Geosurvey, Gravsurvey, A Question on SP.

[xenoscepter (OP)]

How many Survey Points Per Hour is "good enough"?

I'd like to get a ball-park estimate to know whether or not my Survey Ships are over-kill or under-kill.

[DeMatt]

My opinion is that the other specs of the survey ship - speed, range, endurance - matter more than the time it spends loitering in orbit.   Doubling the sensors (and keeping all the other parameters the same) would require doubling the rest of the ship - double the engines, double the fuel, double the crew quarters, etc.   So, one sensor per surveyor.

[Father Tim]

My opinion is that the other specs of the survey ship - speed, range, endurance - matter more than the time it spends loitering in orbit.   Doubling the sensors (and keeping all the other parameters the same) would require doubling the rest of the ship - double the engines, double the fuel, double the crew quarters, etc.   So, one sensor per surveyor.

I disagree with your math -- or maybe just the way you wrote it.  I agree that travel time, deployment length, etc., all have a huge effect on how fast one ship can survey a system, but that doesn't mean that simply sticking one more sensor on it (with no other change) can't have a noticable impact.

Conveniently, Aurora tells us how many points are required to survey a grav location or system body, so we can do some quick math and figure out how many hours a ship spent sitting still surveying (the only place additional sensors help).  Watching fuel can tell you how many hours were spent moving around.  The ratio should give you a decent indication of where to best improve your survey efforts.

I'd like to get a ball-park estimate to know whether or not my Survey Ships are over-kill or under-kill.

With a conventional start, I build a 'single geo sensor, single small engine, absolute minimum everything else I can get away with' ship as quickly as possible to survey my home system.  My real survey ships take years longer and tend to have two of everything (because my empires believe in a little redundancy, and because my fiction imagines a certain amount symmetry in my vessels).

Virtually evey survey ship I ever design for any empire/game gets a variant designed with "just one more sensor" or "one more engine" or "one more fuel tank" etc.  I keep checking the effectiveness these theoretical designs to see if I should modify my real survey ships.

For example, if adding a third geo survey sensor (with no other changes) drops the speed of the ship 2%, it's probably worth it.  Whereas if adding another standard fuel tank boosts the ship's range from three months to four at full throttle, but drops the speed to the point where life support won't last that long, it's a bad idea.

- - -

The fastest first-order-approximation method is to compare fuel used to life support duration after one system survey.  If your ship burned 1/10th of its fuel and half of its deployment time, you probably want to triple (or more) its sensors.

[Garfunkel]

Yeah, what Father Tim said. If you're just playing one faction with NPR/spoiler opponent, you're not usually in a hurry to survey things. But if your deployment time consistently runs out before your fuel does, it might be a time to add another sensor. Plus, do you really want to wait a week for a planet to be surveyed? Number of SP needed depends on body size after all. Grav survey sensors are military tech, so they might break - you always want at least two for redundancy there.

I quite often do what Father Tim does - make a barebones geo-survey ship for Sol, later a barebones grav-survey ship for the same purpose, and then once interstellar surveying becomes necessary, I design bigger and better surveyors for that job.

So really xenoscepter, either go with 2 sensors to start with and adjust later, or count the average or median amount of points required for a system and do some napkin math.

[Michael Sandy]

There is one advantage that large survey ships have, and that is that they can have enough maintenance supplies to repair a survey sensor.  But that is it.  I find it is a lot better to have the ability to split up the survey force.  I have 4-6 grav survey boats per system.  And depending on how many large gas giant moon systems there are, 1-3 geo survey ships.

If I really want to get a large super-terrestrial surveyed quickly, I can always put several survey ships in a single task group.

I suppose the other advantage of a large survey ship is that it requires fewer good survey officers, but I have a flag ship for my survey group with the high survey officers giving their bonus to the whole flotilla.

Smaller survey vessels will generally be detected less, and if they are, will be separated by enough distance so some of them could get to safety, or at least, report details of what killed their fellow.

I do suggest having a survey support carrier that has enough maintenance supplies to repair sensors.

[Iranon]

Most systems aren't as crowded as Sol, so initially SP/hour are more important and later on speed/endurance are.
Similarly, short-distance freighters/colony ships focus on cargo handling over speed/payload.

