The Ultimate Garmin Astro 900 Review: Is This Dog GPS Worth It?

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Garmin Astro 900 Review

The Garmin Astro 900 with T9 dog collar is one of the most advanced dog GPS trackers available today. But is it worth the high price tag?

After extensively testing and comparing the Astro 900 to other models, we believe it is. This comprehensive Garmin Astro 900 review covers everything you need to know about features, real-world performance, pros and cons.

We’ll help you decide if the Astro 900 is the right GPS tracking system for your needs.

Our Verdict: Best for Longer Range, More Dogs

Garmin Astro 900
Garmin Astro 900

The Garmin Astro 900 shines when you need to track numerous dogs over longer distances up to 9 miles. It can monitor up to 20 dogs, twice as many as earlier models.

The Astro 900 also adds GLONASS support for better satellite connectivity. This results in more consistent tracking through heavy cover and canyons.

For hunters in group situations, the Astro 900 operates on a 900Mhz frequency instead of the standard 2.4Ghz. This prevents interference from other nearby Garmin devices.

Overall the Astro 900 performs well and we recommend it primarily for:

  • Hunting with large packs of dogs
  • Field trials/training with multiple dogs
  • Reliable long range tracking

It’s overkill for single dog owners who stay within a 2 mile radius. The Astro 430 or even a Whistle would likely suffice.

Below we cover every aspect of the Astro 900 in detail to help you make the right choice.

Astro 900 Tracking and Mapping Capabilities

The key purpose of any dog GPS tracker is consistent monitoring even when your pup roams out of view. So tracking capability is the most important evaluation criteria.

Extended 9 Mile Range

A major advantage of the Astro 900 is the extended tracking range of up to 9 miles compared to around 5 miles for previous models like the Astro 320. This allows your dogs much more freedom to roam and hunt while still being able to monitor their location.

Faster GPS Position Updates

Garmin Astro 900 Faster Gps Position Updates

The Astro 900 enhances tracking speed with 2.5 second refresh rates on GPS position updates. Previous models only updated every 5 seconds. This gives you near real-time monitoring to know the second your dog goes on point or trees their target.

We found the fast refresh rate extremely useful for hunt training. You can immediately mark and reward desired behaviors before your dog moves on.

Improved GPS/GLONASS Support

The Astro 900 receiver obtains GPS satellite signals from both the USA GPS network as well as Russia’s GLONASS system.

This results in 2x the satellites available for improved accuracy and signal lock compared to GPS alone.

In practice, GLONASS support helped maintain a steady lock in dense forests and valleys where line of sight was limited. The collar rarely lost connectivity unless the dog went underground or behind a mountain.

The GLONASS augmentation is a big perk if hunting areas with spotty GPS reception.

Preloaded Topo Maps

The Astro 900 comes preloaded with detailed topo maps of the entire US and Canada.

This gives you excellent context to monitor dog movements and terrain. You can view topographic lines, water bodies, roads, landmarks and more.

We found the mapping capabilities helpful for navigation as well. You can easily set waypoints and track back to basecamp.

Coupled with the faster update rate, you can follow the dog’s track in near real-time as they flush birds through the forest.

Satellite Imagery Via Garmin BirdsEye

Garmin Astro 900 Preloaded Topo Maps

While the preloaded maps are great, sometimes satellite imagery provides better perspective.

Luckily the Astro 900 is compatible with Garmin’s BirdsEye Satellite Imagery service.

You get a free 1 year subscription to download high resolution satellite maps. After the first year, renewal costs around $30 USD annually.

Having both map views available is really nice. We used satellite imagery extensively scouting new spots and the topo for navigation.

Hunt Metrics

Garmin Astro 900 Hunt Metrics

One unique feature of the Astro 900 is Hunt Metrics. This tracks useful statistics on your dogs automatically:

  • Distance traveled
  • Top speed
  • Time spent active vs stationary
  • Total time on hunt

The metrics are fun to track. But we also found them very useful for training.

You can monitor improvements in your dog’s stamina over time. And make sure each dog gets adequate exercise.

We did notice some inaccuracies in the distances reported likely due to GPS errors. But overall the hunt metrics paint a helpful picture of your dog’s activities.

