Scalar Units

Units单位详解：

• speed units

SPEED_UNIT = {
    "meter_per_second": 1.0,
    "mps": 1.0,
    "kilometer_per_hour": 0.277777778,
    "kmph": 0.277777778,
    "kph": 0.277777778,
    "mile_per_hour": 0.447038889,
    "mph": 0.447038889,
    "miph": 0.447038889,
    "mmph": 0.000000278,
    "millimeter_per_hour": 0.000000278
}

• acceleration units

ACCELERATION_UNIT = {
    "meter_per_sec_sqr": 1.0,
    "mpsps": 1.0,
    "mpss": 1.0,
    "kilometer_per_hour_per_sec": 0.5270462769,
    "kmphps": 0.5270462769,
    "mile_per_hour_per_sec": 0.6686096686,
    "miphps": 0.6686096686
}

• length units

LENGTH_UNIT = {
    "nanometer": 0.000000001,
    "nm": 0.000000001,
    "micrometer": 0.000001,
    "millimeter": 0.001,
    "mm": 0.001,
    "centimeter": 0.01,
    "cm": 0.01,
    "meter": 1.0,
    "m": 1.0,
    "kilometer": 1000.0,
    "km": 1000.0,
    "inch": 0.0254,
    "feet": 0.3048,
    "mile": 1609.344,
    "mi": 1609.344
}

• time units

TIME_UNIT = {
    "millisecond": 0.001,
    "ms": 0.001,
    "second": 1.0,
    "sec": 1.0,
    "s": 1.0,
    "minute": 60.0,
    "min": 60.0,
    "hour": 3600.0,
    "h": 3600.0
}

• angle units

ANGLE_UNIT = {
    "degree": 57.295779513,
    "deg": 57.295779513,
    "radian": 1.0,
    "rad": 1.0
}