I prefer one size-50 commercial engine for Geosurvey ships, 2-5 geo sensors (no more than 3 with advanced versions) and a few size-1 sensors for situation awareness.
Grav survey varies, I rather like fighters with a single sensor for this. Less likely to antagonise aliens, more expendable if they do.

[Michael Sandy]

I experimented with grav survey fighters, but I really don't like them.  You just can't fit a decent engine into them, so they just don't have good speed or range.  800-1000 tons is about right, in my opinion.

Shipyard tooling is a major factor in my survey fleet design.  Usually, starting from conventional start, I build my geosurvey ships in my first naval shipyard.  So they are small, but the yard can churn them out fast.  And the shipyard is well positioned to start producing survey support carriers and/or jump tenders.  I experimented with jump stations with commercial jump engines, but those tend to require 15000 tons or more, and requires my core fleet to be commercial engined or parasite craft.  Which works, but I wasn't happy with it.

One of the factors that may prompt larger geosurvey ship design is building it in a commercial shipyard.  It takes the same time to build a 4000 ton design in a 10,000 ton commercial yard as to build an 8,000 ton one, and the latter will have its own jump engine.

    Kepler class Gravitational Survey Vessel    800 tons     16 Crew     159 BP      TCS 16  TH 36  EM 0
    2250 km/s     Armour 1-7     Shields 0-0     Sensors 1/1/1/0     Damage Control Rating 0     PPV 0
    Maint Life 5.55 Years     MSP 62    AFR 10%    IFR 0.1%    1YR 3    5YR 51    Max Repair 100 MSP
    Intended Deployment Time: 36 months    Spare Berths 0   

    Pinnace NP 12 EP Nuclear Pulse Engine (3)    Power 12    Fuel Use 33.42%    Signature 12    Exp 7%
    Fuel Capacity 100 000 Litres    Range 67.3 billion km   (346 days at full power)

    Gravitational Survey Sensors (1)   1 Survey Points Per Hour

    This design is classed as a Military Vessel for maintenance purposes


And I tried making fighters, which were only slightly cheaper, but this Ion version was slower than the NP Kepler.

    Brahe Ion class Gravitational Survey Vessel    490 tons     14 Crew     136.48 BP      TCS 9.8  TH 17  EM 0
    1734 km/s     Armour 1-5     Shields 0-0     Sensors 1/1/1/0     Damage Control Rating 0     PPV 0
    Maint Life 11.4 Years     MSP 87    AFR 3%    IFR 0.1%    1YR 1    5YR 18    Max Repair 100 MSP
    Intended Deployment Time: 21 months    Spare Berths 0   

    Pinnace Ion 16.8 EP Ion Drive (1)    Power 16.8    Fuel Use 28.13%    Signature 16.8    Exp 7%
    Fuel Capacity 40 000 Litres    Range 52.2 billion km   (348 days at full power)

    Gravitational Survey Sensors (1)   1 Survey Points Per Hour

    This design is classed as a Fighter for production, combat and maintenance purposes

[Garfunkel]

I've tried Geosurvey fighters but the amount of micro they require killed the concept for me. I could do it for one system, but not longer than that. FACs are better if you want to go Survey Carrier route and they work for Grav surveys as well.

[Michael Sandy]

Next play through, I think I will go with minimum commercial engine size for my geosurvey.  They will be slightly slower, but significantly cheaper.  The only problem is that the jump tenders I make for my first generation survey ships won't be as large as my survey support carriers, or I will need an extra shipyard for upgrading my survey ships.

Although, currently I don't really upgrade my geo survey ships. 

My practice of max sized commercial engine for geo survey dates back to when I used commercial engines to survey Sol.

[CharonJr]

I am pretty much at the same stage with my AAR. And I think (as nearly always) it depends

When you have lots of time - e.g. Jump Drives still being researched - you can go with a cheaper and slower fighter chassis. But when you don't have to wait for anything a FAC is way better. I even managed to cram enough engineering into the FAC to get 1 sensor repair and still decent speed for Ion Tech.