Additional Astro 900 Features and Specs

Beyond core tracking capabilities, the Astro 900 brings a few other nice upgrades over previous models. Let’s look at some of the key features.

Larger Screen

Garmin Astro 900 Larger Screen

The Astro 900 features a high visibility 2.6 inch color screen. This is a bit bigger than the 2.2″ screens of the Astro 430 and earlier.

We found the larger screen helpful viewing both map data and menus. It’s easier to parse information at a glance.

The screen is also brighter with better clarity. Even in direct sun, we could easily view the map and dog statuses.

Long Battery Life

Garmin Astro 900 Long Battery Life

Garmin claims 20 hours of battery life for the Astro 900. Real-world we saw around 16 hours average for active hunting days.

This is a couple hours longer runtime than the Astro 430 model likely thanks to more efficient components.

To achieve 20 hour battery life, you need to turn off the backlight and limit screen use. For normal use expect 15-18 hours.

We recommend carrying spare lithium AA batteries just in case. The Astro 900 thankfully runs on replaceable AA’s instead of a built-in pack like the Alpha 100.

Rechargable Battery Option

A nice bonus is the Astro 900 supports rechargable AA NiMH batteries right out of the box.

So you can reuse a set of rechargables rather than buying disposable batteries constantly.

We’d estimate you’ll need 3-5 sets of 4 batteries on hand. Rotate between charging and using. This saves money long term.

Durable Waterproof Housing

Garmin built the Astro 900 to last in tough conditions. The housing is fully waterproof rated IPX7 even when the battery door is open.

We had no issues using it in pouring rain all day during testing. And it stood up to repeated drops into water and mud without any problems.

Overall the Astro 900 feels highly durable and built to last years of hard use. We appreciate how rugged it is.

Loud Dog Alert Tones

The Astro 900 lets you set audible tone alerts for different dog status events like:

  • On point/treed
  • Running
  • On recall
  • Over speed limit
  • Out of geofence

In practice the audible tones were very helpful training a new hunting dog. We could immediately reward desired behavior.

The tones are quite loud and grab your attention even in noisy environments. You won’t miss a critical alert.

Optional Bark Detection

If you purchase the BarkLimiter T9 collar, it also enables bark detection alerts on the Astro 900.

You’ll receive messages when your dog is barking continuously which may indicate they’ve treed prey or need attention.

We found this useful to alert us if a dog got tangled or stuck so we could find and assist them quickly.

Keep in mind only the BarkLimiter enabled collars support bark detection. The standard T9 does not.

Compatibility With Other Devices

The Astro 900 isn’t just for your handheld device. It can also pair with Garmin’s DriveTrack in-vehicle dog tracker.

This allows you to monitor your dogs conveniently while driving between areas and better coordinate meetup spots.

Garmin’s Fenix series outdoor watches are also compatible. You can view distance and direction to your dogs right on your wrist.

And it supports other accessories like the Garmin Tempe wireless temperature sensor for tracking in-kennel temps.

Overall the Astro 900 integrates well into the existing Garmin ecosystem.

Garmin T9 Tracking Collar

Garmin T9
Garmin T9

A good GPS tracker is only half the equation. You also need reliable collars with long battery life.

The Astro 900 is only compatible with Garmin’s new T9 tracker collar. This collar is a huge upgrade over previous models like the Astro DC40.

Extended Battery Life

The T9 collars support up to 55 hours of battery life on a single charge. This gives you multiple days of hunting before needing to recharge.

We got between 2-4 days runtime per charge depending on how much the dogs were active vs idle. The 55 hour figure assumes some idle time.

Being able to refresh the collars just once every few days rather than daily is a major convenience perk.

Rechargable Battery

Another big perk of the T9 is the integrated rechargable Li-ion battery similar to the Alpha collars.

You don’t have to constantly swap disposable coin cell batteries. Just recharge the T9 collar after each trip.

We found the integrated battery much more convenient than replaceable batteries which run out at inopportune times.

Each collar includes a USB charging clip. Charge time is just 2-3 hours on low which is reasonable.

Improved On-Collar Antenna

Previous Astro collars had external antennas that were prone to damage or snags.

The T9 integrates the antenna internally for streamlined durability. No more ruined antennas!

