x-bit-astro-imaging

Seestar S50 - Wi-Fi range extension

Introduction to the Seestar S50

The ZWO Seestar S50 is a smart altazimuth telescope. It is a 50mm apochromatic triplet with a built in UV/IR cut filter and a dualband 20nm H-alpha and 30nm (OIII, H-beta) light-pollution filter (atumatically or 'manual' placed in the light path. It has a built in camera which uses the Sony IMX462 CMOS sensor which has a resolution of 1920 x 1080 pixels (2 MP). The Seestar S50 has a focal length of 250mm, and a focal ratio of f/5. For solar observing/imaging, a solar filter is provided. It has a built in dew heater and the Seestar software, which runs on Android or iOS can control the scope and autofocusing. The Seestar S50 can be set to capture 10s 20s or 30s exposures or video (which can be RAW or MP4). Being an altazimuth mount, if long exposures are being used, it will depend on which part of the sky and elevation one is imaging, which exposure it will be reasonable to use. Our initial deep sky imaging was done with 10s exposures.

The scope plate solves to centre the object once located. The built in compass aids the telescope in finding it's targets. Once located and centred (which is a quick process) the scope can be set to start capturing. It captures exposures and does a live stack so you can see the image building up on the screen. (We used a 10.4 " Android tablet to get a really good view of the developing image.)

Before the scope starts capturing images, it prepares by capturing darks which are then applied in real time to the captured images. It is possible to save just the stacked image, or, as we did, to save each of the individual exposures so that they can be stacked and processed in other software.

Equipment Required to extend the Seestar S50s Wi-Fi range

1. Two high frequency ethernet over mains adapters.

2. Wi-Fi Repeater/Access point configured as a Wireless Access Point.

3. A Seestar S50 operating in Station Mode The Seestar S50 broadcasts its own network.

Ethernet over mains Adapters

Ethernet over mains adaptors are devices that are capable of routing data via electrical power lines. In order to set up a powerline network, two ethernet over mains adapters are needed. Each device consists of a standard mains plug (containing the appropriate circuitry) with an RJ45 ethernet port.

The first device is connected directly to the local local area network in the house via ethernet and is plugged into a standard mains AC socket. The second device is plugged into the AC outlet of the long mains extension lead out by the Seestar S50, and its ethernet port carries the same data signal as the first. Once the devices are connected, they automatically negotiate the fastest stable speed.

Wireless access point

A wireless access point (AP) is a device that takes a direct ethernet connection and transmits the signal wirelessly. The device essentially creates an independent wireless network which can have its own SSID and wireless password, however, the parameters can be the same as the primary network if required.

Procedure

A power extension lead is plugged into a standard mains outlet and the other end is taken to the desired remote location close to the Seestar S50. At the remote location, a wireless access point is plugged into the extension together with an ethernet over mains adapter and the two are connected via a short ethernet cable. The local side of the network (in the house) consists of an ethernet over mains adapter connected directly to the local area network via an ethernet cable.

Everything connected to the Seestar S50 at a distance from the house

The Seestar S50 telescope is taken to an imaging location and the the wireless access point plus ethernet over mains is placed close by. A tablet computer is then connected to the Seestar S50 in the usual way, once the connection is established, the Seestar’s Station Mode is activated and is connected to the remote wireless access point.

This process projects the Seestar S50 onto the primary network which allows a tablet computer (or smartphone) to be used anywhere that is within range of the primary wireless network. In addition to extending the Wi-Fi of the Seestar S50, this has the added benefit of providing power to the Seestar S5 telescope/mount if required, by means of a Mains/USB charger via the USB C port on the Seestar S50 so that it is not reliant on its internal battery if it is going to be in operation for a long time and maybe using its internal dew heater.

Mains-USB charger

The complete Seestar Wi-Fi extender kit

This procedure will allow the user to control the Seestar S50 from the comfort of indoors whilst the Seestar S50 is placed at a distance from the house in a place where it has optimal access to the night sky for imaging.

We tested the system with the Seestar S50 in Scenery mode. We were able to slew the scope and autofocus on objects at a distance whilst being in the house, well ouside the normal Wi-Fi range of the SeestaS50 which would have been exacerbated by the thick stone walls. The ethernet over mains brought the signal into the house network and it worked perfectly.

A tree across the valley