From looking at the attached pictures that is the prior generation sensor array. It lis like the Fine Offset HP1000, Ambient WS-1002-WiFi which Ambient finally lists as discontinued. Sometimes depending on vendor it was called HP2000. Now we haven't seen the display and it is possible to have the WS-2902A display with that sensor array with the correct firmware so it could be like the Fine Offset WH2950. The WH2950 is like a hybrid older generation sensor array with newer WS-2902A style display console. Okay well none of this really matters as it is the sensor array that is the focus. And for that matter it is definitely not current generation stuff. We do have a unique name for that old sensor array...that is the WH24 (and yes it is compatible with the GW1000).
Now that we have established what it is, I agree with Mandrake that getting the Ecowitt GW1000 (with matching frequency; 433, 868, or 915 MHz) would probably be the simplest method. You don't want to strap an Arduino directly to the sensors. Because then you need to worry about weather proofing that attachment and then getting data from it (wired or wireless). It would be like reinventing the wheel. The sensor array already transmits. If you want to pick up the data then use the gateway console GW1000 or build an SDR. But I'm not sure how simple SDR would be on Arduino. Probably a better task for Raspberry Pi to do SDR. Or keep is simple and just get the GW1000 and then run some weather software on a Raspberry Pi like Cumulus, Weather-Display, or WeeWx....or add a Meteobridge paired up with the GW1000.
If the focus is to build a DIY Arduino based weather station as a fun project, then I would have gotten separate sensors and not complete station. That way you can learn micro programming with direct sensors attached. There are plenty of examples of how to do this and which sensors to use and even sample code. There are even kits that are sold this way. I see these more as a learning tool than a way to build a reliable weather station.