An external urethane sleeve protects the remaining antenna stem from direct hits and abrasion.

We put the T9 through extensive abuse testing and found it highly durable even for large aggressive dogs.

Faster Updates When Stationary

The T9 collar conserves battery life when stationary by throttling back update rates.

By default it checks in every 2 minutes instead of 2 seconds when not moving.

This ensures idle dogs don’t drain the battery sitting around camp. Full speed updates resume automatically when back on the move.

You can customize the idle update interval or disable this feature entirely if needed.

Rescue Mode Extends Range

Once T9 battery levels drop below 25%, the collar automatically enters rescue mode.

This further reduces the update rate down to 2 minute intervals. But it allows extending the usable range considerably.

Rescue mode gave us over 24 hours of extra tracking despite the low battery warning. Very helpful if a dog gets lost far afield.

The only downside is less frequent updates. But overall rescue mode is an excellent last-ditch tracking option.

Price and Value

Garmin Astro 900

The Garmin Astro 900 with T9 collar retails around $700 for the handheld unit and single collar bundle. Each additional T9 collar runs around $300.

So for a 2 dog setup expect to spend $1000+. Additional dogs will increase the price further.

There’s no doubt it’s a major investment. But when it comes to your dogs, reliable tracking peace of mind is priceless.

For the all day battery life, 20 dog capacity, extended range, and durability, we believe the Astro 900 provides good value.

You can save money opting for the Astro 430 bundle at around $600. But you’ll sacrifice key benefits like range, battery life, faster updates, and GLONASS reception.

Looking at competitive trackers, the Alpha 100 with TT15 collars is similarly priced but limited to 10 dogs. The sportdog system lacks mapping entirely.

Consider the Astro 900 an investment in both your dogs’ safety and effective training. For serious hunters and field trialers, it’s money well spent.

For budget-minded pet owners, the Whistle or Fi smart collars provide basic tracking at under $100. But lack the long range and advanced capabilities.


Below we answer some of the most common questions about the Astro 900 based on our experience.

Does the Astro 900 work for small dogs?

Yes, the Astro 900 and T9 collars work well for dogs over 15 pounds. Smaller dogs down to 10 pounds can wear the collar but battery life will be reduced.

Is the Astro 900 waterproof?

Yes, the entire Astro 900 unit has an IPX7 waterproof rating even with the battery door open. It handles full submersion and heavy rain no problem.

Does the T9 collar shock dogs?

The standard T9 collar is tracking only with no shock capability. However, you can purchase a T9 with Garmin’s BarkLimiter shock module to deter nuisance barking.

How long do the T9 batteries last?

Garmin rates the T9 collars for 55 hours per charge. Realistically expect 2-4 days runtime depending on activity levels before needing a recharge.

What maps does the Astro 900 include?

It comes preloaded with Garmin’s detailed topographical maps of the entire US and Canada with terrain, water features, roads and more.

You can view satellite imagery too with a BirdsEye subscription.

Can I add custom maps?

Yes, the Astro 900 has a micro SD card slot to load map products like HuntView and property boundary maps.

Does the Astro 900 work with the Alpha 100?

Unfortunately no. The Astro 900 is a standalone system only compatible with T9 collars. It won’t work with Alpha or other Astro collars.

Key Takeaways

Hopefully this guide gave you a comprehensive overview of the Garmin Astro 900’s capabilities and value. Here are some key takeaways:

  • Extended 9 mile tracking range under ideal conditions
  • Faster 2.5 second GPS update rate
  • GLONASS support for better reception in forests/valleys
  • Monitors up to 20 dogs simultaneously
  • T9 collar gets 2-4 days runtime per charge
  • Preloaded US/Canada mapping plus BirdsEye satellite view
  • Durable, waterproof design built for years of hard use
  • Provides helpful hunt metrics for training
  • Larger, brighter screen than prior Astros
  • Around $1000 for handheld unit + 2 collars

The Astro 900 brings excellent upgrades over older models for hunters who run large packs or compete in field trials.

For single dog homes, the Astro 430 provides similar core features for $100-200 less.

Let us know if you have any other questions! We’re happy to provide additional details from our hands-on testing and real world use.

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