Code: [Select]

Kopernikus Shuttle Mk2 class Gravitational Survey Vessel    498 tons     13 Crew     143.4 BP      TCS 9.95  TH 15  EM 0
1507 km/s     Armour 1-5     Shields 0-0     Sensors 1/1/1/0     Damage Control Rating 0     PPV 0
Maint Life 4.91 Years     MSP 45    AFR 7%    IFR 0.1%    1YR 3    5YR 46    Max Repair 100 MSP
Intended Deployment Time: 29 months    Spare Berths 0   

25% Overdrive 15 EP Ion Drive (1)    Power 15    Fuel Use 138.35%    Signature 15    Exp 12%
Fuel Capacity 100 000 Litres    Range 26.1 billion km   (200 days at full power)

Gravitational Survey Sensors (1)   1 Survey Points Per Hour

This design is classed as a Fighter for production, combat and maintenance purposes
Ressources: 143 BP, 20 Dura, 10 Boro, 6 Merc, 100 Uri, 8 Gal

Code: [Select]

Kopernikus FAC class Gravitational Survey Vessel    900 tons     21 Crew     209.9 BP      TCS 18  TH 48  EM 0
2666 km/s     Armour 1-8     Shields 0-0     Sensors 8/1/1/0     Damage Control Rating 0     PPV 0
Maint Life 9.33 Years     MSP 109    AFR 8%    IFR 0.1%    1YR 2    5YR 34    Max Repair 100 MSP
Intended Deployment Time: 107 months    Spare Berths 0   

EP1 FC 08 1HS 12 EP Ion Drive (4)    Power 12    Fuel Use 79.2%    Signature 12    Exp 10%
Fuel Capacity 190 000 Litres    Range 48.0 billion km   (208 days at full power)

Thermal Sensor TH1-8 (1)     Sensitivity 8     Detect Sig Strength 1000:  8m km
Gravitational Survey Sensors (1)   1 Survey Points Per Hour

This design is classed as a Military Vessel for maintenance purposes
Ressources: 210 BP, 42 Dura, 21 Boro, 15 Merc, 108 Uri, 24 Gal

And while it is nice that no shipyard is needed and the fighter is cheaper the FAC is nearly twice as good in most categories and in addition can repair 1 sensor failure. And it even has a dedicated Thermal Sensor which will get better over time. Basically I agree with Michael Sandy.

In addition I really like FACs anyway, so I can use the additional small shipyards anyway.

[Michael Sandy]

Survey boats (501-1000 tons), are nice because crew quality affects survey time.  So if you have a 10 year old survey ship that has had a +crew training officers, it will have a significant bonus to its survey speed.

I have mixed feelings about giving significant sensors to survey ships.  I will give them a .1 HS active sensor, so they can tell me information about a beam ship that kills them, and geo-survey ships can use them to detect ground troops, but I prefer to have dedicated scouts with my survey fleet.  Scouts which have a much larger sensor to cross-section ratio than a survey ship could ever have, and much more speed.

The Kopernikus survey fighter and FAC seem to have a non-ideal engine to fuel ratios.  To get the most range/speed, you want an engine:fuel HS ratio of approximately 2.5 to 1.

I will typically go 3 HS of engine to 1 HS of fuel, simply because small fuel tanks drive up the cost.

People are going to optimize their survey ships differently.  I am willing to have the occasional grav sensor failure requiring the survey ship return to base or tender in order to get more survey ships that are slightly faster.  I also tend to recall my grav survey ships to get their maintenance clocks rewound pre-emptively.  That costs survey up-time, and is probably not as good a policy as the frontiers expand and the time spent getting to survey station increases.  However, I also either tug a CV space station to forward colonies or assemble a PDC CV there to support survey efforts.  My early colonies tend to be dominated by archaeology efforts, so I tend to have a lot of construction brigades at them who can assemble forward PDC CVs.

[SpikeTheHobbitMage]

I usually use teams of three 1kt corvettes* for grav survey which can only fit one sensor each.  Two Engineering Spaces gives them about 20 years rated maintenance life, so about 10 years before their first failure.  A 2500t commercial tender will fit a 3kt military jump drive with room for extra fuel to extend their range.

*Not classed as FACs because they use minimum power engines.  Fast they are not.

Since Geosurvey ships can be commercial I often use 2500t self-jumping ships once I start expanding in earnest.  Depending on tech level these can fit a second survey sensor.  I include a size 1 thermal sensor to find those pesky DSTS outposts some spoilers like to leave scattered around.  While of little strategic value they do cause interrupts every time a civilian ship enters or leaves their range, which can be annoying in a high traffic system.

One Geosurvey ship can take a while to fully survey a large system, but if you set it to survey planets and moons first it doesn't really matter.