if you use the Applied Ballistics software and are looking for a compact, maintenance free wind sensor that also measures wind direction automatically and feeds live wind into that software. Ideal for the PRS or precision shooter who wants hands-free live wind in their app, and for anyone who wants a small, robust and sharply priced wind meter that always comes along.
Still unsure which one fits the way you shoot? Feel free to get in touch, we are happy to help you find the right choice for your discipline and budget.
